I , I : CORNE LL UNIV ERSITY THE FOUNDED BY ROSWELL P. FLOWER for the use of the N. Y. STATE. VETERINARY COLLEGE 1897 This Volume is the Gift of .])_%. ..Leon-S-vBeardsi-ev 3 1924 104 224 724 The original of tiiis bool< is in tine Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://archive.org/details/cu31924104224724 TEXT- BOOK OF OPHTHALMOLOGY BY Dr. ERNEST FUCHS PROFESSOR OF OPHTHALMOLOGY IN THE UNIVERSITY OF VIENNA authorized translation, revised from the seventh enlarged and improved german edition By a. DUANE, M. D. ASSISTANT SURGEON OPHTHALMIC AND AURAL INSTITUTE NEW YORK WITH TWO HUNDRED AND SEVENTY-SEVEN ILLUSTRA TIONS SECOND AMERICAN EDITION NEW YORK D. APPLETON AND COMPANY 1901 Copyright, 1892, 1899, bt d. applbton and company. Electeotyped and Printed AT THE Applbton Press, U. S. A. PREFACE TO FIRST EDITION. No apology seems needed for presenting to American readers the translation of a book so well and so favorably known as Prof. Fuch's Lehrbuch der Augenheilkunde. The care and judicious spirit govern- ing the selection and presentation of facts, the thoroughness and fresh- ness of the information, and the scientific accuracy which characterize the original, have won for it the first place among ophthalmological text-books. To t^ese essential properties there is superadded one scarcely less important in a book of this character, namely, a clear, concise, and pleasing style. In the endeavor to make his version worthy of the original in this important regard, the translator has taken considerable liberties with the German text, and has not hesi- tated to alter grammatical relations, substitute and interpolate words, and in other ways depart from the strict letter of his model whenever it has seemed to him that clearness and the necessities of the English idiom required the change. Upon this point he is glad to say that he has the entire approval of Dr. Fuchs, who has not only given his au- thorization to the work of translation, but has been good enough to look over and indulgent enough to commend that portion of the book submitted to his inspection. In consonance with his views of a translator's duties, the author of the present version has made only such additions as seemed necessary to adapt the book to American readers. These additions are every- where distinguished by being inclosed in brackets, and, in the case of footnotes, by having the letter D appended to them. The translator alone is responsible for such insertions ; at the same time, it is but fair to state that a number of them have been submitted to Dr. Fuchs and have received his approval. The appendix containing the cuts of instruments is also matter inserted by the translator. These cuts (and also the two on page 722) iv PEEP ACE TO THE FIRST EDITION. have been kindly furnished by Tiemann & Co., and by E. B. Meyro- witz, the well-known instrument makers of this city, to whom the translator desires here to make suitable acknowledgments for the courtesy extended. It is the hope of the translator that he has succeeded in faithfully reproducing a work the many excellences of which should command for it a wide circulation in this country, as they have already done in Europe. A. DuANE, M. D. 25 East Thirty-first Street, New York, July 6, 1892. PKEFACE TO THE SECOND EDITION. SiisrcE the first edition of this book was published five German editions have been issued. Each of these has been characterized by the addition of important new matter and by the thorough revision of the old. This is particularly the case with the last or seventh edition, which, in addition to the merits of lucidity, judicious treatment of the subject, and excellence of proportion and balance, that have always characterized Prof. Fuch's treatise, bears everywhere the marks of the most thorough revision, of additions and corrections, bringing the book up to date in all its parts, so that it presents an excellent summary of ophthalmological science as we know it to-day. Although alterations will be found on almost every page, the most marked changes will be met with in the sections on functional exam- ination, the pathology of corneal and conjunctival diseases (especially the parts relating to ulcus serpens and diphtheria), and the diseases of the fundus. Over eighty illustrations have been added. The translator has thought it proper to insert two new sections : § 125 A (page 616), upon heterophoria, and § 148 A (page 734), upon the use of homatropine and other cycloplegics and the general subject of the correction of refractive errors. For these insertions, as well as all others of his own (distinguished as in the first edition by being inclosed in brackets) the translator is wholly responsible. In view of the favorable reception accorded the first edition of this work in this country, the translator has little hesitation in offering the second, particularly as it represents an essentially improved form of a work which has already proved to be of value to so many — and of a work, moreover, which, in matter, scope, and treatment, contains so much that appeals both to the professed ophthalmologist and to the general practitioner. Alexander Duane. 49 East Thirtieth Street, New York, March 1, 1899. V OONTEI^TS. PAET I. EXAMINATION OF THE EYE. CHAPTER I. Objective Examination of the Eye. PAGE Examination of the eyes 1 Ophthalmoscopy 4 Principle of the ophthalmoscope 5 Method of examination 6 Luminosity of the pupil 8 Application of the ophthalmoscope— characters of normal fundus . . 9 Examination of the refracting media 16 Determination of the refraction by objective methods (ophthalmoscope, skiascopy) .18 CHAPTER II. Functional TESTiNa. Central and peripheral vision .37 Examination of the field of vision 28 Extent of the field of vision 31 Light sense 34 Simulation of blindness 35 PAET 11. DISEASES OF TEE EYE. CHAPTER L Diseases of the Conjunctita. Anatomy of the conjunctiva 38 Conjunctivitis catarrhalis ** Acuta 44 Chronica _ Pollicularis ^'^ Conjunctivitis blennorrhoica acuta ^4 Blennorrhcea adultorum ■ • • • • ^^ Blennorrhoea neonatorum ^^ vii viii CONTENTS. PAGE Conjunctivitis trachomatosa ^^ Conjunctivitis diphtherica 86 Croupous membranes on the conjunctiva 90 Conjunctivitis eezematosa . 93 Acute exanthemata associated with conjunctivitis 103 Chronic exanthemata associated with conjunctivitis 102 Acne rosacea conjunctivae 102 Pemphigus conjunctivae 102 Lupus conjunctivae 103 Vernal catarrh 103 Amyloid degeneration of the conjunctiva 106 Tuberculosis of the conjunctiva 107 Ulcers of the conjunctiva . . . 109 Injuries of the conjunctiva ' 110 Pterygium 112 Pseudo-pterygium 116 Symblepharon - 117 Xerosis. . 120 Extravasation of serum and blood beneath the conjunctiva .... 122 Tumors of the conjunctiva 124 Affections of the plica semilunaris and caruncle 129 CHAPTER II. Diseases of the Cornea. Anatomy of the cornea 130 Clinical examination of the cornea 184 Inflammation of the cornea 136 General statement . . . ■ 136 Subdivision of keratitis 144 Suppurative keratitis 145 Ulcer of the cornea 145 Ulcus serpens corneas 163 Keratitis e lagophthalmo 174 Keratomalacia 175 Keratitis neuroparalytica 177 Non-suppurative keratitis 180 Pannus 180 Keratitis with the formation of vesicles (herpes febrilis, herpes zos- ter, and keratitis vesiculosa) 181 Kei-atitis punctata superficialis 183 I Parenchymatous keratitis 184 Keratitis profunda 194 Sclerosing keratitis 195 Keratitis springing from the posterior surface of the cornea . . 195 Deep keratitis in irido-cyclitis 196 Deep scrofulous infiltrates 196 Keratitis marginalis profunda 197 Striate opacity of the cornea 197 Injuries of the cornea 198 Foreign bodies in the cornea 198 Solutions of continuity of the cornea 199 CONTENTS. ix PAGE Injuries of the cornea by caustic agents and burns 201 Opacities of tlie cornea 203 EctasiJB ol the cornea 212 Staphyloma of the cornea 212 Kerateotasia 223- Keratoconus 223 Keratoglobus 224 Tumors of the cornea 225 CHAPTER III. Diseases of the Solera. Anatomy of the sclera 226 Inflammation of the sclera 227 Superficial forms of scleritis (episcleritis) 227 Deep forms of scleritis 329 Injuries of the sclera 233 Foreign bodies in the eye 235 EctasifB of the sclera 244 Ulcers and tumors of the sclera 350 CHAPTER IV. Anatomy and Phtsioloot of the Uvea — Embryology of the Eye. Anatomy of the uvea 251 Iris 251 Ciliary body 256 Chorioid 363 Circulation and metabolism of the uvea 365 Blood-vessels 265 Lymph-passages 368 Nutrition of the eye 370 Intra-ocular pressure 272 Participation of the uvea in the visual act 374 Function of iris ; reaction of pupil ; mydriatics and miotics ; function of ciliary body and chorioid 374 Development of the eye 383 CHAPTER V. Diseases of the Ibis and op the Ciliary Body. Inflammation (iritis, cyclitis, irido-cyclitis) 389 Symptoms of iritis 289 Symptoms of cyclitis 893 Differential diagnosis between iritis and cyclitis 297 Course and termination of iritis and cyclitis 302 Etiology and varieties of iritis and cyclitis ; sympathetic irritation and ophthalmia 308 Treatment of iritis and cyclitis 317 Injuries of the iris 323 Tumors of the iris and ciliary body (including cysts and tuberculosis) . . 326 X CONTENTS. PAGE Disorders of motility of the iris 331 Mydriasis 332 Miosis 333 Paralysis of the sympathetic 333 Hippus . . 333 Congenital anomalies of the iris 334 Persistent pupillary membrane 334 Coloboma iridis 334 Irideremia 335 Ectopia pupillse 335 CHAPTER VI. Diseases of the Chomoid. Inflammation of the chorioid 337 Chorioiditis exudativa 338 Chorioiditis and irido-chorioiditis suppurativa ; metastatic ophthalmia ; atrophy and phthisis of eyeball 346 Detachment of the chorioid 352 Rupture of the chorioid 352 Tumors of the chorioid 353 Tuberculosis of the chorioid 356 Congenital anomalies of the chorioid 357 Albinism 361 CHAPTER VII. Glaucoma. General considerations 363 Primary glaucoma 367 Glaucoma inflammatorium 3g7 Glaucoma simplex 373 Hydrophthalmus 374 Theories of glaucoma 37g Anatomy of glaucoma 333 Treatment of primary glaucoma 385 Secondary glaucoma 391 Diminution of the intra-ocular pressure . 393 CHAPTER VIII. Diseases of the Lens. Anatomy of the lens 394 Opacities of the lens, cataract 397 General considerations 397 Clinical forms of cataract 402 Anterior polar cataract 403 406 Posterior polar cataract 493 406 Circumscribed opacities 493 Perinuclear (or lamellar) cataract 404 407 Cortical cataract 406 408 Progressive cataracts (senile cataract) 4Q8 CONTENTS. xi PAGE Etiology of cataract 417 Treatment of cataract 422 Changes of position of the lens 425 Lenticonus 430 CHAPTER IX. Diseases of the Vitbeous. Anatomy of the vitreous 431 Opacities of the vitreous 431 Liquefaction of the vitreous 483 Foreign bodies in the vitreous ; persistent hyaloid artery ; entozoa . . . 483 CHAPTER X. Diseases of the Retina. Anatomy and physiology of the retina 437 Inflammation of the retina ; retinitis 440 Hyperaamia of the retina 443 AnfBmia of the retina ; quinine amaurosis 443 Hffimorrhages into the retina 443 Embolism of the central artery 445 Thrombosis of the central vein 447 Varieties of retinitis ; uremic amaurosis ; retinal disease of infants • . 449 Atrophy of the retina ; retinitis pigmentosa 454 Anatomical changes in inflammation and atrophy of retina . , . 457 Detachment of the retina 458 Glioma of the retina 464 Injuries of the retina 466 CHAPTER XI. Diseases of the Optic Nerve. Anatomy of the optic nerve 469 Intra-ocular division 469 Orbital division 471 Intracranial division 473 Continuation of the fibers to the cerebral cortex ; decussation of the optic nerves ; hemiopia 473 Inflammation of the optic nerve 481 Neuritis intra-ocularis ; hyperaemia of optio nerve ; neuro-retinitis . . 482 Retrobulbar neuritis ; tobacco amblyopia and other toxic amblyopias . 488 Strychnine in eye diseases 491 Atrophy of the optic nerve 491 Injuries of the optic nerve 493 Tumors of the optic nerve 493 Anatomy of affections of the optic nerve 494 Disturbances of vision without apparent lesion 495 Congenital amblyopia 495 Amblyopia ex anopsia 496 Hemeralopia and nyctalopia 496 Amblyopia and amaurosis of central origin 499 xii CONTENTS. PAGE Scintillating scotoma . 499 Hysterical amblyopia and asthenopia 500 Color blindness 501 CHAPTER XII. Diseases of the Lids. Anatomy and physiology of the lids 509 Inflammation of the skin of the lids 518 Exanthemata (erysipelas, herpes zoster, eczema) .... 518, 532 Phlegmonous inflammation 531 Ulcers of the skin of the lids 533 Elephantiasis of the lids 533 Chromidrosis 523 CEderaa of the lids 533 Inflammation of the border of the lids 526 Hypersemia 626 Blepharitis squamosa and ulcerosa 526 Phthiriasis palpebrarum 581 Diseases of the palpebral glands 583 Hordeolum 582 Chalazion 533, 535 Infarcts of the Meibomian glands 535 Affections of the tarsus 536 Anomalies of position and connection of lids 537 Trichiasis and distichiasis 537 Entropion 5G9 Ectropion 541 Ankyloblepharon 544 Symblepharon .544 Blepharophimosis 544 Lagophthalmus 54(3 Diseases of the palpebral muscles ,1548 Spasm of the orbicularis (blepharospasm) 548 551 Paralysis of the orbicularis . _ , 549 Paralysis of the levator palpebra3 superioris (ptosis) .... 550 552 Spasm and paralysis of Miiller's muscle 553 Injuries of the lids 554 Tumors of the lids g5g Congenital anomalies of the lids (coloboraa, epicanthus, etc.) .... 558 CHAPTER XIII. Diseases of the Lachrymal Orgahs, Anatomy and physiology ggO Blennorrhcea of the lachrymal sac 5g4 5^3 Dacryocystitis 570^ 574 Diseases of the lachrymal gland 57^^ Affections of puneta and canaliouli 573 Trachoma and tuberculosis of lachrymal sac 573 Treatment of lachrymal disease 573 Epiphora and increase of lachrymal secretion 573 Abolition of lachrymal secretion 575 CONTENTS. xiii CHAPTER XIV. Disturbances of Motility of the Eye. PAGR Anatomy and physiology of the ocular muscles 57G Anatomy of muscles 576, 585 Action of muscles 578, 580 Orientation and diplopia 580, 590 Measurement of excursions of eyes ; field of fixation 587 Nerves of ocular muscles 588 Binocular and stereoscopic vision ; overcoming of prisms ; divergence and convergence 590 Paralysis of the ocular muscles 594 Latent disturbances of equilibrium ; heterophoria 613, 616 Squint 627 Nystagmus 638 Tonic spasms of ocular muscles 640 CHAPTER XV. Diseases of the Orbit. Anatomy of the orbit 641 Position of the eyeball in the orbit ; exophthalmus 643 Enophthalmus 645 Inflammation 645 Inflammation of the bony wall and the periosteum .... 645, 648 Inflammation of the cellular tissue ; cellulitis 647 Thrombosis of the cavernous sinus . 649 Tenonitis 649 Injuries of the orbit 650 Contusion of the eye ; summary of appearances 653 Basedow's disease 653 Tumors of the orbit ; pulsating exophthalmus 655 Dilatation of the cavities adjoining the orbit 659 PAET III. ANOMALIES OF REFRACTION AND ACCOMMODATION. Introduction 661 CHAPTER I. The Theory of Glasses. Varieties and properties of lenses 663 Numbering of glasses 666 CHAPTER II. Optical Properties op the Normal Bye. Refraction 669 Visual acuity 670 Accommodation 674 Measurement of accommodation 679 Changes of the accommodation in age ; presbyopia ..... 686 xiv CONTENTS. CHAPTER III. Myopia. p^^e Nature and determination . 690 Typical myopia 694 CHAPTER IV. Hypeemetbopia. Nature and determination ^5 Typical hypermetropia 710 CHAPTER V. Astigmatism — The Correction of Refractive Errors. Regular astigmatism 716, 721 Irregular astigmatism 720 Determination of astigmatism . 731 Oyoloplegios and the correction of refractive errors 724 Anisometropia 726 CHAPTER VI. Anomalies of Accosihodation. Paralysis of accommodation 728 Spasm of accommodation . 731 PAET IV. ■ OPERATIONS. CHAPTER I. General Remarks. The antiseptic method in eye operations 733, 740 Anesthesia in operations 735 Instruments for supporting the lids 735 Character and shape of incisions in the eyeball 735, 741 Maintenance of proper position of the iris 736, 743 Haemorrhage in operations 737, 745 After-treatment of operations 738, 745 Regular healing of operation wounds . . . . • . . . . 733 Irregular healing of operation wounds 739 Suppuration of wound after operations 74O Inflammation of the uvea after operations 74O Collapse of the cornea 744 CHAPTER II. Operations upon the Eyeball. Paracentesis of the cornea 746 Paracentesis of the sclera ; sclerotomy 747 Iridectomy 748 CONTENTS. XV PAGE Iridotomy 755 Discission of soft cataract 756 Discission of membranous cataract 759 Extraction of cataract 760 Simple linear extraction 760 Flap extraction . 761 Early operations for cataract 767 Depression 767 Keclination . 767 Daviel's operation . 768 Beer's operation 768 The operations of Von Graefe and others ...... 768 Erythropsia 771 CHAPTER III. Operations upon the Adnexa Bulbi. Squint operations ; tenotomy and advancement 772 Enucleation of the eyeball 780 Artificial eye 783, 784 Exenteratio bulbi 784 Optico-ciliary neurotomy 785 Exenteration of the orbit 785 Operations for trichiasis 786 Canthoplasty 792 Tarsorrhaphy 793 Operations for entropion 795 Operations for ectropion 797 Blepharoplasty 798 Operations for ptosis 801 APPENDIX. Instruments used in Ophthalmolooy : Instruments for opening the eye and keeping it in place Instruments for operations upon the lids . Instruments for strabismus and enucleation Instruments for lachrymal stricture . Instruments for removing foreign bodies Tattooing needles Instruments for iridectomy and iridotomy Instruments for paracentesis and discission Instruments for cataract extraction Ophthalmoscopes Instruments for skiascopy . The ophthalmometer and keratoscope . The perimeter ..... Instruments for muscle-testing . 805 806 807 808 809 809 810 811 813 814 816 818 819 830 PAET I. EXAMINATIOI^ OF THE EYE. CHAPTER I. OBJECTIVE EXAMINATION OF THE EYES. 1. The examination of a patient's eyes is begun after establishing the history of the case. In making this examination too much stress can not be laid upon the necessity of proceeding systematically, since otherwise important matters can very readily be overlooked. We first examine the patient with regard to his general physical condition as well as with regard to the expression of his countenance, and then, in observing the eyes themselves, proceed gradually from the superficial parts — lids, conjunctiva, and cornea — to the deeper portions. In respect to the lids, there are to be considered their position and mobility, the breadth -of the fissure between them and their power of closing. The character of the skin lining the lids is examined, and especially at their margins, where pathological changes are most often found. Apart from the symptoms of inflammation, which are local- ized with especial frequency at the borders of the lids, the things that we must look for are whether the palpebral edges have not pos- sibly lost their sharply defined form and outline, whether the cilia are correctly placed, and also whether the puncta dip properly into the lacus lacrymalis. At the same time, we must not neglect to investi- gate the region of the tear sac. Should simple inspection disclose no alteration, it is yet often possible, by pressure with the fingers in this region, to make the contents of the diseased sac exude through the puncta. The examination of the eyeball itself is often rendered very diffi- cult by strong spasm of the lids — blepharospasm. This is especially the case in children who, the more the physician attempts to draw the lids apart, squeeze them the more tightly together. In these cases the forcible separation of the lids calls for the greatest caution, since, if this is not observed, and a deeply penetrating ulcer is present, it is easy to cause a sudden perforation of the cornea, nay, even the extrusion of the lens from the eye. By dropping a solution of cocaine between the 1 1 2 EXAMINATION OF THE EYE. slightly parted lids we try to diminish their sensitiveness ; and for th& separation of the lids we can, with advantage, use Desmarre's elevator, with which we shall less readily inflict an injury than we should do if,, in using the fingers, we exerted too great a pressure upon the eyeball. Finally, in many cases it is only by means of narcosis that we can ob- tain a sufficiently satisfactory view of the eyes. In spite of all these difficulties we should not be deterred from insisting upon an exact examination of the eyes at the patient's first visit, in order to establish the diagnosis and prognosis and to determine the treatment. In regard to the eyeball itself, we must first satisfy ourselves whether its situation in the orbit, its position in respect to the other eye, its size, and its mobility are normal or not. The conjunctiva of the lids can be brought into view by everting the latter. -With the lower lid, it is sufficient for this purpose to simply draw it down, while the patient is told at the same time to look up. With the upper lid, eversion requires a certain degree of skill, which must be obtained by practice. It is the more important to acquire this facility, since it is just the conjunctiva of the upper lid that generally affords the best evidence for the diagnosis of conjunctival diseases: the thickening of the conjunctiva, the uneven surface, the formation of cicatrices, which are characteristic of trachoma, are here most easily to be perceived. Further, the eversion of the upper lid is very fre- quently necessary for the removal of foreign bodies. In the examination of the cornea, besides a careful inspection (if need be, with a magnifier, such as that of Hartnack), there are two main artifices in use — examination of the corneal reflex and lateral illumination. To examine the corneal reflex signifies nothing more than to direct the eye in such a manner that the reflection of a window placed opposite it is visible upon the cornea (in Pig. 30 the image of four window panes is seen upon the upper and outer quad- rant of the cornea). By causing the eye to follow the movements of a finger held before it, the reflection is gradually brought upon different portions of the corneal surface, of whose curvature and smoothness we in this way obtain an impression. Lateral illumination consists in the concentration of light upon a certain portion of the cornea by means of a convex lens. This impor- tant method, although already employed by Himly, Mackenzie, and Sanson, was yet very little known formerly, and first obtained general currency through the efforts of Helmholtz. A light (candle or lamp) is placed beside and somewhat in front of the patient. Then, by the aid of a strong convex lens (of 15-30 D.), the rays are concentrated to a cone of light, whose apex is made to fall upon the portion of the cornea to be examined. This method is designated as focal illumina- tion, because the point to be illuminated is brought into the focus of the lens. This point stands out with special distinctness because, on OBJECTIVE EXAMINATION OP THE EYES. 3 the one hand, a great quantity of light is concentrated upon it, and because, on the other hand, the parts immediately surrounding it re- main almost completely in darkness. On this latter ground, lateral illumination gives the most advantageous result if in its application the room is darkened. By lateral illumination we can recognize opacities in the cornea which are perceptible in no other way. The iris, too, and the lens as well, can be examined in this way by vary- ing the depth to which the light is projected. By so doing we have not merely the advantage of getting very sharp images, but also, from the fact that we can at will vary the depth to which the apex of the conical sheaf of rays is projected, we get information as to the depth at which the changes that we observe are situated. A handier method of lateral illumination is furnished by the lamp of Priestley Smith. This carries in its center a small candle as a source of light ; a strong convex lens let into the side of the lamp serves for the pro- duction of the cone of light. In addition to the appearance of the cornea we have further to examine its sensitiveness, which is best done by touching it with the point of a thread. The anterior chamber must be examined more especially in respect to its depth — that is, whether it is shallower or deeper, as a whole, or whether possibly it is of unequal depth. Further, we look for any abnormal matters which may be present in the chamber, such as an exudate, blood, foreign bodies, etc. In the iris its color as well as the clearness of its markings must be observed. For the recognition of adhesions the instillation of atro- pine is often requisite. We inspect the active movements (reaction) of the iris as well as any passive movement that may be present (tremulousness of the iris in movements of the eyeball). In order to determine the reaction of the iris to light, we first cover the eye by holding the hand before it, and then see whether, upon suddenly re- moving the hand, the pupil contracts (direct reaction). Then we see if the pupil of the eye under examination reacts when the other eye is alternately illuminated and shaded (consensual reaction). To keep the eye still while being thus tested, the patient is directed to fix it upon some distant object. Furthermore, we must test the reaction of the pupil to convergence and accommodation. Lastly, we deter- mine whether the pupil is circular, of normal width, centrally placed, and of pure black hue. Of the lens we see under ordinary circumstances only the small section of the anterior surface, which lies free in the pupil. If we wish to examine the lens more extensively, we dilate the pupil with homatropine and use lateral illumination. As long as the lens is still transparent, the ophthalmoscope gives us the best conclusions in re- gard to its constitution. Whether the lens is present in the eye at 4 EXAMINATION OF THE BYE. all or not can be determined by investigating the Purkinje-Sanson re- flex images. If a candle is placed before the eye and somewhat to one side of it, two brilliant reflections are observed. One of these at once attracts our attention by its size and brilliancy ; it is the corneal reflex — that is, the erect image of the flame reflected from the anterior sur- face of the cornea (Fig. 1, a). It is this re- flex which even from a distance is visible in every eye, and gives to the latter its fire and luster. The second reflex is quite as bright, but so small that we have to search for it in order to find it. It presents the very small inverted image of the flame which is reflected from the posterior surface of thei lens (pos- terior lenticular reflex. Fig. 1, c). It is dis- tinguished by moving in the contrary sense Fig. i.-purkinje-sanson's Re- to the sourcc of light whcn the position of FLEX Images. ° ■*■ , The black circle represeEts the the latter is shifted ; if the candle IS de- S^l^|tS.'Th?c'aa'fltL'I pressed, the shining point rises, and vice to^b^ser^i's^'eye^toVeie^^^ ^ersa, in opposition to the Corneal reflex, of the pupil, a, image formed which moves in the Same sense as the candle by the anterior surface of the cornea. 6, image formed by flame. It is this posterior lenticular image lens, c, image formed by the that is used in doubtf ul cases to demonstrate posterior surface of the lens. r ,i ■, ..i xj!n the presence of the lens in the eye. If the image is visible, the lens is present ; if the image is not seen, either the lens is absent from its place or else is more or less opaque, so that a reflection can no longer be developed on its posterior surface. (Fig. 1 also shows a third reflex image, S, placed between the other two and originating from the anterior surface of the lens. The latter gives an erect image larger than the others, but so faint that it can be made out only with difficulty.) Finally, before proceeding to an examination with the ophthalmo- scope, the tension of the eye is to be tested. The eye is closed and pal- pation is made by means of the two index fingers, which are placed upon the upper lid. Here, as in all the previously mentioned methods of examination, the best measure for any variation from the normal is obtained by a comparison with the other eye, it being presupposed that the latter is healthy. Examination with the Ophthalmoscope (Ophthalmoscopy). 2. The invention of the ophthalmoscope by Helmholtz in the year 1851 was one of the most beneficent achievements in modern medi- cine. It has made the interior of the eye accessible to investigation ; blood-vessels and nerves, which in the rest of the body are exposed only by surgical manipulation, here lie unveiled before us and permit us to study their minutest variations. In ophthalmology, the ophthalmo- OBJECTIVE EXAMINATION OP THE EYES. 5 scope has produced a complete revolution, since it has thrown light into the dark region of what was formerly called black cataract, and has acquainted us with the manifold morbid processes which lie at the root of this dreaded malady. Many of these processes, if diagnosti- cated correctly and in time, would, at the present day, receive success- ful treatment. Furthermore, in general medicine the ophthalmoscope has become an indispensable aid to diagnosis, since many internal dis- orders produce characteristic changes in the fundus of the eye. Principle of the Ophthalmoscope. — In order to see the fundus of an eye, we must throw light by the aid of suitable apparatus through the pupil and upon the fundus, and receive the light reflected from the latter into our own eye and unite the rays to form a sharp image. In the original ophthalmoscope of Helmholtz this end was obtained in the following way: Before the eye under investigation {A, Pig. 2) a glass plate, P F, is placed in an oblique position. A source of light, L, placed to one side of the eye, throws upon the glass plate rays, part of which are reflected at the surface of the plate and pass through the pupil into the eye, A. The rays reflected from the fundus, a, arrive once more at the glass plate and are there in part reflected to the source of light, L, while another part goes through the glass plate and Fio. 2.— Principle of Helmholtz's Ophthalmoscope. enters the observer's eye, B, which unites the rays upon its retina into a well-defined image, b. In order to increase reflection at the sur- face of the plate and thereby illuminate the background of the eye more intensely, Helmholtz placed three such plates one behind the other. A later modification consisted in increasing the reflecting power of the glass plate by lining its posterior surface with a mirror coating, a round hole through the plate or at least through the mirror coating enabling the observer to see through it. Of this sort are the coated plane mirrors, or mirrors of feeble illumination which are now 6 EXAMINATION OP THE EYE. employed. As mirrors of strong illumination we designate concave mirrors, which are also coated and are perforated through the center (first employed by Euete). These, from the fact that they render con- vergent the rays springing from the source of light, throw a still greater quantity of light throTigh the pupil into the observed eye. An apparatus is placed on the posterior surface of the mirror, which renders it possible to bring different sorts of lenses before the aperture. In this way it is possible to give the rays of light which fall into the observer's eye any path that may be necessary in order to unite them into a sharp image upon the retina. Method of Examination. — The examination is conducted in a dark- ened room. The patient sits opposite the physician, and has on the side of the eye to be investigated a lamp as a source of light. Then there are two different methods to be employed for seeing clearly the fundus of the eye. In order to make the explanation of them simpler, we first presuppose that both the patient and the physician have a normal refraction (emmetropia, see § 137). In the examination with the erect image {direct method), the physician places himself and his mirror directly in front of the eye that he is observing. If now he holds the mirror obliquely in such a manner that he throws the light of the lamp into the pupil of the observed eye, he will immediately get a clear Fig. 3.— Ophthalmoscopic Examination with the Erect Image. The eyes are drawn ot the natural size of an emmetropic eye having an axial length of 24 mm ^n^rtKfthlt%'S^?|??ro^LThe*^ltSr ^' ^ ^' ""° '""^ ''^^ ""^'^ ^^« "« ""' ^'>°™ ""* view of the patient's fundus. For (Fig. 3) a certain portion of the fundus of the eye. A, is illuminated by the mirror, S S. The rays re- flected from any point, as a of this illuminated region of the retina, leave the eye in a parallel direction, pass through the central aperture of the mirror, and fall into the observer's eye, B. Here they are again united at a single point, I, upon the retina of this eye, so that here there is produced a sharp image of the point a. Since the same pro- OBJECTIVE EXAMINATION OP THE BYES. 7 ■cess is repeated for all the other points of the illuminated region of the retina of the eye, A, a sharp image of this portion of the retina is formed in the eye of the observer. The examination with the inverted image, or by means of the in- direct method (Euete), is conducted with the aid of a strong convex lens of about six cm. focus. This lens, L (Fig. 4), is held at a distance of about six cm. from the eye (A) under examination. The fundus of Fig. 4. — Ophthalmoscopic Examination with the Inverted Image. ■The illummation of the fundus is accomplished by means of the source of light, L, from which the cone of rays, fc, falls upon the mirror, ,S 5, and from this is thrown into the eye, A. In order not to confuse the representation, these rays are not shown, but only those ■which pass out of the eye, Ay again. this eye is now illuminated by means of the mirror S S. The rays reflected from the illuminated region, a, of the retina pass out in a par- allel direction, fall upon the lens and are united at the focus,/, of the latter. Thus there is formed at this spot an image of the point a. In like manner images from the other points of the illuminated region of the retina are produced in the focal plane of the lens, so that there is formed here an inverted image of this portion of the fundus. The observer's eye, £, now through the aperture, 0, of the mirror examines this image at the ordinary reading distance (about thirty cm.), for which purpose the observer, unless he is myopic, must use a certain accommodative effort, or else a corresponding convex glass. Each of these two methods has its advantages. The erect image is highly magnified — about fourteen times — as opposed to the inverted image, which is magnified but little (about four times). The direct method is therefore particularly adapted for the recognition of the finer details. The indirect method, on the other hand, affords a larger field of view, and therefore gives a better general prospect. The indi- rect method gives a more luminous image, and hence, when the re- fracting media are turbid, will still render the fundus visible when it is no longer to be seen in the direct image ; and in myopia of high degree 8 EXAMINATION OF THE EYE. the indirect method is the only one practicable. In most cases, both methods are applicable, and then it is advisable to conduct the exam- ination with the aid of both. Luminosity of the Pupil.— Under ordinary circumstances the pupil ap- pears black. This was formerly ascribed to the absorption by the dark back- ground of the eye of all the light entering the pupil from the outside. In reality, however, the cause of this phenomenon is as follows : If (Fig. 5) light Fig. 5,— Path of the Rays when the Eye is focused for the Source of Light. from a source of light, L, enters the eye, A, and the latter is accurately focused for the source of light, the rays coming from L are united to form a sharp image upon the retina at I. L and I are called conjugate foci. For these the law holds good that they can be substituted for each other — ^that is, if the rays should start from the posterior focus, I, they would come together again at the anterior focus, L. Accordingly, the rays reflected from the illuminated portion of the retina, I, are returned to the source of light, L, and could be seen by an observer only in case the latter was in identically the same spot as the source of light. The solution of this problem is another of the ingenious dis- coveries of Helmholtz. The conditions are different when the eye is not focused for the source of light before it. Suppose, for example, that the eye is hypermetropic (Fig. 6). Then the rays springing from the illuminated portion of the retina, I, leave ■Explanation of Luminosity of the Eye. The source of light, L, throws the conical beam of rays, fc, into the eye. The further course of these rays is not shown in the figure, but only that of the rays reflected from the retina at I. the eye as a divergent beam, so that only a part of the rays are returned to the source of light, L, while another part passes to the side of the latter and can be seen by an observer stationed near it. Hence comes the striking lumi- nosity of the pupil in so-called amaurotic cat's eye (see § 99), in which a mark- edly hypermetropic condition of the refraction is produced by the pushing OBJECTIVE EXAMINATION OP THE EYES. 9 forward of the retina. In like manner, luminosity is frequently apparent in eyes which are deprived of their lens by the operation for cataract and are there- fore strongly hypermetropic. Moreover, the enlargement of the pupil, which is at the same time present, and which is due to the iridectomy, renders it still easier to observe the luminosity. The luminosity of the eyes of many beasts, especially the carnivora, is also in part to be ascribed to the hypermetropic character of their refraction, although here the presence of a strongly reflect- ing layer (the so-called tapetum) in the chorioid of these eyes contributes to this result. The luminosity of the pupils of albinos' eyes is to be explained in a differ- ent way. In such eyes the light passes not only through the pupil, but also through the unpigmented iris, and ev.en through the sclera. Accordingly, in these eyes, not simply a limited district of the retina, but the whole fundus, is flooded with diffused light ; and therefore rays from the different portions of the fundus pass out of the pupil in every direction and can very readily be caught up by the observer's eye. That this explanation is the correct one is proved by the fact that the pupil of an albino's eye looks black as soon as we hold before the eye a screen having an aperture that corresponds in size to the pupil. This shuts off from the eye any light which might enter it through other media than the pupil, and in this respect makes the eye of an albino like that of a normal person. 3. Application of the Ophthalmoscope.— In the ophthalmoscopic examination of the eye we invariably proceed by carefully investigating the eye by means of lateral illumination first, next testing the trans- parency of the refracting media with the ophthalmoscope, and not going on to the examination of the fundus itself until last of all. This last examination is best made first with the inverted, afterward with the erect image ; and in examining the latter the refraction can be de- termined at the same time. If the pupil is narrow, the tyro will do well to dilate it with cocaine or homatropine. Before doing so he must make sure that there is no reason to suspect glaucoma, in which case artificial dilatation of the pupil might have dangerous results, and therefore must not be employed. For testing the transparency of the refracting media light is thrown by the ophthalmoscope, held at the ordinary reading distance, into the eye under examination. If the refracting media are perfectly clear, the pupil shines with a uniform red luster. If there are places in the refracting media that are opaque, such stand out upon the red back- ground of the illuminated pupil as dark points or spots. For example, the rays which correspond to the opaque spot t (Fig. 7) are cut off on their return from the fundus, a, so that this spot is not illuminated and hence looks black. This is the case even when the opacities are actually, as seen by light thrown directly upon them, light colored— that is, white or gray. So also even a piece of chalk looks black if it is held in front of a flame. In making a systematic examination of the fundus we begin at the papilla. In order to bring the latter into view at once, we make the 10 EXAMINATION OP THE EYE. patient look, not straight in front of him, but a little inward (toward his nose). For the entrance of the optic nerve does not lie at the posterior pole of the eye, but on the nasal side of it, and hence is Fig. 7, — Visibility of Opacities in the Media by Means op the Ophthalmoscope. brought directly opposite the observer only after a corresponding rota- tion of the eye inward. It then comes into view as a bright disk, whose color is a light grayish or yellowish red, contrasting strangely with the red of the rest of the fundus (Fig. 8). The shape of the papilla is circular or oval ; in the latter case generally an erect oval. Its size apparently varies quite a good deal, which, however, is due to the varying degree of enlargement under which the papilla is seen. The true size of the papilla, measured in enucleated eyes, is, as a matter of fact, almost always the same — that is, about 1.5 mm. in diameter. On account of this constancy we use the papilla for taking measurements in the fundus ; we say, for example, that a diseased area is 2 papilla- breadths in diameter. Circumscribing the papilla, we very often (especially in making the examination with the erect image) recognize two rings distinct in color. The inner ring, lying next the border of the papilla, is white (Fig. 9 A between c and d; see also Pigs. 8 and 11), and is called the scleral ring, because it owes its white color to the fact that the sclera is here exposed to view. It is present when the canal in the sclera, through which the optic nerve passes, is narrowest, not as is often the case, at its anterior orifice, but somewhat farther back, so that the foremost portion of the canal forms a funnel with the base forward. The wall of this funnel, which is formed of white sclera (Fig. 9 £ between c and d), appears when seen with the ophthalmoscope in perspective foreshort- ening, as a narrow white ring. At the margin of the aperture in the chorioid that gives passage to the optic nerve, the chorioid is often marked by a larger accumulation of pigment, by which the second, ex- terior ring is formed. This is apparent as a black, narrow, sometimes complete, sometimes incomplete, ring, which is designated as the chorioidal ring or pigment ring (Fig. 9, d, and Fig. 8, where it is visi- ble especially at the outer border of the papilla). OBJECTIVE EXAMINATION OF THE EYES. 11 The demarcation of the outline of the papilla, produced in this way, is generally much less sharp on the nasal than on the temporal side ; for at the nasal side a greater number of nerve fibers pass over the margin of the papilla and thus obscure it. For the same reason the inner half of the papilla looks redder, the outer half paler, because the layer of nerve fibers in the latter situation being thinner, allows the lamina cribrosa to show through more. The optic disk under normal conditions lies in the plane of the retina, and does not therefore form a projection upon it as the name papilla would lead one to suppose. On the contrary, it very frequently contains in its center a depression, which is produced by the fibers of the optic nerve separating from each other comparatively early and thus leaving a funnel-shaped' space between them (vascular funnel, natal ^^1 f temporal Fig. 8. — Normal Fundus of the Left Eye, seen in the Erect Image. The optic disk, which is somewhat oval longitudinally, has the point of entrance of the central vessels somewhat to the inner side of its center. That portion of the papilla lying to the inner side of the point of entrance of the vessels is of darker hue than the outer portion ; the latter shows, directly to the outside of the vascular entrance, a spot of lighter color, the physiological excavation with fine grayish stippling, representing the lacunae of the lamina cribrosa. The papilla is surrounded, first by a light-colored ring, the scleral ring, and exter- nally to this by an irregular black stripe, the chorioidal ring, which is especially well marked on the temporal side. The central artery and vein divide immediately after their entrance into the eye into an ascending and descending branch. These branches, while still on the papilla, split into a number of smaller divisions, and fine offshoots from them run from all directions toward the macula lutea, which itself is devoid of vessels, and is distinguished by its darker color. In its center a bright punctate reflex, /, is visible. Pig. 9 B, I). The central vessels ascend on the inner wall of the fun- nel. The color of the vascular funnel seems white to us because we see the white lamina cribrosa at its bottom. Often, instead of a small funnel-shaped depression, a large excavation {physiological excavation) is present. This is situated in the outer half of the papilla, to whose external border it often reaches. The blood-vessels come out upon the inner border of the excavation (Pig. 8), and at the bottom of the latter are seen grayish dots, the lacunse of the lamina cribrosa. With the brilliant white of the excavated exterior half of the papilla the grayish- 12 EXAMINATION OP THE EYE. red hue of the unexcavated interior half is in vivid contrast. Some- times the physiological excavation is so large that it takes in the larger B Fig. 9.— Head of the Optic Nerve. A^ Ophthalmoscopic View.— Somewhat to the inner side of the center of the papilla the cen- tral artery rises from below, and to the temporal side of it rises the central vein. To the temporal side of the latter lies the small physiological excavation with the gray stippling of the lamina cribrosa. The papilla is tncircled by tne light scleral ring (between c and d), and the dark chorioidal ring at d. B, Longitudinal Section through the Head op the Optic Nerve.— Magnified 14 x 1. The trunk of the nerve up to the lamina cribrosa consists of meduUated nerve fibers, n. The clear interspaces, se, separating them, correspond to the septa composed of connective tissue. The nerve trunk is enveloped by the sheath of pia mater, p, the arachnoid sheath, m\ and the sheath of dura mater, du. There is a free interspace remaining between the sheaths, consisting of the subdural space, sd^ and the subarachnoid space, sa. Both spaces have a blind ending in the sclera at e. The sheath of dura mater passes into the external layers, sa, of the sclera, the sheath of pia mater into the internal layers, si, which latter extend as the lamina cribrosa transversely across the course of the optic nerve. The nerve is represented in front of the lamina as of light color, because here it consists of non-medul- lated and hence transparent nerve fibers. The optic nerve spreads out upon the retina, r, in such a way that in its center there is produced a funnel-shaped depression, the vascular funnel, 6, on whose inner wall the central artery, a, and the central vein, v, ascend. The chorioid. c7i, shows a transverse section of its numerous blood-vessels, and toward the retina a dark line, the pigment epithelium ; next the margin of the foramen for the optic nerve and corresponding to the situation of the chorioidal ring, the chorioid is more darkly pig- mented, ci is a posterior short ciliary artery which reaches the chorioid through the sclera. The posterior portion of the scleral canal forms a funnel directed backward, the anterior portion a funnel directed forward. The wall of the anterior funnel when seen from in front appears to have the extent, cd, and corresponds to the scleral ring visible by the ophthal- moscope. part of the papilla, but it never takes in the whole ; there is always a part (though it may be a small part) of the papilla that escapes it. By this circumstance the physiological is distinguished from the pathologi- OBJECTIVE EXAMINATION OP THE EYES. I3 cal excavation, which affects the entire papilla (total excavation, cf. § 81). The central vessels of the optic nerve divide at the head of the nerve into a number of larger and smaller branches, which pass over its edge into the retina, where they keep on branching after the fashion of a tree trunk. They can readily be distinguished into arteries and veins. The former are of a brighter red, narrower, and run a straight course (Figs. 8 and 9, a a) ; the latter are darker, of greater caliber, and more crooked (Figs. 8 and 9, v v). The arrangement of the vessels in the retina is not always the same ; most frequently it happens that two main branches run upward and two downward, while only small and short twigs pass to the outer and inner sides of the disk (Fig. 8). The region of the macula lutea is devoid of larger vessels ; the larger trunks, running to the outside above and below, encircle it and send finer branches in toward it. In the larger vessels we notice a shining white streak running along the center of the vessels. This streak, which is more distinctly visible in the arteries (Fig. 9 A, a a) than in the veins {v v), is called the reflex streak (Jager). A pulsation is frequently observed in the vessels at the spot where they first come to view upon the papilla. A venous pulse is a physio- logical occurrence : in the same eye it is sometimes present, sometimes absent. In the latter case, slight pressure upon the eye with the finger suffices to produce it. Bonders gives the following explanation of the venous pulse : At each systole of the heart an additional quantity of blood is driven into the arteries of the interior of the eye, and the blood pressure in these arteries is consequently heightened. This increase in the arterial ten- sion reacts at once upon the general intra-ocular tension, heightening the latter, so that it acts more vigorously upon the retinal veins and compresses them. It does this most at the spot where the blood pres- sure in the veins is lowest, which is at their point of emergence upon the papilla, since the blood pressure in the veins diminishes in propor- tion as we approach the heart and get farther away from the capillaries. The veins consequently are constricted at the spot where they dip down into the vascular funnel, while the portion of the veins directly ad- jacent swells up, because the blood is dammed up in it. But as a result of this damming, the blood pressure in the veins rises rapidly to the point where it is able to overcome the compression— doing this the more readily as now the diastole of the heart sets in, and with this the intra-ocular pressure diminishes. An arterial pulse is present under pathological conditions only. In order to produce it artificially in a healthy eye, no inconsiderable pressure must be exerted upon the eyeball. When this is done, the person under examination notices a simultaneous obscuration of the 14 EXAMINATION OF THE EYE. field of vision, amounting finally to complete abrogation of sight, as a result of the obstruction to the retinal circulation produced by the pressure. In like manner a rise in pressure produced by pathological conditions (glaucoma) causes an arterial pulsation. The explanation of this is as follows : As a result of the increased pressure in the interior of the eye, the blood is able to enter the vessels of the retina only dur- ing the systole of the heart ; during the diastole, when the pressure in the arteries becomes somewhat lower, the latter are occluded by the intra-ocular pressure. Such a disproportion between the intra-ocular pressure and the pressure of the blood in the central artery may also, of course, be produced by the fact that while the former remains nor- mal, the latter is diminished. Accordingly, an arterial pulsation is observed in general anaemia and when syncope is imminent ; also in local compression of the central artery within the optic nerve (e. g., in optic neuritis). Lastly, in some cases — e. g., in insufficiency of the aortic valves and in Basedow's disease — the presence of an arterial pulse in the eye is but one of the symptoms of an abnormally extended dif- fusion of the pulse wave in all parts of the body. Since in healthy living eyes the retina is transparent, we see no part of it with the ophthalmoscope except the blood-vessels. At most we find the red fundus in the immediate neighborhood of the papilla covered by a delicate gray veil which shows a radiating fine striation and which is the representative of the layer of nerve fibers of the retina, which in this situation is still quite pronounced. In children vivid reflexes often exist which are especially pronounced along the vessels, change their place with every movement of the mirror, and give the retina a luster like that of watered silk. We must avoid re- garding these as pathological opacities of the retina. The region of the retina that is most important for vision, the macula lutea, with the fovea centralis, is Just the part that has very few distinctive ophthalmoscopic features. We find it with the ophthalmoscope, if we go a distance of 1| to 3 diameters of the papilla outward from the outer border of the papilla. Here we come upon a region devoid of vessels which is somewhat darker than the rest of the fundus. Di- rectly in its center, corresponding to the situation of the fovea cen- tralis, we see a bright point or a small, crescentic spot (Pig. 8, /). In the inverted image the macula lutea is represented by a fine white line which forms a horizontal oval of about the size of the papilla. The region inclosed by the line is colored a dark brownish red and sometimes has in its center a little bright dot. These appearances are nothing more than reflexes produced by the light on the inner surface of the retina, and are by no means constantly present. When the pupil is dilated they become less marked or disappear altogether. The red background on which the appearances above described are visible is made by the chorioid. This owes its red color to the OBJECTIVE EXAMINATION OP THE EYES. 15 blood circulating in the chorioidal vessels, and especially in the capil- laries. That the individual vessels are not themselves recognized, that on the contrary the fundus appears uniformly red, is due to the fact that the pigment epithelium covers the chorioid like a murky veil. The pigment epithelium, too, has a marked effect upon the brightness of the red color of the fundus. In very dark-hued men the pigment epithelium scarcely allows the red of the chorioid to shine through, so that the fundus appears almost dark gray. The less pigmented the person is, the brighter the red of the fundus. In such cases a finely Fie. 10.— Tessellated Fundus. (For the alteration of the papilla here depicted, which is due to congenital malformation, see the description attached to Fig. 111.) granular condition of the chorioid is often perceived in the erect image, which is caused by the cells of the pigment epithelium. Under certain circumstances, however, the vessels also of the chori- oid are visible. We observe this chiefly under two conditions, viz. : (1) In many eyes the interspaces between the chorioidal vessels (the so-called intervascular spaces) have an especially profuse pigmen- tation, so that they stand out as dark elongated islands ; the bright-red striae running between them and anastomosing everywhere with each other, correspond to the chorioidal vessels which are chiefly veins. Such a fundus is said to be tessellated (Pig. 10) ;, it is often confounded with chorioiditis by beginners. (3) In other eyes, on the contrary, it is the abnormally scanty pigmentation of the fundus that permits the vascular system of the chorioid to be seen; the epithelial layer, on account of the unduly 16 EXAMINATION OF THE BYE. small amount of pigment which it contains, allowing the chorioidal vessels to appear through it. This is in the greatest degree the case in albinos, who are entirely devoid of pigment. In these the whole net- work of chorioidal vessels down to the most delicate ramification stands Fig. 11.— FnNDUB of as Albinotio Ete seen in the Erect Image. (After Jager.) The papilla Ls surrounded by a light-colored scleral ring, and looks dark in comparison with the light hue of the rest of the fundus. The latter shows a thick network of chorioidal vessels and over them the retinal vessels, which are distinguished from the former by their better defined outline, their narrow caliber, and their tortuous course. Both the chorioidal and retinal vessels contrast by their darker red with the very light red of the background, the line of which is formed by the white sclera shining through the chorio-capillaris. It is only at the macula hitea that the somewhat darker hue of the fundus gives evidence of the presence of a slight pigmentation of the chorioid. out upon the pale-red background (Fig. 11). The retinal vessels run over the chorioidal vessels, but are easy to distinguish from them. The chorioidal vessels are broader, less sharply defined, and look flat and ribbonlike; they lack the reflex streak. In opposition to the retinal vessels, which branch after the manner of a tree and do not anastomose, they form by their numerous anastomoses a dense network with elongated meshes. Examination of the Kepr acting Media. — For this purpose, when pro- nounced opacities are present, we make use of the concave mirror ; slight opacities, on the other hand, are discovered only by means of the mirror of feeble illumination (plane mirror) ; and in this case it is often also necessary to dilate the pupil with homatropine. If the observer is emmetropic, and still more if he is hypermetropic, he ought to place a convex glass behind his mirror, so as to be able to get near enough to the eye that he is examining and still see with distinctness. A myopic observer will not need such a glass. In examining, we must not neglect to make the eye move in different directions, in order, on the one hand, to obtain a view of laterally placed opacities, and, on OBJECTIVE EXAMINATION OF THE EYES. 17 the other hand, to stir up in this way opacities which have sunk to the bottom of the vitreous humor. Smaller opacities look black ; larger opacities appear gray or even white, since the light reilected from their surface is strong enough to shine out upon the vivid red background of the illuminated pupil. In order to recognize the site of the opacity, we decide, in the first place, whether the latter is movable or fixed. In the former case it can be situated only in the vitreous; in the latter case— that is, if the opacity moves only with the eye, and not spontaneously — it is probably situated in the cornea or in the lens; but it may still be in the vitreous, since here too fixed opacities are sometimes observed. In many cases this can be decided by employing lateral illumina- tion. If we can obtain no result in this way, we then, in order to determine the site of the opacity, make use of the iiamllactic d splacement of the latter with reference to the margin of the pupil. 'J'his is accomplished in the follow- ing way: In the e^-e, A (Fig. 12), suppose four opaque points to be present, which lie at different depths — namely, in the cornea (1), upon the anterior cap- sule of the lens (2), at the posterior pole of the lens (3), and in the anterior part of the vitreous (4). For simplicity's sake we assume that they are all dis- posed in the optical axis of the eye. Then, if the observer, B, looks into the eye from directly in front, he will see each one of these points precisely in the center of the pupil, P. Suppose, now, that the observer's eye passes from B to Bi. The position of the points with relation to the jiupil will be changed at once. Point 1 approximates to the upper border of the pupil P, ; point 2, which is situated in the pupil itself, keeps its place unchanged ; points 3 and 4 have approached the lower border of the pupil ; and 4, on account of its greater Fig. 18.— Diagnosis of the Site of an Opacity from Parallactic Displacement. depth in the eye, more so than 3. From this example the following rule for the determination of the site of an opacity can be deduced : We look into the eye from directly in front and note the position of the opacity in the pupil. Then, while the patient holds his eye fixed, we move slowly to one side and observe whether the opacity remains in the same spot or not. In the former case, the opacity lies in the pupillary plane (upon or directly beneath the anterior capsule of the lens) ; in the latter case, in front of or behind this plane —in front of it, if the opacity shifts its place with a movement opposed to that 2 18 EXAMINATION OF THE EYE. of the investigating eye ; behind it, if the opacity moves in the same sense as the eye. The more quickly this change of place occurs, the farther removed is the opacity from the pupillary plane. (Evidently we can also proceed by keep- ing our own eye still and telling the patient to move his. This way of exam- ining has the disadvantage that, if the movement of the observed eye is rather extensive, a minute opacity, whose position has been marked, may disappear out of sight and then frequently is found again only with difficulty.) Dark, ill-defined shadows on the red background of the pupil, which change their position suddenly on moving the mirror, are to be referred to irregulari- ties of the refracting surfaces (most frequently to faceting of the cornea) ; the irregular astigmatism so caused further betrays itself by the fact that the image of the fundus appears irregularly distorted. Determination of the Refraction.' — The determination of the refrac- tion by the ophthalmoscope may be accomplished in three ways : with the erect image, with the inverted image, and by the shadow test. (1) Determination of the refraction with the erect image. When the eye under examination is emmetropic, the rays emitted from the illuminated retina emerge parallel to each other (as shown in Fig. 3) ; hence the observer's eye, which in all that follows we shall assume to be emmetropic, can without exer- cising any accommodation unite them into a sharp image. Emmetropia, how- ever, represents the only condition of the patient's eye in which an emmetropic observer can without ulterior aid see distinctly the patient's fundus ; when the patient's refraction is of any other nature, the observer, to see clearly, must use either a glass or his accommodation. Suppose the eye to be examined {A, Fig. 13) to be myopic, with its far point at F so that the rays coming from i?" are united on the retina aty (see § 143). FiQ. 13.— Correction of Myopia by a Concave Lens. The eye is drawn of the natural size of a myopic eye having an axial length of 27 mm. FmA/are conjugate foci, and the course of the rays would therefore be the same if they should proceed in the opposite direction— i. e., from /toward F; in that case, they would be united at F, as they emerge from the eye. A point/ of the retina, illuminated by the ophthalmoscope, will then emit a bundle of rays con- verging at F; and at this distance there is produced a clear image of the illu- minated fundus. The observer's eye, which is placed at a short distance (a few centimetres) from the eye A, would catch the rays emitted from the latter before they were united at -f— that is, while they still had a certain amount of OBJECTIVE EXAMINATION OP THE EYES. 19 convergence. But the observer's eye, unless it were hypermetropic, is not in a position to unite convergent rays into a sharp image. If the eye is emmetropic, as we will assume it to be, the rays which fall upon it must first be made par- allel, which evidently is accomplished by a concave lens, L. Now, how is this lens related to the degree of myopia of the eye under investigation ? If we im- agine the course of the rays reversed, then parallel rays coming from in front and falling upon the lens L would be rendered by the latter so divergent that they would come to a focus upon the retina of the myopic eye; the myopic eye Fig. 14. — Correction op Hypebmetropia by a Convex Lens. The eye is drawn of the natural size of a hypermetropic eye having an axial length of 21 mm. accordingly would get sharp vision with this lens for parallel rays — that is, rays coming from an infinite distance. L would therefore be the correcting glass for the myopia of the eye, A. We can hence say this : In order that an emmetro- pic observer should see clearly the fundus of the myopic eye, A, he must use the same glass that will correct the myopia of this eye. If, therefore, an em- metropic observer has to determine the refraction of a myopic eye with the ophthalmoscope, he keeps placing concave glasses before it until he finds one with which he gets a sharp view of the fundus in the erect image ; the glass employed gives directly the degree of the myopia. The same principle holds good for hypermetropic eyes, only that convex instead of concave glasses are required. The rays emitted "from the hypermetropic eye, A (Fig. 14), are divergent, and the more so the higher the hypermetropia is. The convex glass, X, which is required in a given case of hypermetropia in order to render par- allel the divergent rays emerging from the eye and thus make it possible for the emmetropic observer to perceive the fundus, is the same as that which ren- ders rays falling upon the eye in a parallel direction so convergent that they are united upon the retina, and is therefore the glass which corrects the hyper- metropia. Hence the degree of hypermetropia of the eye under examination is given immediately by the convex lens with which the emmetropic observer sees the fundus distinctly. An emmetropic observer can also, it must be noted, cause divergent rays to focus upon his retina by calling his accommodation into play, and in this way can see the fundus of a hypermetropic eye distinctly even without the aid of a convex glass. But as one can not estimate precisely the degree of accommo- dation thus applied, it is impossible to determine the amount of hypermetropia with precision by proceeding in this way. How is it in those cases in which the physician himself is not emmetropic ? 20 EXAMINATION' OF THE BYE. In that case he must simply correct in addition his own ametropia ? If, for instance, an emmetrope is examining an eye having a myopia of 3 D, he needs for this purpose — 2D. If the observer himself should have a myopia of 3 D, he would have to take in addition — 3 D for himself ; hence he would employ a glass of — 5 D. If the observer were a hypermetrope of 1 D, he would need + 1 D for the correction of his own ametropia ; this, in combination with the — 2D which are required for the eye under examination, gives a lens of — 1 D. A similar procedure must be adopted in those frequently occurring cases in which the observer is indeed emmetropic, but can not completely relax his accommodation during the ophthalmoscopic examination. He is then to be regarded as a myope, inasmuch as he has to neutralize his residual accommo- dation by a corresponding concave glass. (2) The determination of the refraction with the aid of the inverted image is done by the method proposed by Schmidt-Rimpler, the principle of which is as follows : The concave mirror, 8 S (Fig. 4), forms at its focus a sharp image of the flame that is used as the source of light in making the ophthalmo- scopic examination. This image lies between the mirror and the convex lens (I). Rays emanating from it are by means of the lens thrown upon the retina of the patient's eye to form there a new image of the flame, which the observer sees upon the fundus. Whether this latter image is sharp or not depends upon various circumstances : upon the strength of the mirror and the lens; upon the distances between the lamp, the mirror, the lens, and the eye ; and lastly upon the refraction of the latter. By taking all these factors into con- sideration we can determine the refraction, provided we ascertain the distance at which the observer has to be in order to see the image of the flame upon the fundus of the patient's eye distinctly. For this purpose the apparatus devised by Schmidt-Rimpler is employed. (8) The determination of the refraction by means of the shadow test was discovered by Cuignet, who called it keratoscopy. It is also knovm as pupil- loscopy, retinoscopy, and skiascopy (o-Km, shadow). In using it, the observer places himself at a distance of rather more than one metre from the patient, and throws light into his pupil by means of a concave mirror. When the mirror is in a certain position, the whole pupil appears of a vivid red ; then if the mirror is turned a little on its vertical axis, a black shadow appears at the edge of the pupil and, as the mirror is rotated still more, passes over the whole area of the pupil, until the latter is completely dark. From the direction in which the shadow travels the refractive state of the eye under examination can be ascer- tained. To accomplish this, we must, to start with, have a clear comprehen- sion of the signiflcance of the illuminated portion of the pupil and of the shadow respectively. By means of the mirror a point of the fundus is illuminated, and from this point the rays are returned in such a way that a portion of them pass out again through the pupil. The direction which these rays take on emerging is deter- mined by the refraction of the eye. If myopia is present, we know that the emergent rays will converge so as to meet at the far point of the eye. In Fig. 15 let J P and Pi /, be the iris, and P P, the pupil of the patient's eye. The rays emerging from the pupil unite at the far point R of the eye. If we suppose that by means of the mirror a point of the retina is illuminated which lies somewhat to the right of the line connecting the pupillary centers of the observer's and of the patient's eyes, R will be situated correspondingly far to OBJECTIVE EXAMINATION OP THE EYES. 21 the left of this line. From S the rays (now become divergent) continue on their way toward the observer's eye, which we will now suppose to be beyond JR. i p and pi ii represent the iris, and p pi the pupil of this eye. Now p pi does not take in all of the conical sheaf of rays emanating from M, but only a por- tion of it, having ^ o as its base. The remainder of the cone falls upon the iris p i. Since the rays constituting this part of the cone are not seen by the observer, the portion of the pupil which is opposite to them, and from which they come (represented in Pig. 15 by the lines of shading), appears unillu- minated; the only portion of the pupil that does appear illuminated being that which is here shown as unshaded, and from which the observer receives rays that enter his own pupil. The dark and the luminous portions of the pa- tient's pupil are separated by a curved line, since the boundary between the two is formed by the pupillary edge p of the observer's eye. Thus the circle at the bottom of Pig. 15 represents the pupil of the patient's eye seen from in front ; the portion of it left unshaded in the figure corresponds to the illumi- nated part of the pupil. Now suppose that by a rotation of the mirror the spot of illumination in the fundus shifts in such a way that R travels farther to the left. Then more and more of the emergent beam will fall upon the iris, and less and less of it will fall upon the pupil of the ob- server's eye, and the shadow in the pupil of the patient's eye will, as the arrow in the circle indicates, advance farther and farther toward the left pu- pillary margin, until finally the whole pupil appears dark. The shadow, therefore, moves in the same direction that B does. We have now to determine how the movements of R are related to the movements of the mirror. If a concave mirror is employed, it forms at its focus an image of the lamp flame which lies between the mirror and the pa- tient's eye and serves to illuminate the latter. If the mirror is rotated to the left, the image of the flame also travels to the left. But as the portion of retina illuminated must always lie on the side diametrically opposite to the body that illuminates it — namely, the image of the flame — it must, with the movements of the mirror, move in a sense opposed to that of the image of the flame— i. e., to the right (from B or Bi in Fig. 15). But the point of union, R, of the emergent rays lies diametrically opposite to that occupied by the illumi- FlG. 15. -Shadow Test in Myopia. 22 EXAMINATION OP THE EYE. nated portion of the retina ; hence R will move to the left— i. e., in the same direction as the mirror. Now since B moves to the left when the mirror is ro- tated to the left, and as the shadow in the pupil travels to the left when B, moves to the left, we may say. When a concave mirror is used the shadow in the patiemfs pupil moves in the same sense as that in which the mirror rotates, provided the far point of the patienfs eye lies ietween the ohserver''s eye and the mirror. These relations are reversed when we come to examine a myopic eye whose far point is beyond the observer's eye. By constructing Fig. 15 so that R lies beyond i p, it will be found that in this case the illuminated portion of the pupil lies on the right side, and that as R shifts to the left the shadow goes to the right. The like is true for those cases in which the far point of the patient's eye lies behind the latter, as is the case in hypermetropia. This will be clear from Fig. 16. P Pi represents the pupil of a hypermetropic eye, from which the rays that emanate from the retina pass out, taking a diverg- ent course. They thus form a cone whose apex lies behind the eye at its far point, R. If the illuminated portion of the reti- na lies to the right of the line connecting the pupillary centers of the two eyes, E is also foimd to the right of the latter. The pupil, p pi of the observer's eye takes in only that part of the >conical sheaf of rays which corresponds to the right-hand por- tion of the patient's pupil (the portion left unshaded in the figure). The left-hand portion of the patient's pupil (represented by the lines of shading in the figure) re- mains unilluminated, because the rays that come out from it no longer fall upon the observer's pupil. The more R moves to the right, the more the unilluminated portion of the pupil is displaced to the right in the direction indicated by the arrow in the circle below. The shadow therefore, travels in the same direction that R does, as is also the case in myo- pia when the far point lies in front of the observer's eye (Fig. 15). The difier- ence between the two cases lies in the different relation that the movement of R has to the rotation of the mirror. If the concave mirror is rotated to the left, the image of the flame produced by it travels likewise to the left, and the spot of illumination upon the retina travels to the right (from B to Bi), Then i Fig. 16.— Shadow Test in Hypermetropia. OBJECTIVE EXAMINATION OF THE EYES. 23 the beam of rays retm-ning from this spot of illumination shifts to the left, but B, since in the hypermetropic eye it lies at the prolongation of these rays back- ward, moves to the right. B, therefore, moves in a direction opposite to that in which the mirror rotates, and the same is true of the pupillary shadow, which always moves in the same way that B does. Hence when a concave mirror is used, the shadow moves in a direction opposite to that in which the mirror is rotated, provided the far point of the patient's eye lies behind the observer's eye {in low degrees of myopia) or behind the patient's eye {in hypermetropid) . The way in which the shadow moves, therefore, depends upon the relative situation of the far point and the observer's eye. If the observer stations him- self at a distance of rather more than 1 m. (say 130 cm.) from the patient's eye, B lies between the two eyes when there is myopia of 1 D. or more, because then the patient's far point lies at 1 m. or less from his eye. In myopia amounting to less than 1 D. the far point lies behind the observer's eye, and the same is true of emmetropia, in which the far point lies at infinite distance. In hyper- metropia, on the other hand, the far point lies behind the patient's eye. From these facts are derived the following rules for conducting the shadow test : The observer, standing at rather more than 1 m. from the patient, illumi- nates the eye with a concave mirror, and notices the way in which the shadow moves in the patient's pupil as the mirror is rotated. If the shadow moves in the same direction that the mirror rotates, there is myopia of 1 D. or more. Then successively stronger concave glasses are set before the patient's eye in a trial frame * until a glass is found with which the shadow travels in the reverse direction. This glass carries the far point of the eye to just beyond 1 m. (cor- responding to a refractive power of 1 D.) ; and the last glass, n D., with which the shadow still moves in the same sense as the mirror, corrects the myopia of the patient's eye up to approximately 1 D. Hence the total myopia of this eye is 7iD-f-lD. If, when the mirror is rotated, a movement of the shadow takes place in the opposite direction, there is then in the eye that is being examined either myopia less than 1 D. , or emmetropia or hypermetropia. In this case a series of con- vex glasses is placed before the patient's eye until the shadow begins to move in the same direction as the mirror. If this glass is to D., the refraction of the patient's eye is w D — 1 D.^ The shadow test can also be conducted with the plane mirror. With this the image of the flame lies behind the mirror, and hence, when the latter is rotated, moves, not with the mirror, as is the case when this is concave, but in the opposite direction. Accordingly, the movement of the pupillary shadow with relation to the rotation of the mirror is just the reverse of that which obtains with the concave mirror.f * [Instead of placing a number of glasses one after another in a trial frame, we may also employ a revolving disk, a set of lorgnette frames, or an oblong slide in which a series of such glasses is permanently fixed after the fashion of an ophthal- moscope. Such an appliance, which is called a sTciascope, allows the glasses before the patient's eye to be rapidly shifted either by the patient himself or by the physi- cian, without the latter having to move from his station. — D.] f [I. e., the shadow moves in the opposite direction to that in which the mirror is rotated — moves to the right when the mirror is rotated to the left, or, as the phrase is, moves " against " the mirror in myopia of such a degree that the 24 EXAMINATION OP THE BYE. In either case this method is of great simplicity; of all methods it is the easiest to leam, and has the advantage that in it the refraction and accommoda- tion of the observer do not need to be considered. Withal it gives as exact results as any one of the other methods. A superficial estim-^te of the refraction of an eye can be got whenever an observer at some distance (say about the ordinary reading distance) from it is able to see portions of the fundus. This is the case both in marked myopia and in marked hypermetropia. In marked myopia the rays emanating from the eye come together in front of and very close to it at its focus F (Fig. 13), where, accordingly, an inverted image of the fundus is produced, and that without the aid of a convex glass. The observer can see this image if he places himself at a suitable distance— e. g., the ordinary reading distance. That it is an inverted image which he sees is obvious from the fact that it moves to the right when he moves his head and mirror to the left, and vice versa.* If the observer approaches the patient's eye, the image of the fundus rapidly becomes iBdistinct and soon disappears altogether, because the observer then gets so close to it that he can no longer accommodate for it. In marked hypermetropia, too, the image of the fundus can be seen at some distance from the eye, but in this case it is an erect image. It moves in the same direction that the observer moves, and remains distinct when the latter approaches the patient's eye. We can thus determine whether we are dealing with a high degree of myopia or of hypermetropia. The presence of regular astigmatism may be recognized from the change of shape which the papilla undergoes. In regular astigmatism one meridian of the dioptric system of the eye is more refractive than the one at right angles to it ; may be said, in fact, to correspond to a stronger convex lens than does the latter. Hence with the erect image the papilla will be seen under a greater enlargement in the more refractive meridian. If the latter, as is generally the case, is vertical, a round papilla will appear like a vertical oval. But the papilla often has in reality an oval form ; and, in order to distinguish whether we are dealing with a papilla that is anatomically oval or with an astigmatic distortion of a round papilla, we must resort to a comparison with the inverted image. If the papilla is really a vertical oval, it must appear so with the in- verted image also. If, however, there is astigmatism, the distortion due to it in the inverted image will be the opposite to that produced in the erect image — i. e., in the example given the papilla in the inverted image would appear trans- patient's far point is between him and the observer; and in all other eases — in less degrees of myopia, in emmetropia, and in hypermetropia — moves "with" the mirror. — D.] * [This is not so much an evidence of the image's being inverted as of its being in front of the eye. The image of the fundus, in fact, appears to move to the right when the observer moves his head to the left, because it lies in front of the plane of the pupil to which its movements are referred. On the other hand, in hyper- metropia the image of the fundus appears to move in the same way that the ob- server does, because the image then lies behind the plane of the pupil. The con- ditions are the same as when we are on a moving train and, looking out at the telegraph poles near the track, backed by trees in the distance, the trees appear to move in the same direction as the train, and the telegraph poles in the opposite direction, the movements of both being projected upon some plane intermediate between the two. — D.] OBJECTIVE EXAMINATION OP THE EYES. 25 versely oval. (This, however, is only the case when the convex lens used for forming the inverted image is held close to the patient's eye. If the lens is gradually carried ofi, the papilla appears first round, and finally a transverse oval.)* Detbkmination of DirFERBNCEs OF Lbvel in the Fundus.— Differences of level can not only be appreciated, but also precisely measured by means of the ophthalmoscope. This is effected with the aid of the erect image, by means of which the refraction can be determined for every point separately of the visible fundus. If a point in the fundus projects above its surroundings^ Fig. 17.— Parallactic Displacement of the Inverted Image of Points op the Fundus, LYING AT Different Levels. as, for instance, the swollen papilla in neuritis, the axis of the eye correspond- ing to this point is shorter — that is, there is a hypermetropia. By determining the degree of the hypermetropia we can compute the height of the prominence. Conversely, a point of the fundus which lies farther back (for example, the bottom of an excavation) possesses myopic refraction, from which the linear measure of the amount of depression can be found. As the basis of this com- putation the rule holds that a difference of level of about one millimetre cor- responds to a difference of refraction of 3 D. Differences of level of the fundus are also made apparent in the inverted image \>y parallactic, displacement. We proceed for this purpose by moving the convex lens which serves for the production of the inverted image a little up and down during the examination. If the points of the fundus which we have * [The fact that the papilla appears to change its nhape as the convex lens is withdrawn from the patient's eye is of itself a proof of astigmatism. On the other hand, an apparent change in size of the papilla, without change of shape occurring when the convex lens is gradually withdrawn, points to simple hypermetropia or myopia — to the former if the disk appears to diminish, and to the latter if the disk appears to enlarge. If the convex lens is placed so that its focal point is a little farther from the eye than the anterior focus of the latter (i. e., is rather more than half an inch in front of the cornea), there will be no distortion of the image of the disk from astigmatism, and no apparent increase or diminution in size due to myopia or hypermetropia. As this is the position of the lens which gives an undistorted view of the fundus, it is the one that should habitually be used in making examinations by the indirect method — i. e.. a 2-inch lens should be held 3J inches, and a 3-inch lens 8-J- inches in front of the cornea. — D.] 26 EXAMINATION OP THE EYE. fixed upon lie all in the same plane, they do not change their relative position to each other -with the shifting of the convex lens. If, on the contrary, a dif- ference of level exists between them, we notice a displacement with relation to each other, so that they now come nearer together, now go farther apart. Fig. 17 may elucidate what takes place. Let a be a point on the edge, 6 a point behind it, on the bottom of an excavation of the optic nerve. If the convex lens stands at I, the images of the two points ai and i, fall behind each other and cover each other. If the convex lens is now brought to II, the image of the point a is reproduced at a^, that of J at Jj ; the points appear to have sepa- rated from each other. Had the convex lens been carried in the opposite di- rection, the apparent displacement of the two points would have taken place in the opposite sense ; it would have looked as if the edge of the excavation had been drawn over the bottom of it. From the magnitude of the displace- ment the difference of level of the two points can be estimated, but can not be exactly computed, as is possible with the aid of the erect image. CHAPTER II. FUNCTIONAL TESTING. I 4. Besides instituting the objective examination, we have further to test the function of the eye. In doing this we are limited almost entirely to the statements of the patient, so that in this respect we are quite dependent upon the latter's intelligence and good will. Our visual sensations are of three different kinds, inasmuch as in looking at objects we take cognizance of their form, their color, and their brightness. The faculty by which we recognize the form of ob- jects is called the space sense, and finds its numerical expression in the visual acuity ; the faculty by which we distinguish colors constitutes the color sense; the faculty by which we distinguish different degrees of brightness constitutes the light sense. These three faculties are resident in the retina throughout its entire extent, although in very different degrees. In this regard we must distinguish between central and peripheral vision. Central or direct vision is vision with the fovea centralis. When we wish to see an object distinctly, we " fix " it — that is, we turn the eye in such a way as to make the image of the object fall upon the fovea centralis, as the latter, on account of its peculiar anatomical structure, gives us the sharpest vision that we are capable of. It is with reference to central vision that we test the refraction, the accom- modation, and the visual acuity. For more precise particulars in re- gard to these tests, see the third part of this book, which treats of the optical defects of the eye. Peripheral or indirect vision is vision with those parts of the retina which do not belong to the fovea centralis and which comprise by far the greatest part of the retina. Vision with the peripheral portion of the retina affords a less distinct, a duller sensation, of which we can best get an idea by holding the outspread fingers of our hand to one side of the eye, while the latter is looking straight ahead. The farther from the fovea centralis is the image produced upon the retina, the more in- distinct is the perception of its shape. For perceptions of movement, on the other hand (Bxn^r), as well as of slight differences of luminosity, the periphery of the retina is actually more sensitive than the center. 27 28 EXAMINATION^ OF THE EYE. Of what use, then, is peripheral vision, if we can get no well-defined perceptions with it ? We can best understand this by observing per- sons who have lost peripheral vision to such an extent that only the fovea centralis and its immediate vicinity retain their functional activity, as happens in many diseases, especially in retinitis pigmentosa. Such persons can sometimes still read the finest print, and yet are in no condition to go about alone. We can put ourselves in this condi- tion if we fasten in front of the eyes a long tube which allows us to see only the point lying directly in front of our line of vision. We can not go about with such an apparatus, because we strike against objects everywhere. Peripheral vision, therefore, is of service in orientation. How ? If, as we are walking, we look straight before us and there is a stone lying in our path, the latter forms an image in the periphery of the retina of our eye, in this case in the upper part of it. The stone, to be sure, is not distinctly perceived, but still it excites our attention. Our gaze is then directed at it ; it is seen directly ; we recognize it as an obstacle, and avoid it. The same thing happens if we go out upon the street and men come toward us from one side, etc. The images falling upon the periphery of the retina give us warning signals which make us cast our eye directly upon the objects which excite the images. And it is precisely moving objects that are most sure to attract our attention, since, as just stated, the peripheral portions of the retina have a high degree of sensibility for the perception of movement. 5. Examination of the Field of Vision.— The examination of the field of vision — that is, of the limits of indirect vision — must be made for each eye separately. The eye examined is directed at a fixed point, in order that it may thus remain steadily in the same position, while the other eye is kept closed. The simplest way of investigating the extent of the field of vision is by using the hand as a test object. The physician places himself directly in front of the patient and at a short distance from him ; the patient looks with one eye at the physician's eye directly opposite. The physician now closes his other eye (as does the patient), and gradually moves his hand from the periphery inward over the limits of the field of view ; the patient must tell as soon as he sees the hand. In this way the physician has in his own eye a means of judging the field of view of the patient ; if this is normal, the patient must see the hand at the same time that the physician does with his eye. This method is sufficiently exact for the recognition of the larger encroach- ments upon the visual field ; but small defects can not be thus recog- nized. It is the only method of testing applicable in those cases in which smaller test objects are no longer made out because the vision is too poor. If the patient is lao longer in condition to see even the hand, we must make use of a candle flame which we carry about FUNCTIONAL TESTING. 29 through the field of vision. In this way, for instance, we test the vis- ual field of a person who is blind from cataract. We can get at the field of vision more exactly by means of a Mach- hoard. We place the patient before this and take care that during the examination the dis- tance between the eye and the board remains always the same (e. g., 30 cm.). Directly oppo- site the patient's eye we make a mark on the blackboard with chalk, and direct him to fix his gaze on this mark during the examination. The chalk is now gradually brought from the edge of the blackboard to its center, and the patient is to tell at what moment he first sees it. By marking on the blackboard the limits of the visual field in every direction and connecting the points thus determined, we fix the extent of the field of vision. The size of the latter is, of course, in direct proportion to the distance at which it is taken. Even this method is not en- tirely free from drawbacks which spring from the difficulty of projecting a hollow sphere like the retina upon a plane. One important drawback is that un- equal distances in the field of vision correspond to equal dis- tances on the retina. Thus, in Fig. 18, the distances m a and i c upon the retina are equal, each corresponding to an angle of ten degrees. In the field of vision projected on the board, T T, however, the section (from 70° to 80°) that corresponds to the second region of the retina is many times greater than that (from 0° to 10°) which corresponds to the first. Hence, a spot upon the retina of definite size that has become insensitive to light would in such Hog o.2o m ■ c ^ -* «^ * ^ ss ^ £ 2 o 1-1(4-1 '3 O (u eg « y ^ Dj o g o p, 5.2 ■a S "iS t. > \jg OJ t^ ed ^ 0) _ O 03 ft 2 ftfl gJ cc tea) g 30 EXAMINATION OF THE EYE. a visual field appear as a gap, the size of which would be quite different according as it is nearer to or farther from the center, and thus mis- takes might be caused. A second evil is that the whole of a normal visual field does not find a place on a plane, be the latter ever so large. The normal field of vision, that is, extends outward to 90° and more. Right Eye. 360 Fio. 19. ISO -Field of Vision op the Right Eve for White, Blue, Red, and Qreen, for a Test Object of 20 Square Mm. (After Baas.) F^ point of fixation ; M, Mariotte's blind spot. Therefore, as is evident from Fig. 18, the temporal limit of the visual field can never be projected on the board. After what has been said, therefore, there is only one exact method of representing the visual field, and that is the projection of it upon a hollow sphere (Aubert). Upon this principle different perimeters are constructed. To Forster belongs the credit of having introduced this instrument into ophthalmic practice. Forster's perimeter consists, not of a complete hemisphere, but of a metallic semicircle (Fig. 18, P) which represents, as it were, one meridian of the hemisphere. The semicircle is capable of being revolved so as to take the direction of each meridian in succession. The patient supports his head on a chin PUNCTIOKAL TESTING. 31 rest which is so placed in front of the semicircle that the eye to be ex- amined is situated in the center of curvature of the latter. In the ex- amination the eye must be fixed upon the middle point of the semicir- cular arc, while the mark that serves for the test is carried to and fro along the latter. A scale of degrees marked upon the semicircular arc enables us to read ofE directly the situation of the boundary of the vis- ual field, and the result obtained is transferred to a diagram (Fig. 19). 6. Extent of the Field of Vision.— The normal field of vision, as a glance at the appended diagram (Pig. 19) shows, does not by any means extend equally far in all directions. It stretches farthest toward the external (temporal) side, where it has an extent of over 90°. Accordingly, we can still see objects on the temporal side, al- though they lie in, or even somewhat behind, a plane passing through the pupil (for example, the point in Pig. 18). This is rendered pos- sible by the fact that the rays from such a point undergo such strong refraction at the surface of the cornea that they can still enter the pupil. The field of vision is much less extensive in other directions, especially in directions inward and upward. The cause of this is to be sought for in the fact that the nose and the eyebrows project into the field of view and limit it. This obstacle can indeed be partially over- come by making suitable rotation of the head while the field of vision is being examined, but even then we never find the field of vision as extensive on the nasal side as it is on the temporal. The cause of this is that the margin of the percipient layers of the retina does not extend as far forward on the temporal side as on the nasal (Pig. 18, d and e). The pathological alterations of the visual field consist in its cur- tailment. This is either produced by a pushing in of the boundary of the visual field at some point, or it occurs under the form of gaps lying like islands inside of the field of vision. Narrowing of the visual field at the periphery presents varying characters. If the limits of the visual field are brought nearer to the center from all points alike we speak of a concentric contraction. When this is considerable, it results in that incapacity for orientation which has been already described, although it may be that direct vision (visual acuity in the narrower sense) is still quite good. In other cases, the contraction extends from one side only of the periphery into the visual field. If it has the shape of a triangle whose base corresponds to the periphery of the visual field, it is called a sector-shaped contrac- tion. A peculiar variety of contraction of the visual field is the hemi- opic, in which exactly one half of the field is wanting (see § 100 and Figs. 153 and 153). Islandlike gaps in the visual field are called scotomata* One of * From itk6tos, darkness. 32 EXAMINATION OP THE BYE. these exists in the healthy eye at that point of the visual field which corresponds to the entrance of the optic nerve, and is known as Mari- otte's blind spot (Fig. 19, M). In the field of vision it lies about 15° to the outside of the point of fixation, F. The scotomata which occur as the result of disease have a very different significance for vision ac- cording to their situation ; and, according to the latter, we distinguish them into central and peripheral. A central scotoma is one which in- volves the point of fixation (cf. Pig. 158). In this case direct vision is either greatly diminished or is abrogated altogether. The patient can no longer do any fine work, although his power of orientation remains intact. Peripheral scotomata cause little disturbance of sight, espe- cially if they lie far from the point of fixation, in which case they may not come to the patient's knowledge until his visual field is being examined. A special variety of scotoma is the annular, which encircles the point of fixation like a ring (which is not always completely closed), but leaves intact the point of fixation itself. Von Graefe was the first to call attention to the importance of testing the visual field in ophthalmic practice. He showed that for many intra-ocular dis- eases there are special varieties of contraction of the visual field, which are more or less characteristic of these diseases, and can be utilized for their diagnosis. Since then the study of the visual field has been much cultivated, so that at present its examination has great significance, both for diagnosis and prognosis. ConcenPric contraction of the visual field, associated with retention of good central vision, we meet with especially in retinitis pigmentosa, and sometimes also in glaucoma. In other diseases which are frequently accompanied by con- centric contraction of the visual field, as, for instance, in atrophy of the optic nerve or of the retina, central vision is also simultaneously and markedly affected. We find the sector-shaped deficiencies especially in atrophy of the optic nerve ; also in occlusion of one of the larger retinal arteries, when the sector-shaped district of the retina supplied by such an artery has its function abrogated. We observe more extensive, although not triangular, contractions of the visual field in detachment of the retina, and these most often extending in an upward di- rection, since the detachment, if of long standing, generally involves the lower- most part of the eye. In glaucoma a contraction of the visual field toward the nasal side is of relatively frequent occurrence. Scotomata are most frequently met with in diseases of the fundus with cir- cumscribed lesions ; especially, therefore, in chorioiditis disseminata, in which, as a rule, the gaps in the visual field correspond to the separate macuto visible with the ophthalmoscope. So long as these gaps afifect the periphery only of the visual field, they cause little disturbance of sight. If they are very numer- ous, the visual field acquires a sievelike character. If, finally, one of the cho- rioiditic masses is localized at the region of the chorioid corresponding to the yellow spot, the visual power is very considerably reduced by the formation of a central scotoma in addition to those in the periphery. Isolated central scotomata occur in diseases of the retina and chorioid at the posterior pole of the eye, especially as a result of syphilis, of myopia of a high degree, and of senile changes. In all these cases there corresponds to the sco- FUNCTIONAL TESTING. 33 toma a change in the macula lutea, visible with the ophthalmoscope. In another series of cases, on the contrary, a central scotoma exists, -while the result of the ophthalmoscopic examination is negative ; the cause of the scotoma is then to be looked for in the optic nerve. In the latter it is just those fibers ■which supply the region of the macula lutea that are the most favorite seat of disease (in retrobulbar neuritis; see § 103). As the expression scotoma is used in different senses, it will require in this place a more precise explanation. We distinguish between positive and nega- tive scotomata (Forster). By a positive scotoma we understand a dark spot which the patient perceives in his visual field — projects, that is, upon some portion of his visual field. The cause of a positive scotoma lies either in the refracting media or in the retina. Opacities in the refracting media throw their shadow upon the retina, and are therefore visible as dark spots. If the opacities lie in the vitreous they are motile (muscaa volitantes), and the scotomata caused by them axe characterized as motile scotomata. Fixed scotomata originate either from stationary opaci- ties (e. g., those in the lens), or, still more frequently, from changes in the fundus (e. g., from an exudation in the retina or in the chorioid adjacent to it). Scotomata of the latter kind are best brought to light by making the patient fix his gaze upon a uniformly bright surface (e. g., a sheet of white paper). They are often more readily perceived if the illumination is at the same time diminished (as by letting down the window curtains). We can direct the patient to make a copy of the dark spots that become visible upon the paper, and from this we can determine the position and extent of the diseased portions of the retina. We characterize as a negative scotoma a hiatus in the visual field, an isolated spot within the confines of which the patient does not perceive any external objects. Such a scotoma, accordingly, is not discovered as a rule until the visual field is examined. But there is nothing to prevent a negative scotoma from being at the same time a positive one too; the same diseased regions of the retina that are insensitive to external luminous impressions can at the same time be themselves perceived as dark spots and be projected exteriorly. Negative scotomata are divided into absolute and relative. An absolute scotoma is present if within its limits all perception of light is wanting, while with relative scotomata the perception of light is merely diminished. We dis- cover a relative scotoma by making the examination of the visual field with small objects, and especially by choosing colored objects for this purpose. For with a certain diminution of the visual power the ability to distinguish colors accurately disappears, while the objects themselves, owing to differences in their luminosity, can still be recognized. For example, in a recent case of chronic poisoning by nicotine, the visual field, measured with the aid of a white test object, may seem quite normal ; but if a small red paper disk is chosen for the examination there is a small region in the center in which the disk is no longer recognized as red. A relative scotoma is present, and that, moreover, a color scotoma (scotoma for red). Even in the normal visual field the perception of colors is not everywhere the same. Just as in regard to the visual acuity, so also in regard to the color sense, a distinction must be made between central and peripheral color percep- tion. While the former is tested by the mere exhibition of colored samples, the latter must be investigated, just like the visual field, by using as test objects Si EXAMINATION OP THE EYE. colored marks, which are moved to and fro on the board or on the perimeter. The bigger and brighter the colored surfaces used for this purpose are, the fur- ther toward the periphery will their color be distinguished, and when very large and bright they will be distinguished up to the extreme limits of the field. But when the examination is made with the ordinary test objects used with the perimeter (colored squares of paper, 1 to 3 cm. in diameter), the most peripheral portions of the retina are found to be color blind. If such .? colored square is pushed from the periphery of the visual field toward the cen- ter, the person examined at first recognizes only the presence of a moving object. It is not till the square approaches nearer the center of the visual field that its color is correctly given. The moment when this occurs is not the same for all colors, some being recognized farther out from the center than others. The visual field for green is the smallest, that for red somewhat larger, that for yellow still larger, that for blue the largest (see Fig. 19). The examination of the visual field with colored objects is of great practical importance. For instance, we find in one case the visual field normal when tested with white, while the examination with colors shows already a consider- able introcession of its borders at one spot. After some time, if the disease has progressed, we now, on testing with white, establish the same deficiency in the visual field that had before existed for colored objects only. The examination with colors is accordingly a more delicate test than that with white ; it makes us discover a diminution of the visual power before it has advanced so far that a white object can no longer be recognized. If, therefore, we take two cases in which the visual field for white is equally large, but the visual field for colors is unequal, that case in which the visual field for colors is smaller affords the worse prognosis, since here a still further diminution of the general visual field is to be expected. Rapid diminution of color perception is pre-eminently associated with the progressive lesions of the optic nerve that lead to blind- ness. The examination of the visual field with colors is also requisite for the recognition of central scotomata, so long as they are not absolute. Furthermore, the way in which the color sense is diminished gives us a clew as to the site of the morbid changes. Thus diminution in the perception of blue corresponds to a lesion of the percipient elements (rods and cones) of the retina, such as occurs in chorioiditis, retinitis, and hemeralopia ; diminution in the perception of red and green to a lesion of the conducting elements, as in affections of the optic nerve. Light Sense.— Let us assume that we have before us two persons who in ordinary daylight have the same visual acuity ; both under equally good illumination read print of the same size at the same distance. We now gradu- ally lessen the illumination. As a result of this, the difference in brightness between the black letters and the white paper diminishes and the letters are dis- tinguished with greater and greater difficulty. At a certain stage in the process of obscuration, one of the two persons ceases to recognize the print while the other is still able to read, and the darkening has to be carried further in order to make reading impossible for him. In this case we say : The two persons have the same space sense, i. e., the same susceptibility of the retina for impres- sions of forms, but they have a different light sense (i)— i. e., a different sus- ceptibility for impressions of brightness and of differences of brightness. The light sense can be tested in various ways. We determine either the lowest Umit of illumination with which an object is still visible (minimum E^UNCTIONAL TESTINa. 35 Fig. 20.— Photometer of FOrster. stimulus) or the smallest difierence in brightness which can still be appreciated (minimum of differentiation). The most usual method of measuring the light sense is with Forster's photometer, which gives the minimum stimulus. This instrument, which is represented in horizontal section in Fig. 20, is placed in a perfectly dark room. A box. A, blackened on the inside, bears on its anterior wall two apertures for the two eyes, a and a,, which look through these aper- tures at a plate, T, which is placed upon the posterior wall, and upon which large black stripes upon a white ground are placed as test objects. The illu- mination is produced by a normal candle,* £, the light from which falls through a window, F, into the inte- rior of the box. In order to make the illumination perfectly uniform, the win- dow is covered with paper which is made translucent (by impregnating it with fat). By a screw, 8, the size of the window can be al- tered from complete closure up to an aperture of five square centimetres. In this way the illumination of the plate is varied. The patient is then made to look into the apparatus with the window closed and the plate therefore unillumined. Then the window is slowly opened until the stripes upon the plate can be recognized. The size of the opening requisite for this purpose gives a measure of the light sense of the person examined. In con- ducting this examination the precaution must be adopted of making the person that is examined stay beforehand in darkness. If we come from daylight into a moderately darkened room we see so little for the first moment that we can not move about without stumbling over the objects in the room. The longer we remain in the latter the better we see, and at last perhaps see well enough to be able to read. This we call adaptation of the retina. In the examination of the light sense, a period of adaptation of ten minutes, which the patient must pass with bandaged eyes in a perfectly dark room, is sufiicient for prac- tical purposes. The examination of the light sense in different diseases has shown that it is not always by any means diminished in proportion to the visual acuity, but is sometimes but little diminished, sometimes excessively so, a circumstance from which diagnostic points may be gathered. The diminution of the light sense is greatest in those cases which are characterized as hemeralopia (see § 104). SiMDLATiOK or BLINDNESS. — In testing the function we shall at times have to reckon with the fact that the patient is purposely trying to lead the physician astray by simulating blindness or weakness of sight when these do not exist. This most frequently occurs with those persons who wish to be relieved of mil- itary service or who wish to get testimony as to their inability to work ; some- times also with children, hysterical persons, etc. We are first led to suspect simulation by the lack of agreement between the results of the functional test- [* I. e., one of one-candle power, — D.] 36 EXAMIXATION OP THE EYE. ing and of the objective examination; an eye, for example, which is alleged to be perfectly blind presenting no pathological changes of any sort. Or the tests of the individual functions give contradictory results, inasmuch as the visual acuity, the field of vision, the color sense, etc., do not stand in the right relation with each other and with the result of the objective examination. Various methods of examination have been proposed for furnishing a certain proof of simulation ; we shall accomplish this more or less readily by their aid according ;to the degree of skill of the simulant. Only some of these methods need be here adduced. Complete blindness of both eyes is. rarely simulated; much oftener it is simply unilateral blindness that is alleged ; and still more frequently a feeble- ness of sight actually present in one eye is exaggerated (aggravation). In the case of an alleged complete blindness of one or both eyes we regard in the first place the reaction of the pupil to the light. If this is well preserved, it will always afford a strong ground for suspecting simulation, although there are rare cases in which in the presence of actual blindness the pupillary reflex for light is still retained (see § 64;. Sohmidt-Kimpler recommends the following procedure : The patient is made to look with the blind eye at his own hand, which he holds in front of him. A blind man will do this without hesitation since he is informed of the position of his hand by the sense of feeling; a malingerer will perhaps look purposely in the wrong direction. Simulated uni- lateral blindness can also be discovered in the following way : A lighted candle is brought in front of the good eye and is slowly carried toward the side of the blind eye. The patient is detected if he declares that he still sees the candle at the moment when it is just concealed from the sound eye by the dorsum of the nose (Cuignet). The following methods are furthermore of service in detecting the simula- tion of unilateral blindness or amblyopia. 1. We make the patient read, and then hold a pencil in a vertical direction between the eye and the book. If there is vision with only one eye the pencil conceals certain words from it, and thus interferes with reading. If, however, there is good vision with both eyes, those letters which are concealed from one eye by the pencil are visible to the other, and vice verm, and reading is carried on without difficulty (Cuignet). 3. A convex glass of 6 D. is placed before the sound eye. In this way the eye is made artificially myopic, so that its far point lies at a distance of about 17 cm. (it being presupposed that the eye is emmetropic). The eye can there- fore read fine print only at a distance of 17 cm. or less, but no farther. After placing the glass before the eye we first make the patient read at quite a short distance, and then slowly and imperceptibly move the book farther and farther away. If it is possible in this way to withdraw the book considerably farther than 17 cm. without the patient's ceasing to read, it proves that he has been reading with the eye alleged to be bad. That is, he began reading with the good eye and, when the book was carried too far oS for that, continued witli the other eye, without noticing the alternation in the employment of the two eyes. 3. We make a show of occupying ourselves with the sound eye only. We take a strong prism (one of 18°), with the base up, and, first holding it in front of the cheek, push it gradually up in front of the eye. Before the base has reached the center of the pupil the eye will see double. For two images FUNCTIONAL TESTING. 3Y of every external object will be thrown upon the retina, one transmitted through the free half of the pupil, the other through the half covered by the prism, and the eye sees double the object upon which it is fixed (monocular diplopia)— a fact which the patient will admit without hesitation, since, of course, it is the sound eye only that is concerned in the matter. Now the prism is imperceptibly pushed along until it covers the entire pupil. Now the eye that is provided with the prism again has only one single retinal image, which, however, is thrown upon a higher point of the retina than is the case in the other eye. If now there is still double vision (binocular diplopia), it is a proof that both eyes see. If -^ve use the test types for this examination and com- pel the person under examination to read sometimes the upper, sometimes the lower of the two double images, we can determine directly the visual acuity of each eye separately without the patient being aware of it (Alfred Graefe). 4. Snellen has constructed a board with test types which are alternately red and green. Before the patient is allowed to read it, a pair of spectacles is put upon him, in wliich are introduced a red glass for one eye and a green glass for the other. Through the red glass the red letters alone, and not the green, can be seen, because green is the complementary color of red, and therefore green rays are not transmitted through red glass. For the same reason the red letters can not be perceived through the green glass.* If, therefore, any one who is blind in one eye looks through these spectacles at the test types, he will read off only the red, or only the green letters, according as the red or the green glass of the spectacles is placed in front of the eye which alone can see. He will not once suspect that still other letters of a different color lie between the letters that he has read. Should the patient, on the other hand, read all the letters, it proves that he sees with both eyes and in such a way as to recognize the red letters with one eye and the green with the other. 5. Letters are written on white paper with a black and a red pencil alter- nately. The subject under examination is then told to read the writing rap- idly, while a red glass is held before the sound eye. If he reads the whole correctly, it is a proof that he is able to read with the eye alleged to be blind, for the sound eye, looking through the red glass, can not see the red letters, since these now offer no contrast to the background upon which they are viewed, which appears as red as they. For the tests for the motility of the eye and for binocular vision, see § 132. * [In this test of Snellen's the red and green letters are transparent and placed upon an opaque ground and are hung up before a window so as to be seen by transmitted light. In this case, as stated in the text, only the red letters are seen through the red glass, and only the green through the green glass. The same will occur if the red and green letters are opaque, and placed on a dull black ground, and viewed by reflected light. In either case the conditions are opposite to those which exist in the test next mentioned, in which opaque red letters are viewed by reflected light on a white ground. — D.] PAET II. DISEASES OF THE ETE CHAPTEE I. DISEASES OF THE CONJUNCTIVA. Anatomy. 7. The conjunctiva coats the posterior surface of the lids and the anterior surface of the eyeball. It forms a sac, the conjunctival sac, which is slit open anteriorly in a line corresponding with the palpebral fissure. In the conjunctiva we distinguish three divisions. That part of the conjunctiva which covers the posterior surface of the lids and which is closely adherent to the tarsus is called the conjunctiva tarsi ; that division which coats the anterior surface of the eyeball is the con- junctiva bulbi. The connection between the two is formed by the third division, which we name the transitional part of the conjunctiva (conjunctiva fornicis). That region where the conjunctiva is reflected from the lids to the eyeball and which forms the bottom of the con- junctival sac is called the fornix conjunctivae. We get a view of the conjunctiva tarsi in the living eye by evert- ing the lids. It has a smooth surface and is intimately and immova- bly adherent to the subjacent tarsus (Fig. 21, t). (It is therefore im- possible to cover up losses of substance of the palpebral conjunctiva by performing an operation to draw the adjacent conjunctiva over them, as is often done with the conjunctiva bulbi.) On account of its thinness, the conjunctiva tarsi allows the Meibomian glands, which lie in the tarsus itself, to be seen through it clearly. The microscope shows that the palpebral conjunctiva is covered with a laminated cylindrical epithelium. The mucous membrane proper is of adenoid character — that is, even in the healthy state it contains an abundant quantity of round cells (lymph corpuscles), which notably increase in number with every inflammation of the conjunctiva. Of glands it possesses acinous mucous glands, which are found along the convex border of the tarsus (Pig. 31, m>; Waldeyer) ; analogous glands (Kranse's glands, Fig. 162) are present in the fornix conjunctivse. 38 DISEASES OF THE CONJimCTIVA. 39 The conjunctiva of the upper lid obtains its blood supply from two arterial arches, the arcus tarseus superior {as, Pig. 21) and the arcus tarseus inferior (at, Fig. 31). These lie upon the anterior surface of the Fig, 21.— Perpendicular Section through the Upper Lid. Magnified 5x1. The skin of tlie lid ]oresents in the upper part, above a sulcus, the protecting fold, d ; below, it covers the anterior edge of the lid, v. In the skin are found fine hairs, e, e, sweat glands, a, cilia, c, c, c, and in the neighborhood of the latter Zeiss's glands, z, and the modified sweat glands, s. Beneath the skin lie the transversely divided bundles of fibers of the orbicularis, o, o, of which those placed most internally, r, r, form the musculus ciliaris Riolani. The posterior surface of the lid is covered by conjunctiva which is intimately adherent to the tarsus, f, and over the latter shows isolated papillae, especially at co, over the convex border of the tarsus. Still higher up, at h, in the vicinity of the fornix, the conjunctiva shows an adenoid character. The Meibomian glands, g, have their orifices, vi, in front of the poste- rior edge, ft, of the lid ; above them he Waldeyer's mucous glands, w, and still higher Miil- ler's musculus palpebralis superior, p, and the levator palpebrse superioris, I. From the latter the leash of fibers, I, passes to tne skin of the lid. as is the arcus tarseus superior ; at, the arcus tarseus inferior ; from the latter the rami perforantes, rp, run, at first straight downward, then backward, through the tarsus. tarsus, near its upper and its lower edges. To reach the conjunctiva, the branches of the arcus tarseus inferior (rp, Fig. 21) perforate the tarsus through its entire thickness from before backward, two to three 40 DISEASES OP THE EYE. mm. above the free edge of the lid. The line along which the vessels come out from the tarsus is marked by a shallow furrow (sulcus sub- tarsalis) on the conjunctival surface of the lid. On the lower lid there is only one arterial arch. The conjunctiva of the region of transition is very readily brought to view in the lower lid by drawing the lid down while the eye looks up. In the upper lid, on the contrary, the fold of transition is hard to see, unless we make a double eversion of the lid. The region of transition is the loosest part of the conjunctiva, this being here so abundant that it lies in horizontal folds. This arrangement insures the eye its free power of movement. If the conjunctiva were to pass directly from the lid to the eye, as is sometimes observed in conse- quence of disease of the conjunctiva, every movement of the eyeball would be transmitted to the lids ; and if one of the lids was held still with the finger, the eyeball would be hampered by it in its movements. But the conjunctiva is present in such quantity at the fornix that the eye is able to move in complete independence of the lids, the folds in the region of transition being smoothed out or crumpled together, as the case may be. Appearing through the lower fold of transition are the extensive subjacent plexus of veins and also the white glistening fascia. Its lax character and also its abundant blood supply render the fold of transition particularly liable to great swelling in inflammations of the conjunctiva. The conjunctiva bulbi covers the anterior surface of the eyeball. It has no aperture corresponding to the cornea, but continues, even if with altered character, over the latter. This continuity of the conjunc- tiva makes it plain to us why morbid processes of the latter do not stop at the margin of the cornea but are continued upon the surface of the latter, as we see very clearly in trachoma and in conjunctivitis ecze- matosa. The two divisions of the conjunctiva bulbi are distinguished as the conjunctiva scleras and conjunctiva corneas. The conjunctiva corneas is perfectly transparent, and is so intimately adherent to the cornea proper that it must be regarded as the uppermost layer of the latter, and is better treated of at the same time with the cornea itself (see § 27). The conjunctiva scleree covers the anterior segment of the sclera in the form of a thin pellicle. It is connected with the sclera by lax con- nective tissue (the episcleral tissue) so loosely that it can readily be moved about from side to side upon the sclera. It is only at the pe- riphery of the cornea, where it ends in a sharp edge, the limbus* con- junctivas, that the conjunctiva scleras is intimately adherent to its sub- stratum. It is very thin and elastic and lets the white sclera be seen through it plainly, thus forming the " white of the eye." In old people * Limbus, hem. DISEASES OE THE CONJUNCTIVA. 41 there is a spot at tlie inner and the outer margins of the cornea which contrasts by its yellow color with this whiteness. This has the shape of a triangle with its base at the corneal margin, and projects a little above the rest of the conjunctiva. It is called the interpalpebral spot or the Pinguecula,* and is produced by the fact that that part of the conjunctiva which, being included in the interpalpebral fissure, is con- stantly exposed to atmospheric influences, has undergone an alteration in its tissues. The conjunctiva sclerse is covered with laminated pavement epithe- lium and contains no glands. At the inner angle of the eye it forms a crescentic duplication, the semilunar fold (plica semilunaris), which rep- resents an abortive remnant of the palpebra tertia of animals. To the inside of the semilunar fold is a small, reddish, nipplelike prominence, the caruncle,! which occupies the bottom of the horseshoe-shaped ex- cavation at the angle of the eye (Fig. 30, 0). This is shown to be his- tologically a small island made of skin, containing sebaceous and sweat glands and having its surface covered with delicate light-colored hairs. The conjunctiva of the eyeball receives its blood-vessels chiefly from the vessels of the fold of transition — the posterior conjunctival vessels (Fig. 32, o and Oi). Furthermore, the anterior ciliary vessels (Fig. 22, e and e-i) take part in supplying the conjunctiva with blood. These vessels come from the four recti muscles (R, Fig. 22) and run under the conjunctiva (through which they are visible, shining with a bluish luster) until near the edge of the cornea, where they suddenly .disappear, since they pass through the sclera into the interior of the eye. But, before this happens, they give off branches which end in vascular loops, in the limbus conjunctivae directly at the margin of the cornea (marginal network of the cornea— g, Fig. 22). This latter is of great importance for the cornea which is chiefly dependent upon it for its nutrition. Other branches of the ciliary vessels (anterior con- junctival vessels, p, Fig. 22) run backward in the conjunctiva toward the posterior conjunctival vessels and anastomose with them. We have therefore in the conjunctiva two vascular systems — that of the posterior conjunctival vessels and that of the anterior ciliary vessels. According as the one or the other system is overdistended with blood, the conjunctiva has a different aspect, which we designate respectively as conjunctival and as ciliary injection. Conjtmctival hijection presents to us a superficially disposed net- work of larger and smaller vessels, whose situation in the conjunctiva is proved by the fact that when it is moved about they move with it. The color of the injection is a vivid scarlet or brick-red ; the individual vascular meshes are plainly to be recognized. This injection is charac- teristic of diseases of the conjunctiva itself. * Pinguis, fat. t Caruncula, dim. of caro, flesh. 42 DISEASES OF THE EYE. Ciliary injedioji occurs as a rose-red or pale-violet zone round the cornea (hence the designation peri- [circum-] corneal injection), in Fig. 22.~Blood-vessels of the Eye (Schematic, after Leber). The retinal system of vessels is derived from the central artery, a. and the central vein, Oj, of the optic nerve, which give off the retinal arteries, 6, and the retinal veins, fc,. These end at the ora serrata. Or. The system of ciliarti vessels is fed by the posterior short ciliary arteries, c. c, the posterior long ciliary arteries, d. and the anterior ciliary arteries, e. From these arise the vascular net- work of the chorioidal capillaries, /, and of the ciliary body, g, and the circulus arteriosus Iridis major, h. From this last spring the arteries of the iris, i, which at the lesser [inner! circumference of the latter form the circulus arteriosus iridis minor, k. The veins of the iris, i|. of the ciliary body, and of the chorioid are collected into the vasa vorticosa, I; those veins, however, that come from the ciliary muscle (m) leave the eye as anterior ciliary veins, ^i- With the latter Schlemm's canal, n, forms anastomoses. The system of conjunctival vessels consists of the posterior conjunctival vessels, o and Oj. These communicate with those branches of the anterior ciliarj- vessels which run to meet them ; that is, with the anterior conjunctival vessels, p, and form with these the marginal loops of the cornea, g^ O. optic nerve ; S. its sheath ; »c, sclera ; A, chorioid ; N^ retina ; i, fens ; fl, cornea ; i?, internal rectus ; B, conjunctiva. DISEASES OE THE CONJUNCTIVA. 4.3 which we are unable to recognize clearly any individual vessels. With injection of greater intensity we see, still farther removed from the cornea, a coarser network of vessels, which are to be recognized as deeply placed by their violet color and their hazy appearance ; by the fact, moreover, that when the conjunctiva is displaced they do not move with it. Ciliary injection is most markedly distinguished from that of the conjunctiva by its violet hue as well as by the diffuse ap- pearance of the redness, due to the fact that the individual engoro-ed vessels are recognized either indistinctly or not at all. Ciliary injection most frequently accompanies diseases of the cornea, and also of the iris and the ciliary body, parts which belong to the vascular district of the anterior ciliary vessels. On account of the numerous anastomoses be- tween the two vascular districts of the conjunctiva, we find both in- jected in every inflammation of any great violence in the anterior sec- tion of the eyeball ; it is, however, still generally possible to recognize, along with the superficial conjunctival injection, the ciliary injection, more deeply situated and directly surrounding the cornea. The conjunctiva of the tarsus is really perfectly smooth only in the young. In older persons we find it having a velvety surface on the upper lid toward the angles of the tarsus, and often also along the entire convex edge of the tarsus (Fig. 21, CO). This condition of the conjunctiva we call papillary. In reality, however, it is not, properly speaking, papillse which are here found in the conjunctiva, but fine folds into which the surface of the somewhat hypertro- phied conjunctiva has been thrown. In microscopic sections through regions of the conjunctiva, which have undergone this change, the transversely divided folds look like papillse, between which the epithelial lining dips down deeply. Should the sloping sides of two such folds lie very close to one another, the epithelial-lined depression between the folds can in cross-section give the im- pression of its being a glandular tube (i, Fig. 25). In this way is to be ex- plained the alleged new formation of tubular glands, which have been found in some cases of so-called papillary hypertrophy of the conjunctiva. Nevertheless, it is not to be denied that true tubular glands do exceptionally occur in the conjunctiva, both normal and diseased. These are called, after their dis- coverer, Henle's glands (Pig. 36, d). Furthermore, in middle and advanced life there are found, frequently in the fold of transition, less often in the palpe- bral conjunctiva, little yellow dots resembling the infarcts of the Meibomian glands (see § 108). This again is an instance of the new formation of tubular glands, in which develop concretions that are visible through the conjunctiva and then form the yellow dots. In the epithelium of the conjunctiva, particularly in its uppermost layers, are found cells which are undergoing a mucous metamorphosis {beaker cells). They occur but sparsely in the normal conjunctiva, but multiply to a great extent in inflammatory disorders of the latter. With regard to the papillary character of the conjunctiva at the upper border and at the angles of the tarsus, it is a question whether this is ever to be considered as perfectly normal and not rather as a product of repeated hyperss- mia of the conjunctiva. The same question must be put in regard to the ade- noid character of the conjunctiva, which is looked upon by many as also the 44 DISEASES OF THE EYE. residuum left by a previous inflammatory irritation. Since this mucous mem- brane is exposed more than any other to external influences, attacks of hyperae- mia of it occur often to every man in the course of his life, and these may result in permanent alteration of the membrane. The action of external injuries shows itself most plainly in forming the Pinguecula. This corresponds precisely to that region of the conjunctiva which is most exposed to wind, dust, etc. This interpalpebral spot owes its name Pinguecula to its yellow color, which was formerly referred to deposition of fat in the conjunctiva. What actually exists, however, is a thickening of the con- junctiva, chiefly as the result of an increase in the number and size of its elastic fibers. Associated with this is the formation of numerous concretions of a yellowish hyaline substance, to which in fact the pinguecula owes its yellow color. As a result of these changes, the conjunctiva in this place becomes less transparent, for which reason the pinguecula appears most prominent when the conjunctiva bulbi is markedly reddened, whether from injection or from extrav- asation of blood. In this case the pinguecula does not allow the red color of the blood to shine through as plainly as does the adjacent conjunctiva that is not thickened, and the former, therefore, stands out from the red substratum in the form of a light-colored triangle, so that by beginners it is easily confounded with a diphtheritic infiltration of the conjunctiva, or, when the yellow color is pronounced, with a small pustule. I. COI^JUNCTIVITIS CaTARRHALIS. {a) Conjunctivitis Catarrhalis Acuta. 8. Symptoms. — Acute conjunctival catarrh, in the liglder cases, chiefly affects the conjunctiva of the lids and of the region of transi- tion. The conjunctiva of the lids presents a vivid redness and is re- laxed. The injection is usually reticulate — i. e., the separate vessels can still be distinguished as such ; it is only when the injection is espe- cially dense that the conjunctiva acquires a uniformly red appearance. The surface of the conjunctiva is smooth ; catarrh is thus distinguished from some other forms of inflammation of the conjunctiva in which the latter is infiltrated and subsequently hypertrophied, as shown by the unevenness of its surface. The fold of transition (as well as the semilunar fold) is likewise greatly reddened and is somewhat swollen, while the conjunctiva bulbi shows little or no change. The severer are distinguished from the lighter cases by the fact that the process invades the conjunctiva bulbi. The redness and swell- ing of the palpebral conjunctiva are greater, and moderate oedema of the lids is often present at the same time. The conjunctiva of the eyeball shows both a dense reticulate reddening and a slight degree of swelling. Very frequently we find in the midst of the reticulate injec- tion red-colored spots— i. e., small haemorrhages, ecchymoses of the conjunctiva— produced by the rupture of small vessels. The severer cases, in which the conjunctiva is affected throughout its entire extent are designated under the name of ophthalmia catarrhalis, to distin- DISEASES OF THE CONJUNCTIVA. 45 gnish tliem from the lighter forms, which are named simply conjunc- tivitis catarrhalis. Inflammation of the conjunctiva is accompanied by increased con- junctival secretion. This secretion appears under the form of flakes of mucus, swimming in the abundant lachrymal fluid. The more in- tense the inflammation the greater the secretion, and the more the character of the latter changes from mucous to purulent. Violent cases of ophthalmia catarrhalis, therefore, are in their inception often hard to distinguish from an acute blennorrhoea of light intensity, although, of course, the subsequent development of the case makes the diagnosis clear. The secretion which exudes from the palpebral fissure dries at night upon the edges of the lids and glues them together. The subjective symptoms consist of photophobia, and of itching and burning of the eyes. The intensity of the annoyance given depends naturally upon the degree of inflammation. Violent pains, however, are but rarely present, and then, as a rule, are excited, not by the catarrh itself, but by its complications (especially ulcers of the cornea). A very troublesome sensation that is frequently present is that of a foreign body being in the eye, caused by flakes and filaments of tough mucus in the conjunctival sac. If such filaments lie upon the cornea, they produce the disturbances of sight of which the patients sometimes complain. These are distinguished from visual disturbances of more serious character by the fact that clear vision is immediately restored by brushing the mucus off with the lids. It is a characteristic feature of catarrh that all its disagreeable characters are least pronounced in the morning, and afterward gradually increase until they reach their highest point in the evening. Course. — This is favorable in uncomplicated cases, the inflamma- tion disappearing spontaneously after from eight to fourteen days. Not infrequently, however, there remains a condition of chronic in- flammation (chronic conjunctival catarrh), which, to be sure, causes less annoyance than the acute stage, but which is yet protracted over a comparatively long time. In the majority of cases acute conjuncti- val catarrh attacks both eyes, either both simultaneously or one eye a few days after the other. The complications which are observed in catarrh are corneal ulcers and iritis. The development of corneal disease is manifested by an increase in the pain and photophobia. At first we recognize, in the neighborhood of the corneal margin, small gray points, which are ar- ranged in a row concentric with the corneal margin. On the days fol- lowing, these punctate infiltrations of the cornea become more numer- ous and at length confluent, so as to form a small gray crescent. By a process of superficial disintegration an excavation is produced, so that finally a crescentic ulcer is formed, situated very near the corneal margin and concentric with it. Such ulcers are characteristic of con- 46 DISEASES OP THE BYE. junctival catarrh and are hence called catarrhal ulcers. Ordinarily the ulcer becomes clean quickly and heals, leaving behind it a slight arcuate opacity ; in cases, however, that are of especial intensity, per- foration of the cornea may occur. The complications above mentioned are observed only in severe cases— that is, only in ophthalmia catarrhalis. They very often owe their existence to faulty treatment of the catarrh. Among the laity, all sorts of household remedies are in use for inflammation of the eyes, such as the application of raw meat, or of bread soaked in milk, or of cooked onions, or a bathing with urine, etc. Such remedies are well adapted to increase the inflammation and produce complications. But even simple warm or cold compresses can have the same results. Etiology. — Atmospheric influences are the most frequent cause of catarrh. Their noxious influence makes itself felt more at certain seasous than at others, so that catarrh of the conjunctiva occurs with especial frequency at these times. For instance, this is the case in the spring, when so many people are attacked by catarrhs of the air pas- sages, by coryza, coughs, etc., and at the same time conjunctival catarrhs too are generally present in especially great number. At this time real epidemics of conjunctival catarrh occur, and under these circumstances it is the violent form (ophthalmia catarrhalis) which is prevalent. Dur- ing such an epidemic, contagion, effected by a transmissioQ of the secre- tion from one individual to another, plays a part in spreading the disease. This can occur, especially among children belonging to one family, by the indiscriminate use of towels, handkerchiefs, etc. Therapy. — By suitable treatment the duration of a conjunctival ca- tarrh can be considerably shortened and the development of a chronic catarrh prevented. The sovereign remedy in all the more intense cases of catarrh is the cauterization of the conjunctiva with nitrate of silver. This should come into contact with the conjunctiva only, and not with the cornea. In applying it, we evert the lids so that their conjunctival surface looks forward. The latter is then brushed over with a two-per- cent solution of silver nitrate and the excess of the solution is quickly washed ofE with lukewarm water or with a weak solution of salt. We now find the surface of the conjunctiva covered with a delicate bluish- white pellicle. This is the superficial slough which the solution has produced. The immediate result of this procedure, which is called brushing the conjunctiva, is violent burning and marked irritation of the eye, an increase, in short, of all the inflammatory phenomena (stage of exacerbation). After this has lasted from a quarter to half an hour, according to the energy of our application, improvement gradually sets in. An examination of the eye at this time shows that the thin slough is separating and is being thrown off in the form of shreds. When this is completed, we find the eye paler and the patient feels relieved and much less annoyed by his catarrh than was the case before the applica- DISEASES OP THE CONJUNCTIVA. 47 tion of the brush (stage of remission). This improvement lasts from half a day to a day, according to the intensity of the catarrh. Then the troubles gradually increase again (recrudescence). This is a signal for repeating the application. As a rule, it is sufiBcient to make the application once a day, and best in the morning. Beginners must particularly avoid making the apjjlication too ener- getically. If this has been done, the pain that follows the application lasts uncommonly long (for hours), and we find that even after a pretty long time, indeed even on the following day, the slough is still adherent in places. This is a proof that the sloughing process has penetrated too deeply. If, in spite of this, we should repeat the application, we would produce a progressively deeper and deeper sloughing of the tis- sue, and increase the inflammation instead of curing it. We must omit the application, therefore, as long as the slough is still adherent to any part of the conjunctiva. Persons who are not able to visit the physician every day can be allowed to instill the silver solution at home. Since by this method the remedy comes into contact with the cornea, we must choose a weaker solution {-^ to ^ per cent), which, of course, acts less energet- ically upon the conjunctiva. This way of employing the silver solution is therefore resorted to only as a makeshift in those cases in which treatment by means of the brush is inapplicable from extrinsic reasons. When ihe inflammatory phenomena have in the main disappeared, the silver solution is exchanged for collyria that act less energetically, those namely that are employed in chronic catarrh, to which subject refer- ence must therefore be made for details (see § 9). In addition to our medicinal treatment of conjunctival catarrh, we must not forget to enjoin upon the patient general rules for taking care of himself ; telling him to keep the eye clean by washing it with lukewarm water, and to avoid smoke, dust, and bad air in general, and recommending him instead to pass his time in the open air. He must also refrain from straining the eyes much, especially in the evening by artificial light. In consideration, too, of the possibility of the spread of the disease by contagion, of which there is always a chance, the patient must take care not to use the same wash basin, towels, etc., with other people. ^ Catarrhal conjunctivitis, also called conjunctivitis simplex, is, like catarrh of the air passages, reckoned among the so-called refrigeration diseases (diseases produced by cold). This, according to our present lights, is to be understood as meaning that acute conjunctival catarrh is due to atmospheric influences, but only in the sense that morbific matter is brought to the conjunctiva through the atmosphere. Again, the direct transfer of morbific matter from a diseased eye to a sound one may be the cause of acute conjunctival catarrh, for, even though the contagiosity of this disease is but slight, the cases with abundant secretion are undoubtedly contagious. In the violent cases of ophthalmia catarrhalis, particularly in those that develop epidemically, there is found as the cause of 48 DISEASES OP THE EYE. the disease a very small bacillus, first described by Koch, afterwards by Weeks. Lighter cases, especially those that are associated with eczema of the angles of the lids, are caused by a diplobacillus (Morax, Axenfeld). The pneumococcus has been found in cases of acute conjunctivitis in small children, rarely in adults ; and the streptococcus in cases of catawh accompanied by lesions of the lachry- mal sac (Morax). Similarly dependent upon atmospheric influences is that form of acute con- junctivitis which accompanies hay fever. This aSection, which is pretty fre- quent in certain countries, attacks individuals who are predisposed to it in the beginning of the summer, and makes itself apparent by fever and also by violent catarrhal inflammation of the conjunctiva and of the air passages. While the infection which, in all probability, excites the catarrh of the con- junctiva comes to the latter from without in most cases, there are also instances in which a poisonous principle circulating in the blood causes the conjunctival inflammation. This is the case in the conjunctival catarrh which accompanies mea.sles, and indeed often forms the first prominent symptoms of it (see § 18). From the clinical picture of acute conjunctival catarrh, as sketched above, we sometimes find variations forming what are described as special varieties of catarrh. Among these variations belongs the development of so- called /oZKc?es, which will be described more precisely in § 10. Another variety of catarrh is vesicular catarrh, in which the conjunctiva of the tarsus is covered with numer- ous minute elevations, looking as if fine sand had been scattered over a moist glass plate (Arlt) ; according to Mayweg what we have to do with here is very small follicles. A third variety of catarrh is that which is given the name of the pustular form. In this, flat elevations develop upon the conjunctiva bulbi, mostly near the margin of the cornea. These break down into pus on their sur- face, and in this way are formed grayish or yellowish ulcers with somewhat ele- vated base and of the size of a millet seed or more. These have a great resemblance to the eSlorescences occurring in conjunctivitis eczematosa (§ 17). The distinction between the pustular form of catarrh and conjunctivitis eczema- tosa consists in the fact that in the former the phenomena of catarjhal inflam- mation are present in the conjunctiva of the lids and of the region of transition, while in conjunctivitis eczematosa these divisions x>i the conjunctiva take little or no part in the inflammation. Many regard this form as a mixture of con- junctivitis catarrhalis and conjunctivitis eczematosa. And, as a matter of fact, we must take this view into consideration in our treatment to this extent that in the beginning of the disease the application of the silver solution ordinarily proves to be the best thing, but later, after the more violent inflammatory phe- nomena have run their course, calomel is of the most service. The three varieties of catarrh just named are seen chiefly in children or in adolescents. They occur only as an exception in adults ; in the latter, on the contrary, we encounter much more frequently the crescentic ulcers of the cornea that result from catarrh, which are but rarely observed in children. Several crescentic ulcers may be present in the same eye at different parts of the cir- cumference of the cornea ; nay, more, by their confluence an annular ulcer may be formed, completely encircling the cornea. In the latter case the annular opacity which is left has a great resemblance to the arcus senilis comese (see § 37). In cases where such an annular ulcer has penetrated deeply, the very detrimental result of a permanent ectasia of the cornea has been observed. Fur the floor of the ulcer stretches, and consequently the margin of the cornea at the DISEASES OP THE CONJUNCTIVA. 49 point where the ulcer is situated is pushed forward, so that the whole cornea assumes an oblique position. If the ulcer completely surrounds the cornea, the latter may give way before the intra-ocular pressure and move forward en masse. In this case the region of the cornea inclosed by the annular ulcer lies like a watch glass on top of the marginal portions of the cornea (keratectasia ex ulcere, § 48). Nitrate of silver, our most important remedy in catarrh, was first employed for inflammations of the conjunctiva by St. Yves in the last century, although it was in this century that it first found general acceptation. People had a natural dread of instilling so irritating a liquid as a nitrate-of-silver solution into a violently inflamed eye. In fact, in a perfectly sound eye this solution excites violent irritation of the conjunctiva, and it is quite possible to produce an artificial catarrh by too frequent application of it. How then does it happen that the nitrate-of-silver solution has such a beneficent action in conjunctival catarrh ? The delicate bluish-white pellicle which covers the conjunctiva directly after the application is due to coagulation of the albumin of the cells in the upper layers of the epithelium by the nitrate of silver, so that these layers become opaque and die. The escharotic process acts like an irritant which increases the existing hypersemia. This not only gives rise to an increase of the annoyance suffered (exacerbation), but also induces a transudation under the eschar, so that the latter is loosened and finally cast off. But when this takes place the micro-organisms contained in the upper layers of the epithelium are thrown off with the eschar and so eliminated from the eye. The silver solution finds an extensive application not only in catarrh, but also in other affections of the conjunctiva. In regard to it the following hints may be laid to heart : (a) Many physicians apply weaker or stronger solutions according to the effect which is to be obtained, but we can always succeed with a 2-per-cent solution, since we have it in our power to regulate the effect by making a light or a penetrating application with the brush. (J) The applica- tion should not be made at night, because the secretion, which is poured out more abundantly after the application, would be retained in the conjunctival sac by the closure of the lids in sleep. For the same reason the eye ought not to be bandaged immediately after the application, (c) Corneal ulcers do not constitute a contraindication for making the application ; on the contrary, they furnish a direct indication for it, in case they prove to be catarrhal ulcers. Only still greater care than would otherwise be necessary must be taken to prevent the caustic from coming into contact with the cornea, {d) If the treatment of the conjunctiva with the silver solution is kept up too long (for some months or a year), there is produced little by little a dirty-gray coloration of the con- junctiva, which never afterward disappears. This phenomenon, called argyrosis or argyria,* is caused by the fact that silver is deposited in the form of an oxide or an albuminate in tlie tissues of the conjunctiva (in its elastic fibers), and can never afterward be removed. Argyrosis is produced even more readily by the constant instillation of the silver solution than by the application of the brush, since in the former case the excess of the solution is not removed by being washed off, but remains in the conjunctival sac. This coloration of the conjunctiva is also observed when the conjunctiva is constantly exposed to the action of silver dust, as occurs, for example, in many of those who work in silver. * Prom Hpyvpos, silver. 50 DISEASES OF THE EYE. In conjunctival catarrh, as well as in other affections of the conjunctiva, acetate of lead is also employed, partly as an astringent, partly as a mild caus- tic, and either under the form of a solution to be applied on compresses, by in- stillations, and by means of the brush, or under the form of an ointment. As long as the cornea is perfectly normal this remedy is without ill effect ; but as soon as a loss of substance (ulcer) exists in the cornea, there is formed, if the use of the remedy is continued, an intensely white, very disfiguring opacity at the site of the ulcer. This lead incrustation, as it is called, is caused by the impregnation of the tissues of the cornea with the lead salt, and can be re- moved from the cornea with difiiculty or not at all. For this reason it is best to employ the lead acetate as little as possible in the treatment of conjunctival diseases; the more so, because a sufficiency of other remedies is at our com- mand, with which we can accomplish the same results without danger. ' Bandaging the eye in catarrh, as in all diseases of the eye accompanied with profuse secretion, is to be avoided as much as possible, since by it the free exit of the secretion is obstructed. {i) Conjunctivitis Catarrlialis Chronica. 9. Symptoms. — In chronic conjunctival catarrh the changes objec- tively perceptible are on the whole but slightly pronounced. A mod- erate degree of redness of the conjunctiva exists either over the tarsus alone or in the region of transition also. The conjunctiva is smooth and not swollen ; it is only in old cases that hypertrophy with thick- ening and a velvety appearance of the conjunctiva is developed. The secretion is scanty and makes itself chiefly apparent by a gluing to- gether of the lids in the morning. The whitish scum often found at the angles of the lids is produced by the lachrymal fluid being beaten up with the secretion of the Meibomian gland into a sort of foamy emulsion, as a result of the frequent blinking of the lids. The con- stant moistening of the skin at this spot often leads to the formation of excoriations. In many cases the secretion, instead of being in- creased, seems even to be diminished. In view of the fact that there is little or no increase in the secretion, several authors call many of these cases not by the name of chronic catarrh, but by that of hyper- £emia of the conjunctiva. In proportion to the insignificance of the objective symptoms, the greater is the attention that has to be paid to the complaints made by the patient — in fact, the subjective symptoms are generally so charac- teristic that the diagnosis of chronic conjunctival catarrh can easily be made from them alone. The discomfort of the patient is usually greatest at night. The heaviness of the lids, scarcely noticeable in the daytime, becomes at night so marked that the patients have difficulty in keep- ing the eyes open ; they have the feeling of being sleepy. A very an- noying sensation of there being a foreign body — like a speck of dust- in the eye, is produced by the scanty secretion which remains in the conjunctival sac in the form of mucous filaments, and if these fila- DISEASES OF THE CONJUNCTIVA. 5j ments lie upon the cornea the sight is interfered with, or rainbow colora make their appearance about a candle flame when looked at. Further unpleasant sensations of various kinds are described, as, for example, that the eyes burn and itch ; that they are dazzled by the light ; that, moreover, they are tired out quickly by working ; that they blink often, etc. In the morning the eyes are somewhat stuck together, or a little yellowish dried secretion is found to have collected in the inner angle of the eye. In other cases there exists an annoying sensation of dryness, and the eyes can be opened only with difficulty, the patient, at the same time, having the feeling as if the lids were stuck to the eye- ball because of the lack of moisture [catarrhus siccus). These troubles, so various in their nature, do not always by any means bear any defi- nite relation to the objective condition. We see the conjunctiva quite intensely reddened in many people without their complaining in the least ; while in others, who do nothing but annoy the physician with their expressions of discomfort, there are often scarcely any changes perceptible in the conjunctiva. Course. — Chronic conjunctival catarrh is one of the most frequent of ocular diseases, chiefly affecting adults, and especially persons some- what advanced in age. In old people it is almost the rule to find a light grade of chronic conjunctival catarrh, which is denominated senile catarrh. The duration of conjunctival catarrh is ordinarily a long one; many people suffer from it for a great part of their lives. The disease can lead to cowplications which in part produce irreparable changes. Among the most frequent complications is inflammation of the edges of the lids {Mei}]iaritis), resulting from the frequent moistening of the palpebral margins by the copiously secreted tears. As a further con- sequence of this wetting with the tears, the skin of the lower lid is attacked with eczema, or it becomes rigid and contracted, so that its free edge is no longer in perfect apposition with the eyeball. As a result of this the punctum lacrimale no longer dips into the lacus lac- rimalis, so that the transportation of the tears into the lachrymal sac is impeded, the epiphora increased, and thus again a still further injuri- ous reaction upon the character of the skin is produced. In this way there is formed a vicious circle, which leads to a constantly increasing depression of the lower lid (ectropion). This outcome is still further promoted by the circumstance that the patient keeps wiping away the overflowing tears, and thus makes stroking movements from above downward, by which the lower lid is drawn down. If the contraction of the skin of the lids which have been moistened by the tears is more pronounced in the horizontal direction, blepharophimosis is developed (§ 112). Lastly, small ulcerations of the cornea are among the fre- quent products of catarrh. Etiolo^.— The causes which lie at the foundation of chronic catarrh are— 1. A preceding acute catarrh, which, instead of healing com- 52 DISEASES OP THE EYE. pletely, passes into the chronic stage. 2. General injurious influences of various kinds. Chief among these is bad air, vitiated by smoke, dust, heat, the presence of many people, etc. Workers in factories where dust prevails largely, waiters in inns that are filled with smoke, etc., very frequently suffer from chronic conjunctival catarrh. Going late to bed, being up at night, and the immoderate use of alcoholic beverages are additional predisposing factors. Persons who already suffer from chronic conjunctival catarrh find that the latter is made considerably worse after the action of any injurious influence of this sort — for example, after an evening spent at the theater or in a smoky place. So also the constant action of wind and bad weather frequently causes catarrh in farmers, coachmen, etc. For the same reason, too, eyes which are very prominent (goggle eyes), or whose lids are re- tracted (lagophthalmus), are attacked by catarrh, because they are too little protected against the air. The effect which constant contact with the air exerts upon the conjunctiva is best shown in ectropion, where the conjunctiva tarsi, as it lies bare, becomes very much red- dened and thickened, and velvety or even covered with large promi- nences. The conjunctiva bears continued exclusion from the air as little as it does constant contact with it, on which account chronic catarrh sets in when bandaging of the eye is kept up for a long time. 3. Excessive straining of the eyes, especially in hypermetropic or astig- matic persons can result in chronic catarrh. 4. Local injurious influ- ences. Here belongs irritation of the conjunctiva by foreign bodies lodging in the conjunctival sac, among which, using the term foreign bodies in the wider sense of the word, are to be reckoned cilia which are turned in toward the eye. In most cases the local injurious influence consists of some other disease of the eye, that induces catarrh as a sequela, as, for example, blepharitis or infarction of the Meibomian glands. Accumulation of the tears, as a result of blen- norrhoea of the tear sac, or because the punctum lacrimale does not dip properly into the lacus lacrimalis, is a frequent cause of catarrh, so that we should never forget to look for an affection of the tear passages in unilateral catarrh. We say unilateral, for catarrh produced by local causes is distinguished from that due to general injurious in- fluences in this respect, that the former is very frequently unilateral, while in the latter, from the nature of the case, both eyes are generally affected. Therapy. — It is clear that treatment must first of all pay regard to the causal factor by regulating in a suitable way, as far as is compatible with the patient's calling, the general conditions under which he lives and by removing all local causes of catarrh that may be present, etc. For the treatment of the conjunctiva itself we first employ, as we do in acute catarrh, the nitrate of silver, which is used either for applica- tion by the brush (in 3-per-cent solution) or for instillation (in i- to -^- DISEASES OP THE CONJUNCTIVA. 53 per-cent solution). We make use of it in those cases only in which the catarrh is accompanied by rather abundant secretion and by re- laxation of the conjunctiva— that is, in periods of acute exacerbation, such as frequently occur in the course of every chronic catarrh and use it, furthermore, when hypertrophy of the conjunctiva has already set in. Otherwise we succeed better with astringent coUyria, which the patient can himself instill. The most usually employed of these are: The collyrium astringens luteum * or tinctura opii crocata, which are not ordinarily prescribed undiluted, but mixed with an equal quan- tity of water ; lapis divinus f and sulphate of zinc, both in ^- to 1-per- cent solution; also alum, tannin, boric acid,, and other astringents. The order in which these collyria are here arranged about corre- spond to their gradation in activity from the strongest to the mildest. They should be instilled once or twice a day, but not 'at night. So many of them are enumerated, because it is good to have a pretty large number to select from, since, if the catarrh is of long duration, a change will have to be made pretty often in the remedies. Every remedy, if too long applied, loses its activity, since the conjunctiva grows accustomed to it. For the sticking together of the lids, as well as for any excoriations that may be present, an ointment of white precipitate (|- to 1 per cent) may be rubbed upon the closed lids at night before going to bed. (c) Conjunctivitis Folliciilaris. 10. Follicular catarrh is characterized by the presence of follicles. These are small round granules of about the size of a pin's head, which lie in the region of transition of the conjunctiva. They are of a pale, translucent aspect and puff up the conjunctiva in the form of small eminences. Either a few follicles only or many are present; in the latter case they are ordinarily arranged in rows like the beads of a rosary. Mici'oscopic examination shows that the follicles, as well as * This collyrium, called also Horst's eye water, is at present no longer official in most countries; yet it is of the greatest service, and in many oases can be re- placed by no other. According to the new (seventh) edition of the Austrian Phar- macopoeia, which went into effect on the 1st of January, 1890, it is to be prepared in the following way : Take of ammonium chloride 50 centigrammes and zinc sulphate 125 centi- grammes, dissolve in 200 grammes of distilled water, and add a solution of 40 centi- grammes of camphor in 20 grammes of dilute alcohol, and 10 centigrammes of saffron. Digest for twenty-four hours with frequent agitation, and filter. Romershausen's eye water, which is also frequently employed in chronic oph- thalmic catarrh, consists of a mixture of aqua foeniculi and tinctura fceniculi. [f Or aluminated copper; a preparation made by fusing together 33 parts each of copper sulphate, potassium nitrate, and alum, and adding a mixture of 2 parts each of camphor and alum. — D.] 54: DISEASES OP THE EYE. the so-called trachoma granules, consist of a circumscribed accumula- tion of adenoid tissue (Fig. 26, T). Follicles are most frequently observed in youth, and can accompany both acute and chronic catarrh. Their significance consists in the fact that when follicles are present the malady is a protracted one. In chronic cases, the follicles remain stationary in the conjunctiva for a series of years. The follicles ultimately disappear without leaving a trace behind ; the disease, therefore, in spite of its long duration, has a good prognosis, in that it is cured without leaving any sequelee. In this particular, follicular catarrh is essentially distinguished from tra- choma, which in its external appearance bears a great resemblance to it,' but which, however, always leads to permanent changes in the con- junctiva. The etiology of follicular catarrh has not up to this time been established. By some, contagion, by others, miasm (vitiated air), has been assigned as a cause of the disease, without any certain proofs being brought for either one view or the other. The malady is found with especial frequency in schools, boarding establishments, etc., in which often many scholars are attacked by it at the same time. In many of these people the disease exists in an entirely latent way, as, in spite of there being a considerable number of follicles, the conjunctiva is not reddened and causes no sort of discomfort, so that the affection is first discovered by the physician's examination. The treatment is the same as we are accustomed to employ against conjunctival catarrh in any case. By means of it the inflammatory symptoms on the part of the conjunctiva and along with them the annoyance suffered are relieved ; but the follicles themselves generally remain obstinately stationary. In order to make them disappear, the best thing is to rub a lead ointment (acetate of lead 0.1-0.2 grammes, fatty matter 5 grammes) into the conjunctival sac. In doing this it must not be forgotten that the presence of corneal ulcers very strongly contraindicates the use of a lead ointment. Cases in which the folli- cles exist without causing any annoyance are best left without any treat- ment, As in catarrh of all kinds, so especially in follicular catarrh, living in fresh, pure air is to be recommended. II. CosrjuNCTivms Blennorrhoica Acuta. 11. Acute Mennorrhcea* is an acute inflammation of the conjunc- tiva, which originates in contagion from gonorrhoeal virus, and whose copious purulent secretion is likewise contagious in its action. The carriers of the contagion are micro-organisms, namely, the gonococci discovered by Neisser. They bear this name because they also occur in the secretion of gonorrhoea. The gonococci are found both in the * Prom fi\4yya, mucus, and (i4a>, I flow. DISEASES OP THE CONJUNCTIVA. 55 pus secreted by the conjunctiva and also in the most superficial layers of the conjunctiva itself. They are mostly arranged in pairs, as diplo- cocci, and as a rule lie together in heaps. Fig. 23 shows a specimen taken from the secretion of an acute blennorrhosa. In it are seen the heaps of gonococci, partly free {a), partly upon and within the cells, which are either pus cells (b) or cast-ofE epithelial cells (c). Acute blennorrhoea occurs both in adults and in newborn infants — blennorrhoea adultorum and blennorrhoea neonatorum. (a) Blennorrhoea Acuta Adultorum [Conjunctivitis Gonorrlioicd). Symptoms and Course. — When infection has taken place, the disease breaks out after a certain period of incubation, the duration of which varies according to the intensity of the contagious action from a few hours up to three days. The lids grow red, become hot, and are swollen with oedema, generally to such an extent that the patient can no longer open them, and even the physician often has trouble in separating them far enough from each other to bring the cornea into view. The conjunctiva of the lids and of the re- gion of transition is intensely reddened and greatly swollen. The swelling is produced by an abundant cellular infiltration of the conjunctiva, which is consequently tense, and has a granular, uneven surface. This feature of acute blennorrhoea serves to dis- tinguish it from catarrh, in which even in 5 ' . . Fig. 23.— Secretion of Acute the severe cases the swelling is rather of a blenngerhiea with gonococci. serous nature, and hence the conjunctiva is yielding and has a smooth surface. The conjunctiva of the eyeball shows a like swelling, which stops short at the corneal margin, so that a raised wall is thus formed about, the more deeply placed cornea (chemosis). The secretion produced by the conjunctiva is like meat juice— that is, it is a serum which is colored red by admixture with blood, and in which float some flakes of pus. The eye is uncommonly sensitive to contact, the lymphatic gland in front of the ear is swollen, the patient has slight fever. Ordinarily it takes from two to three days for the disease to mount from its initial point to the pitch just described, and at this pitch it is maintained for two or three days more. This period is designated as the first stage, or stage of infiltration. Succeeding this as a second stage is that of pyorrlma. The swelling of the lids gradually dimin- ishes, a fact which we recognize principally by means of the return of the small wrinkles of the skin of the lids, and the tense infiltration of 56 DISEASES 0¥ THE EYE. the conjunctiva slowly retrogrades. Simultaneously with this there be- gins a very profuse secretion of pus, which trickles out continually from the palpebral fissure ; hence the name pyorrhcea, or flow of pus. In the further course of the disease the swelling of the conjunctiva keeps on constantly diminishing, the eye, in many cases, returning to the normal state within the next four or six weeks. In most cases, how- ever, a condition of chronic inflammation of the conjunctiva remains, which is designated as the third stage of the disease, the stage of chronic Uennorrhma. In this period the lids are no longer swollen. The conjunctiva is reddened and thickened, especially upon the tarsus, where its surface looks uneven, granular, or velvety. The fold of tran- sition forms an ungainly swelling; the conjunctiva of the eyeball, which shows hypereemia only, is the least changed. After this state of conjunctival hypertrophy has abated, a process which usually takes months for its accomplishment, there usually remain slight, but perma- nent cicatrices of the conjunctiva. The description here given corresponds to cases of most frequent occurrence, which are those of medium intensity. In addition, both light and also very severe cases of the disease come under observation which exhibit rather different features. In the light cases, which we are accustomed to call suiacute hlennorrlima, all the inflammatory changes are less, and the changes are limited chiefly to the conjunctiva of the lids. Such cases are frequently not to be distinguished with certainty by their external aspect from violent catarrh. The diagnosis can be rendered certain by the microscopic examination of the secre- tion, since by it the presence or absence of gonococci is demonstrated. In the severest cases, the infiltration of the conjunctiva is so great that the latter in places appears no longer red, but grayish-yellow, be- cause, as in diphtheritic disease of the conjunctiva, the vessels are com- pressed by the bulky exudation, and the conjunctiva is thus rendered anaemic. The conjunctiva forms about the cornea a tense grayish-red wall. Quite often the surface of the conjunctiva is found to be cov- ered with a clotted exudate, or croupous membrane. The most dreaded complication of acute blennorrhoea is the involve- ment of the cornea, by which, in many cases, incurable blindness is produced. At first the cornea becomes dull upon its surface and cov- ered with a slight difiused opacity. Then circumscribed infiltrations of grayish color make their appearance, which soon become yellow and break down into ulcers. These infiltrations may be situated at the margin of the cornea, and give rise to speedy perforation of the latter. This is a comparatively favorable result, as, after the perforation has taken place, the purulent infiltration of the cornea is not rarely brought to a standstill, and so a portion of the cornea is preserved. But it can also happen that the mprginal infiltrations become rapidly confluent, and unite into a yellow ring surrounding the entire cornea (a so-called DISEASES OF THE CONJUNCTIVA. 57 annular abscess). In that event the cornea is lost, for this ring soon spreads over the entire cornea and destroys it. In other cases the purulent disintegration occurs first in the middle layers of the cornea. A rare and peculiar form of involvement of the cornea occurs, in which the latter, without becoming noticeably opaque, melts away, as it were, like a piece of ice in the sun, until it has disappeared altogether, with the exception of a narrow portion of its rim. When, in one way or an- other, the cornea has gone either entirely or in part to destruction, cicatrices are formed with incarceration of the iris, or pauophthalmitis itself may be produced. Since these sequelae are observed after every destruction of the cornea, even when due to other causes, they will find detailed description under the diseases of the cornea. Involvement of the cornea is so much the more to be expected, the severer the blennorrhcea, and, in particular, the more pronounced the participation of the conjunctiva bulbi in the inflammation. In the severest cases with tense chemosis the cornea is always affected, and is, as a general thing, irretrievably destro3'ed. In the cases of moderate severity, when the chemotic swelling of the conjunctiva is less pro- nounced and especially is less hard, it is usually possible to preserve the ' cornea, either entirely or in great part, inasmuch as the ulcers that de- velop, even if they are attended with perforation, are of but small size. In the lightest cases, where the process is limited to the palpebral con- junctiva, there is, on the whole, little danger to the cornea. The severer the course of the inflammation, the earlier the involve- ment of the cornea sets in; in violent cases, the cornea is already clouded by the second or third day. Sometimes corneal ulcers are not developed until late in the disease, when the blennorrhrea is already well on the retrograde path. These late affections of the cornea are not very dangerous, and it is generally possible to check them readily. The prognosis of the disease results from what has been said, it being essentially founded upon the condition of the cornea. This is dependent upon the intensity of the inflammation of the conjunc- tiva bulbi, in accordance with which, therefore, the prognosis must be made. Etiology.— Acute blennorrhcea is produced simply and solely by infection. The poison can be introduced into the eye from the genitals directly, generally by an individual (whether man or woman) affected with gonorrhoea, touching the eyes with unclean fingers after these have been in contact with the genitals. The infection, however, can also come from an eye affected with blennorrhcea. If, for instance, one eye is already diseased and is affected with profuse suppuration, the other eye also can be infected by a transfer of the secretion to it. An individual with an eye diseased with bleunorrha?a can infect the persons who are nursing him or any others who may share his 58 DISEASES OP THE EYE. room, so that we sometimes see an entire family stricken with this baneful malady. Therapy. — By proper prophylaxis infection by acute blennorrhcea can be prevented, a matter to be so much the more considered because, when the disease has once broken out, an unfortunate result can not always be averted. It is the physician's duty to call the attention of every man with gonorrhoea, and also of every woman with a vaginal discharge, to the danger of infecting the eyes, and to urge upon them strenuously the requisite cleanliness. If the eye is already attacked with acute blennorrhcea, care must be taken to keep the othfr eye from being infected by it and also to keep the disease from being transferred to persons in the vicinity. The protection of the second eye which has not as yet been involved in the disease is best effected by a bandage which is applied in the following manner : The palpebral fissure is first closed by means of some narrow strips of sticking plaster applied in a vertical direction. Then the hollow about the eye is filled up with cotton, and the whole is covered by a flap of linen pro- vided with adhesive-plaster strips, which is carefully attached all round the margins of the orbit. In order to secure it better, the edges of the flap and the adjacent skin may further be coated with collodion. To prevent the spread of the disease to those in the neighborhood of the patient, the greatest cleanliness must be inculcated both upon him and upon the persons attending to him ; they must always cleanse the hands after touching the affected eye, and must remove, or, best of all, burn, all materials that have been used for cleansing the eye (pieces of linen, cotton, etc.). The treatment of the disease itself consists principally in a careful and frequently repeated cleansing of the eye from its profuse secretion. We may employ for this purpose weak antiseptic solutions (solution of corrosive sublimate, 1-4,000, or of potassium permanganate). If the great swelling of the lids does not permit the palpebral fissure to be properly opened, and thus makes cleansing impossible, the palpebral fissure must be fully widened by a section made with the scissors at the external angle of the lids (canthoplasty ; see § 168). This section has the further advantage of diminishing the pressure which the much- swollen lids exert upon the eyeball. In the first stage of the disease we combat the inflammation by iced compresses, and also by the application of leeches (six to ten in number) to the temple. In the second stage brushing the conjunctiva with nitrate of silver is the best means for making the swelling of the conjunctiva and the profuse secretion rapidly disappear. The appli- cation of the brush must not, however, be begun until the tense swell- ing of the conjunctiva has given place to a soft, succulent condition ; there should no longer be any membranous deposit, any grayish infil- trated spots upon the conjunctiva. The application should be made DISEASES OF THE CONJUNCTIVA. 59 with a two-per-cent solution, but quite freely, and must be repeated twice a day as long as the profuse secretion is still present. The pres- ence of ulcers of the cornea furnishes no contraindication to the use of nitrate of silver. As soon as, in the third stage, the inflammatory symptoms and the secretion also have nearly disappeared and the thickening of the con- junctiva is the only thing that still remains to be removed, we exchange the silver solution for copper sulphate. This is applied by whittling a crystal of the substance down to a smooth, rounded extremity (copper pencil or bluestone) and stroking with it once or more the conjunctiva of the everted lids. Then the lachrymal fluid, which is tinged blue by the copper salt dissolved in it, is dipped up from the conjunctiva with a pledget of cotton ; otherwise the pretty concentrated copper solution would come into contact with the cornea and irritate it greatly. The ap- plication of the bluestone is much more painful than that of the silver solution, but acts more energetically, and hence we get quicker results with it ; but this treatment is permissible only if the cornea is either quite sound or has ulcers already in process of cicatrization, and not if there are fresh ulcerations of the cornea, which are still coated with pus. The treatment of ccmplications involving the cornea is conducted according to the rules (§§ 34, 36) for purulent keratitis. If very severe, all treatment proves powerless to preserve the cornea, so that we must confine ourselves to attempting to avoid the more remote evil consequences of destruction of the cornea, like panophthalmitis or the formation of staphyloma, and to obtain a flat cicatrix. It is now established beyond doubt that acute blennorrhoea is developed by the direct transfer of virulent pus to the conjunctiva. The earlier view, which explained the connection between gonorrhoea and ophthalmia by looking upon the latter as a sort of metastasis of gonorrhoea, has now no longer any adherents. Nevertheless, cases have been described recently (by Ricord, Roos- brock, HaltenhoS, Rilckert, Armaignac, and others) in which a conjunctival inflammation of a lighter kind is connected with a gonorrhoea in the way of metastasis, just as arthritis and iritis sometimes complicate a gonorrhcEa. This metastatic mode of origin is to be understood by supposing that the gonorrhoial poison has got into the circulation, and is exciting inflammation in remote organs which have a predisposition for this poison. A conjunctivitis originat- ing in this way is said to show the characters, not of a blennorrhoea, but of a violent catarrhal conjunctivitis, and the injection of the eyeball is like that which occurs in scleritis. In any case, we shall have to be uncommonly careful in making the diagnosis of such a metastatic gonorrheal conjunctivitis, since light cases of conjunctivitis can also develop from direct infection with gonor- rhoeal secretion, in case the gonorrhoeal poison has been weakened by various circumstances. (See infra, the investigations of Piringer.) As a gonorrhoea of the urethra can by metastasis excite a conjunctivitis, so also conversely oases have been observed in which a gonorrhoeal arthritis, where gonococci have been demonstrated to exist in the pus, has arisen by way of metastasis from a blen- norrhoea of the conjunctiva (Deutschmann and others). 60 DISEASES OP THE EYE. The secretion containing gonooocci is usually brought into the eye by means of dirty fingers. Sometimes, however, a direct transfer from the diseased mu- cous membrane to the sound one is observed ; for example, when a drop of secre- tion spurts into the eye of the physician or the attendant while cleansing geni- tals that are affected with gonorrhoea, or even when cleansing the eye of a patient affected with blennorrhoea. For this reason the old method of cleansing blen- norrhoeal eyes by means of a glass syringe has been given up in most ophthalmic clinics, as it endangers both the eye of the patient and the eyes of the corps of attendants. Furthermore, in the treatment of such patients, physicians and at- tendants ought always to use protective glasses (large, colorless coquille glasses). If, in spite of this, any secretion does spurt into the eye, the latter must im- mediately be very thoroughly washed out; then a couple of drops of two-per- cent nitrate-of-silver solution instilled, and subsequently for some hours cold compresses placed upon the eye. I have repeatedly seen cases in which a patient, because of a mild conjunc- tival catarrh, washed his eyes in his own urine (a popular remedy among the laity in many places); as he had gonorrhoea, he acquired an acute blennorrhoea. Acute blennorrhcea, moreover, has been seen to originate from the use of an- other household remedy— that is, from the practice of laying upon the eye a piece of placenta, which in this case came from a woman affected with gonor- rhoea. If one eye is already infected, the transfer to the other is often brought about by the secretion of the diseased eye flowing over the bridge of the nose into the sound eye during sleep. Furthermore, the secretion can be transferred from the eye affected with blennorrhcea to the sound one by the finger, the water used for washing, the sponge, the handkerchief, etc. For these reasons the sound eye should be bandaged. If there is ground for suspecting that in- fection has already taken place, we can endeavor to prevent the outbreak of the disease by instilling a two-per-cent solution of nitrate of silver before applying the bandage. In order that the patient may see with the bandaged eye, we can insert a watch glass in an aperture which v^e make in the middle of the bandage. The transfer of blennorrhoea from an eye affected with the latter to the eyes of other people is likewise not rare. It occurs most frequently in children who are affected with blennorrhoea neonatorum, and thus infect their mothers, nurses, etc. In the Vienna Foundling Asylum, during the years 1812 and 1813, there were, for every hundred infants affected with blennorrhcea, more than fifteen nurses so affected, who had acquired their eye disease from the in- fants. I have seen a whole family infected with blennorrlioea by a child hav- ing blennorrhoea neonatorum, and thus plunged in the greatest misery. Great caution on our own part, therefore, and, what is more important, careful instruc- tion of the laity are here imperatively required. "We sometimes also observe acute blennorrhaa in small girls of the age of two to ten years, who at the same time are troubled with a vaginal discharge (Arlt). Here are we still dealing with contagion from a virulent vaginal catarrh ? or is the vaginal discharge of these girls a benign catarrh caused by scrofula, anaemia, and the like ? In some of these cases it has been possible to prove the origin of the vaginal blennorrhcea. The children have acquired the latter from their mothers or from other women about them, who were suffering from virulent vaginal catarrh, and had transmitted the latter by soiled clothes, sponges, baths, etc., to the children (Hirschberg). In other cases, the children had been DISEASES OP THE CONJUNCTIVA. gi raped by individuals affected with gonorrhoea. Here, therefore, we are dealing with a pure vagina! gonorrhoea in the children, and, accordingly, it is possible in such cases, too, to demonstrate the presence of the gonococcus both in the secre- tion of the. vagina and in the conjunctiva as well (Widmark). But it would be going much too far to regard the vaginal discharge in little girls as true gonor- rhoea in all cases in which infection of the conjunctiva results from the dis- charge. It seems to me probable that even a non-virulent, simple catarrhal secretion of the vagina is in position to excite an inflammation of the conjunc- tiva, which in this instance runs a less severe course, and exhibits the character of a mild (subacute) blennorrhoea. The distinction from a true blennorrhcea could be made in this case only by the microscopical examination of the secre- tion for gouococci. The interesting researches of Piringer have instructed us in regard to the relation letween the infective material and the ophthalmia produced hy it as he has made a great number of intentional transfers of virus (generally in the eyes of people already blind, who were paid for the experiment). He found that the period of incubation is of shorter duration in proportion as the blennor- rhoea which the inoculated material produces is more violent. The infective power of the secretion is weakened by various influences, as by dilution with water— by dilution to the one-hundredth part any secretion can be rendered inert— or by drying. Secretion that has been dried upon a piece of linen loses its activity after thirty-six hours. Preserved like vaccine, it remains infective for sixty hours. In proportion as the virulence of the infecting secretion is weakened, the period of incubation increases in length and the inflamma- tion excited grows milder. The differences that we observe in the grades of blennorrhoea can therefore be referred to the fact that the source of infection supplies secretion of different degrees of virulence, and this virulence is, more- over, still further modified by the immediate circumstances attending the process of infection. That the lymphatic gland in front of the ear should swell up in acute blennorrhoea is a fact that accords with the virulent character of the latter; sometimes even suppuration of this gland has been observed (bubo prscauricularis). The purulent inflammation of the cornea, which so often complicates the blennorrhcea, is to be referred to infection of the cornea by the secretion which constantly bathes the latter. Since the secretion collects most of all in the gutter lying at the rim of the cornea, between the latter and the steep slope of the chemotic conjunctiva, the purulent infiltration most frequently begins here, too. The dense infiltration existing in this chemotic wall of conjunctiva is to be regarded as a second factor in the production of corneal trouble. This leads to obstruction of the circulation in the marginal loops of the cornea, and thus interferes with the nutrition of the latter. Hence, the more pronounced and the more tense the chemosis, the more confidently is an affection of the cornea to be anticipated. It is in harmony with this fact that, in cases where the chemo- sis is unequally great, we often see the involvement of the cornea take place first at that portion of the corneal rim where the chemosis is the greatest. Since infection of the cornea is certainly very greatly favored by the exist- ence of gaps in the epithelium of the latter, we must avoid injuring the epi- thelium of the eye by carelessness in cleansing. If acute blennorrhoea happens to affect an eye which is covered with pannug the latter will afford the cornea a secure protection against suppuration. Nay, more, it is often apparent, after the violence of the inflammation has passed, 62 DISEASES OP THE EYE. that the pannus has cleared up considerably, so that- in cases of old pannus inoculation with acute blennorrhoea has been designedly performed. The fact that acute blennorrhoea is produced by micro-organisms would lead us to expect that disinfectant substances would be the best remedies in the treatment of it. Nevertheless, it has been shown that nitrate of silver far sur- passes the disinfectants proper for this purpose. It is, in fact, specially poi- sonous to the gonococcus, and, moreover, effects its removal mechanically by reducing to an eschar, and thus leading to the exfoliation of, the superficial layers of epiihellum containing this microbe. In the first stage of the disease we may make use of scarifications of the chemotic conjunctiva in severe cases. (5) Blennorrhma Neonatorum. 12. This disease is identical with the blennorrhcea of adults. More- over, it owes its origin to infection by secretion from genitals which are afEected with virulent catarrh. The infection occurs as a rule dur- ing parturition. In the passage of the child's head through the vagina, the eyelids are covered with the secretion of the latter, and this either penetrates immediately into the conjunctival sac through the palpebral fissure, or does so as soon as the child opens his eyes for the first time. Under these circumstances the disease breaks out as a rule on the sec- ond or third (rarely on the fourth or fifth) day after birth. In those cases in which the disease makes its appearance still later than this, the infection can not any longer be referred to the act of birth. It has then been brought about through subsequent infection by the vaginal secretion of the mother (as is readily possible, particularly if the child sleeps in bed with the mother), or the child has been in- fected by another child, as, for instance, not rarely happens in lying-in establishments and foundling asylums. The symptoms of the disease are the same as in the blennorrhcea of adults, except that they are in general less severe. For even when there are great swelling of the lids and very profuse purulent discharge, the part which the bulbar conjunctiva takes in the process is relatively small, and we rarely find great chemosis. Hence also the danger of suppuration of the cornea is not so great. It does indeed occur, and that often enough too, but only in those cases which are treated badly or not at all. If a case comes under treatment in season — that is, while the cornea is still intact — the latter can almost to a certainty be main- tained in a healthy state. Supposing this condition to be fulfilled, therefore, the prognosis can be stated as favorable. The treatment in the first stage consists in diligent cleansing of the eye ; when suppuration commences we begin with the application of a two-per-cent nitrate-of-silver solution to the conjunctiva. In cases with profuse secretion this must be done twice a day. The application should be continued until the cure is complete, as otherwise it is easy for the process to recur to a moderate degree. DISEASES OP THE CONJUNCTIVA. 63 In blennorrhoea of the newborn, prophylaxis plays an even greater role than in the blennorrhoea of adults. There is perhaps no other disease in which the rigorous carrying out of prophylactic treatment would afford more gratifying results than in blennorrhcea of the new- born, which might In this way be made to disappear almost entirely. The principle which lies at the foundation of prophylaxis is the avoid- ance of infection during parturition. To this end the vagina should be cleansed as well as possible by antiseptic injections directly before parturition, a procedure which is also advisable on other grounds. As soon as the child is born, the lids while still closed are to be wiped off carefully with a clean rag. While the first bath is being given the child's eyes should not be wet with the water of the bath. As soon as the child has been wrapped up after the bath, the eyes should again be cleansed with clean water and with a piece of cloth or cotton designed for this purpose expressly, and then a drop of two-per- cent silver solution dropped into each eye. By this procedure, which was devised by Orede, blennorrhoea of the newborn can be avoided almost to a certainty. Blennorrhcsa of the newborn belongs among the diseases of frequent occurrence. The majority of pregnant women have catarrh of the vagina with a mucous or purulent discharge. In the greater portion of these cases we have to do with a benign vaginal catarrh, in a smaller portion with a virulent catarrh (gonorrhrea). In individual cases the distinction between benign and virulent is diiScult or impossible, for which reason prophylactic treatment ought to be carried out in all cases. The frequency of ophthalmia among the children, before the introduction of prophylactic treatment, varied from one to twenty per cent in different lying-in establishments. Among these are comprised light and severe cases. In the former, ordinarily no gonococci are found in the secretion, although pneumo- cocci are often present (Parinaud, Morax); these cases are hence not to be regarded as blennorrhoea. Conjecturally these are the cases in which the mother has a benign catarrh of the vagina. Of the severe cases, those of blen- norrhoea proper, a certain number go blind on account of the failure to treat them in season, so that a very considerable number of cases of blindness are to be laid to the account of this disease. In the asylums for the blind of Germany and Austria, those who are rendered blind by blennorrhcea neonatorum form more than a third part of the whole number ; on the whole, those who are rendered blind in this way certainly constitute more than the tenth part of all living blind persons. The number of the blind in Europe is reckoned at more than three hundred thousand. If blennorrhcea neonatorum were made to dis- appear from the causes of blindness by universally carrying out a prophylactic treatment, there would be in Europe alone at least thirty thousand fewer blind people. That prophylaxis, as introduced into practice by Cred6, is actually efficient, is proved by the following data : Cred6 formerly had in the Lelpsic Lying-in Asylum on an average in the whole number of newborn 10.8 per cent of cases of blennorrhoea neonatorum ; after the introduction of his prophylactic method the number sank to 0.1 to 0.2 per cent. Others have similar favorable results 64 DISEASES OP THE EYE. to record. Unfortunately, up to the present time, the prophylaxis of blennor- rhcea has not been generally introduced by law ; it has merely been brought into use in lying-in establishments and also in the private practice of many physi- cians, while to the vast majority of children it is not applied at all. Credo's prophylactic treatment acts as a protection against infection during parturition only. Infection can, however, take place even earlier : children have been known to come into the world with a blennorrhoea already fully developed— in fact, with the cornea already destroyed. Furthermore, against subsequent infection by the vaginal secretion of the mother, or by other chil- dren, other measures will have to be adopted, among which great cleanliness is to be assigned the first place. In foundling asylums, infants infected with blennorrhcea should, be isolated from the rest, as otherwise infection will fre- quently take place. In the Vienna Foundling Asylum, during the years 1854- '66, no less than fourteen hundred and thirteen children were first attacked by blennorrhcea while in the asylum, and hence caught the infection in the latter. In infants after the subsidence of the acute inflammation, a chronic hyper- trophy of the conjunctiva (chronic blennorrhoea) develops much less frequently than in adults. On the other hand, after severe cases of blennorrhoea neona- torum, the conjunctiva, especially in the retrotarsal folds, often acquires a deli- cately cicatricial character, which remains for life. III. Conjunctivitis Tkachomatosa. 13. Trachoma, like acute blennorrhoea, is an inflammation of the conjunctiva, which originates by infection, and produces an infectious, purulent secretion. It is distinguished from acute blennorrhoea prin- cipally by its chronic course, in which is developed an hypertrophy of the conjunctiva, that forms the most characteristic symptom of tracho- ma. From the roughness of the conjunctiva, caused by this hyper- trophy, the disease has in fact received its name.* Symptoms. — The patients complain of sensitiveness to light, of lach- ryraation,and of sticking together of the lids; pain and visual disturb- ances are also often present. The examination of the eye shows that the latter is less widely opened, partly because of photophobia, partly because the heavy upper lid hangs lower down. After everting the lids, we see the conjunctiva of the tarsus and also that of the fold of transition reddened and thickened ; its surface at the same time has become uneven to a varying degree. These changes are to be referred to an hypertrophy of the mucous membrane, which occurs under two different forms. The first form consists in the development of the so-called papillee. These are elevations newly formed on the surface of the conjunctiva, which consequently appears velvety, or, if the papillee are large, ap- pears studded with coarse granules, with small nodules, or even with raspberry-like projections, the thickening of the conjunctiva being * Trachoma, from rpaxis, rough. DISEASES OF THE CONJUNCTIVA. g5 so great that the subjacent Meibomian glands are no longer Tisible through it. This kind of hypertrophy, which is called the papillary form, is found exclusively in the tarsal conjunctiva (Fig. 24 A). It is always most clearly pronounced on the upper lid, which therefore must be everted in making the diagnosis of the trachoma. The second form of hypertrophy is characterized by the presence of the trachoma granules. These are gray, translucent, roundish bodies. Fig. 24,— Schematic Section throcgh the Lids and Eyeball {A, in Recent, B, in Old Trachoma). A shows the way in which the two forms of hypertrophy of the conjuiictiva are distributed among the separate divisions of the latter ; B, the stage of sequelse of trachoma ; s, Sj, eyebrows ; o, Oj, furrow between the brow and the lid (sulcus orbito-palpebralis) ; d, d,, covering fold ; c, cilia in their proper position ; c,, cilia turned toward the cornea ; r, free border of the lid, wath the borders of the upper and lower lids running yjarallel and the pos- terior margins of the lids acute ; rj, free border of the lid, looking backward, and with its posterior margin rounded ; t, tarsus thickened by infiltration and covered w-ith the velvety conjunctiva tarsi ; /j, tarsus thinned (atrophic), "bent at an angle near its free extremity, and covered with smooth epithelium ; /, fornix with numerous trachoma granulations, 3', in the folds of the conjunctiva ; /„ fornix smooth, without folds (symblepharon posterius) ; p, thick pannus covering the upper half of the cornea ; pi, a shrunken pannus, extending over the whole cornea. which push up the most superficial layers of the conjunctiva in the form of a hemisphere, and are visible through the conjunctiva. On account of their translucent, seemingly gelatinous character, they have been likened to the eggs of frog-spawn or to grains of boiled sago. They are found principally in the folds of transition (/, Fig. 34 A), in which they are imbedded in such numbers that, when the lower lid is drawn down, the fold projects as a thick, rigid swelling, at the summit of which we sometimes see the granules arranged in rows like a string of pearls. In the conjunctiva tarsi the trachoma granules are less readily visible. They are smaller in this situation, and can not push the conjunctiva up because the latter is very closely adherent to the tarsus. Here, 5 66 DISEASES OP THE BYE. therefore, they generally appear as small, bright-yellowish points, which are situated deeply in the mucous membrane ; quite often, though, they are hidden from sight altogether by the development of the pa- pillae. Trachoma granules are often found in the semilunar fold, more rarely in other parts of the conjunctiva of the eyeball. This variety of proliferation of the conjunctiva is called the granuiar form. The two forms of proliferation of the conjunctiva sometimes occur separately. In the great majority of cases, however, both are found at the same time in the same eye, and so distributed that in the conjunc- tiva of the lids the most prominent feature is the proliferation of pa- pilla3, in the fold of transition it is the formation of trachoma granules (Pig. 24 A). The conjunctiva of the eyeball is, in light cases, un- altered, but when the irritation is more intense shows a coarsely reticu- late injection. The conjunctiva discharges a purulent secretion, the quantity of which is more abundant in the fresh cases and iu those attended with marked symptoms of irritation. In older cases, on the contrary, and in those which run a more sluggish course, it is very scanty. The disturbance of sight, of which many patients complain, is founded upon a complication affecting the cornea, and appearing under two different forms, pannus and ulceration, which very frequently occur together. Pannus * tracJiomatosiis consists in the deposition upon the surface of the cornea of a newly formed, brawny, vascular tissue, which pushes its way from the edge toward the center of the cornea. At the spot where the pannus is located, the surface of the cornea is uneven and studded with fine projections, and there is a gray, translucent, super- ficially situated, cloudy mass, which is traversed by numerous vessels. The latter spring from the vessels of the conjunctiva, which pass over the limbus and out upon the cornea, and, after arriving within the pannus, branch in an arborescent fashion. The pannus ordi- narily begins its development at the upper margin of the cornea, and cover first the upper half of the latter (p, Fig. 24: A). Quite often it terminates below in a sharp, straight, horizontal border. After- ward pannus develops at other portions of the corneal margin, until at length the entire cornea is covered by it. When pannus is pretty fully developed, the iris likewise participates in the inflammation (iritis). Disturbance of vision sets in as soon as the pannus has advanced into the pupillary area of the cornea — that is, in that region of the latter which lies directly opposite the pupil. If this region is entirely cov- ered by pannus, vision is reduced until it is limited to the recognition of large objects, or even to the mere ability to distinguish between light and darkness (quantitative vision). * Pannus, a cloth. DISEASES OP THE CONJUNCTIVA. g-. The ulcers of the cornea either develop at a spot that is otherwise normal, or they occur in connection with pannus. In the latter case they are found principally at the free border of the pannus, more rarely within the latter. Since their character agrees with that of ulcers of the cornea generally, a more detailed account of them will be given under the latter head {§§ 32 et seq.). Course.— This is of the following character : The hypertrophy of the conjunctiva gradually increases, growing steadily greater, until it has reached a certain height, which is not the same in all cases. Then it disappears again, step by step, while a cica- tricial state of the conjunctiva with contraction takes its place. In this way the trachoma is cured in the sense that the specific morbid process has come to an end. Nevertheless, the conjunctiva has not become normal again by any means ; on the contrary, it bears upon it lasting marks of the disease that has passed, namely, the signs of a cica- tricial contraction which, in many instances entails other, additional consequences, such as we will group together under the phrase " the state of sequelae of traclioma." The more considerable the degree which the hypertrophy of the conjunctiva attains, the greater and more strik- ing is the contraction of the latter, and the longer, too, is the duration of the disease, which in most cases is counted by years. The object of the treatment, therefore, must consist in checking the hypertrophy of the conjunctiva while it is developing, as thus both the duration of the disease is shortened and its evil consequences also are reduced to a smaller amount. In the conjujictiva tarsi, the beginning of the formation of cica- trices is betokened by a few narrow, whitish striaj (fine cicatricial bands), which we see emerging in the midst of the reddened and thickened conjunctiva. These striae gradually become more numerous and unite to form a delicate network, the meshes of which are occupied by red is- lands — that is, by those portions of the conjunctiva which are still hyper- «mic and hypertrophied. Little by little the cicatricial lines grow stead- ily bi'oader and the islands that they inclose steadily narrower, until at length that condition is produced in which the conjunctiva of the tarsus has become perfectly pale, thin, and smooth. The cicatricial condition of the conjunctiva corresponds in extent and intensity to the amount of hypertrophy that has preceded it. In those cases in which the hyper- trophy of the conjunctiva has attained a considerable height in certain spots only, it is also only at these spots that deep cicatrices remain after the trachoma has run its course, while those parts of the conjunc- tiva which were simply infiltrated, or were hypertrophic to only a very slight degree, return to the normal state. In the conjunctiva of the fornix the same conversion of hyper- trophy into cicatricial contraction takes place. Only, the external phenomena are somewhat different, in conformity with the different 68 DISEASES OP THE EYE. character of the conjunctiva in this situation. Here we do not see any whitish bands, but we find that the thick swellings which are formed by the hypertrophic fold of transition are becoming gradually thinner and flatter. Associated with this process, and proceeding with it step by step, is a condition of contraction taking place in the con- junctiva, a condition which steadily increases until even the folds that in the normal eye are present in the fornix are smoothed out and dis- appear (Fig. 24 B^ at/i). The conjunctiva has grown pale, and a deli- cate bluish-white coating is witness to the cicatricial character of its superficial layers. Pannus, provided that further changes, such as will be described later, have not occurred in it, is capable of complete retrogression, so that the cornea can reacquire its normal transparency. Ulcers heal, leaving behind them cloudy spots, the influence of which upon vision is dependent upon the degree of their opaqueness and also upon their situation within the pupillary area of the cornea. The morbid changes in the conjunctiva and cornea, which are characteristic of trachoma, vary so greatly in their intensity that it will be necessary to distinguish the cases into those that are light and those that are severe. In the lightest cases the hypertrophy of the conjunctiva is small and the cicatricial formation that succeeds it is correspondingly insignificant ; so much so, perhaps, that it may scarcely be possible any longer to make the diagnosis of trachoma, if some time has elapsed since it occurred. When once the cornea has become implicated, 'the case must always be characterized as severe. It must be remarked how- ever : (1) That the symptoms of irritation do not always by any means bear a fixed proportion in the objective changes ; cases with very great hypertrophy of the conjunctiva and thick pannus often running their course without inflammatory accidents and vice versa. (2) That similarly no fixed relation exists between the changes in the conjunc- tiva of the lids and those of the cornea. We see cases with very pro- nounced proliferation of the palpebral conjunctiva without pannus, and, on the other hand, cases with pannus and ulcers associated with a trifling affection of the conjunctiva. (3) In one and the same case the course is often very variable, in that sometimes intermissions or even spontaneous partial recoveries, sometimes relapses and exacerba- tions, occur. The latter are surely to be expected if, in a case that has been improved by treatment, treatment is too soon discontinued ; but it is noticed that they also occur without any known cause under ap- propriate treatment properly carried out. Thus, a suddenly occurring supplemental attack of pannus can in a short time annihilate the results of months of treatment. It is not only, however, with regard to the intensity of the morbid changes, but also with regard to the stviftness with which they take place that such great variety prevails, and the same is true of the as- DISEASES OP THE CONJUNCTIVA. 69 sociated symptoms of irritation, which are usually the more consider- able the more rapid the progress of the disease. In the majority of cases the disease sets in with moderate symptoms of irritation photo- phobia, lachrymation, pain— which augment with the increase in the objective changes. Not infrequently, however, trachoma develops so insidiously that for a long time those whom it has attacked are not aware of it. Such persons sometimes do not have their attention called to their disease until the pannus as it covers the cornea begins to disturb their sight. These cases belong as a rule to the granular form of trachoma. When the people living in barracks, schools, etc., that are infected with trachoma undergo medical examination, there is always found a number of inmates who do not complain of any troubles whatever and who regard themselves as perfectly healthy, while exam- ination shows in the folds of transition a very considerable develop- ment of trachoma granules. In contrast with cases running this in- sidious course are the cases of what is called amte trachoma. In these the disease begins with very violent inflammatory accessories; the 03dema of the lids, the great swelling of the conjunctiva, the profuse purulent secretion would almost lead us to imagine the case to be an acute blennorrhcea. The correct diagnosis can be made as a rule by our finding the conjunctiva studded with numerous trachoma granules. But if these are absent during the first days of illness, or if, because of the great swelling of the conjunctiva, they are not apparent, the subse- quent course of the disease may be the only thing that can clear up the nature of the latter ; which it does, since the hypertrophy of the con- junctiva, that is characteristic of trachoma, soon develops. Such acute cases occur chiefly during the prevalence of an epidemic of trachoma ; they are dangerous to sight not so much on account of pannus as of corneal ulcers, that make their appearance during the acute stage. 14. Stage of Sequelae of Trachoma. — It is only the lightest cases, or those that come under treatment early, that are completely cured. In other cases there are left sequelae, which are accompanied by a per- manent impairment of the eye. These affect either the lids and con- junctiva or the cornea. They are as follows : 1. Distortion of the lids with faulty disposition of the cilia. The distortion is produced by the cicatricial contraction of the conjunctiva and the tarsus, as a result of which the tarsus bends in such a way as to be convex anteriorly. This distortion is recognizable even from an inspection of the lids while in situ, from the fact that they bulge more than usual. It appears still more clearly on everting the lids, especially in the upper lid, in which the distortion is always more pronounced. We find the conjunctival surface of this lid traversed by cicatrices, among which one that is particularly striking is a cicatricial band which runs in the form of a narrow white line two or three millimetres above the free edge of the lid and parallel with it. Along this line 10 DISEASES OF THE EYE. there is a fnrrowlike depression produced by the drawing in of the conjunctiva and the tarsus. On everting the lids we feel that cor- responding to this spot there is an angular bend of the tarsus (^i, Fig. 24 B), which lies, therefore, in the neighborhood of the free border of the lid. From this bending of the tarsus the whole lid acquires a boat- like or bovvllike shape. The cause of the distortion of the tarsus lies partly in the cicatricial contraction of the conjunctiva ; for, as the conjunctiva grows shorter upon the posterior surface of the tarsus, it tends to bulge the latter forward. But the distortion is mainly produced by changes in the tarsus itself. The latter is as much the seat of inflammatory infiltra- tion in severe cases of trachoma as is the conjunctiva itself. It is hence increased in size and, when we evert the lid, we feel that it is thicker, wider, and at the same time less pliable, so that sometimes the eversion of the lids is rendered considerably more difficult. From such a state of things the experienced observer would infer that he has to fear a subsequent distortion of the tarsus with its consequences. The infil- tration and thickening of the tarsus are greatest near its lower margin, along the line at which the blood-vessels passing to the conjunctiva from in front perforate the tarsus (see page 39 and Fig. 21, rp). There is no doubt but that it is chiefly along these vessels that the in- flammatory infiltration makes its way from the conjunctiva to the tar- sus. Hence, cicatricial contraction, which succeeds the infiltration and which makes the whole tarsus thinner and narrower, is greatest at this spot and produces there an angular bending of the tarsus, correspond- ing to which is the cicatricial line that is seen running horizontally upon the conjunctiva tarsi, and the position of which accordingly agrees in general with that of the sulcus subtarsalis present in the normal lid. The immediate consequence of the distortion of the lid is an altera- tion in the position of its free border and of the cilia springing from it. In the upper lid the free border no longer looks straight downward, but downward and backward (inward). The internal margin of the lid, which in the healthy state is sharp, becomes rounded off (" worn down ") and is no longer to be recognized with distinctness (Fig. 24 B, rj), this being due partly to the way in which it is drawn by the contract- ing conjunctiva, partly to the pressure of the eyeball upon it. By the turning inward of the free border of the lid the direction of the cilia (ci) is changed, so that they now no longer look forward, but look downward and backward, and touch the surface of the cornea (trichi- asis). Another factor besides the distortion of the tarsus that con- tributes to this false position of the cilia, is the tension which the con- tracting conjunctiva exerts. This tends to draw the skin, and with it the cilia, over the free border of the lid and up upon the posterior surface. If the distortion of the lid progresses, the entire border of the lid DISEASES OP THE CONJUNCTIVA. n turns backward and eniropion is produced. In trichiasis and entropion alike tliere is a permanent condition of irritation, whicli is excited and maintained in tlie eye by the constant contact of the cilia with the cornea ; if this condition lasts any length of time, diseases of the cornea make their appearance as a consequence of the mechanical injury pro- duced by the cilia (see §§ 34 and 44). The opposite kind of anomaly of position of the lid— that is, its turning outward, or ectropion — also occurs as a result of trachoma. The cause of this is that the conjunctiva, when it is thickened and has un- dergone great proliferation, crowds the lid away from the eyeball ; the contraction of the muscular fibers of the orbicularis then sufBces to complete the eversion of the lid. This kind of ectropion is usually found only in the lower lid (see § 111). 2. Symblepharon Posteriiis. — When the cicatricial contraction of the conjunctiva reaches a high degree, the folds of the region of tran- sition flatten out completely ; the conjunctiva passes directly from the lid to the eyeball (/„ Fig. 24 B). If the lower lid is drawn down with the finger, the conjunctiva stretches tightly in the form of a vertical fold between the lid and the eyeball, and if the lid is drawn down still farther, the eyeball, being fastened tightly to it by the conjunctiva, must follow. This condition is characterized as symblepharon pos- terius (see § 23). In particularly severe cases the lower half of the conjunctival sac is reduced to a shallow groove between the lid and the eyeball. 3. Xerosis Conjtinctivm. — This condition develops when the con- junctiva, owing to excessive atrophy, loses its secretory functions. A steady diminution in the lachrymal secretions, which occurs at the same time, contributes to the production of the xerosis. Xerosis manifests itself by the following signs : The secretion, formerly copious, now be- comes steadily scantier and assumes a tough, sticky, viscid character. In conjunction with this, a feeling of dryness develops in the eye. Subsequently there appear on the conjunctiva tarsi several dry-lookiug places, to which the lachrymal fluid can not adhere any more than if they were smeared with grease. This condition tends to spread, until finally the conjunctiva may be aifected by it throughout its whole extent. The cornea, which as a rule has become partly cicatricial from previous pannus and ulcers, likewise suffers from the deficient moisten- ing ; its epithelium becomes thicker, epidermoid, dry upon the surface, and hence opaque. Thus is produced that melancholy condition which is called xerophthalmus and which forms the worst termination of trachoma; the eye is rendered incurably blind, is disfiguring to its possessor, and in addition keeps torturing him with a constant, very tormenting sense of dryness (see § 24, Xerosis Conjunctiva). 4. Corneal Opacities.— These are after-effects, both of ulcers of the cornea and of pannus. A recent pannus, it is true, can disappear com- Y2 DISEASES OF THE EYE. pletely by a process of resorption, so that the cornea reacquires its nor- mal transparency. But often further changes take place in the pannus, which render its complete disappearance impossible. Among them is to be reckoned in the first place (a) the transformation into connective tissue, which the pannus undergoes if it lasts for a long time. In this the same change takes place in the pannus as in tjie trachomatous conjunctiva, a portion of the round cells of which the pannus is com- posed growing into spindle-cells and finally into connective-tissue fibers. As a consequence of this the pannus becomes thinner, its sur- face grows smooth, the vessels with a few exceptions disappear, and at length the pannus is transformed into a thin membrane of connective tissue which covers the surface of the cornea and hardly admits of fur- ther resorption. In cases in which the pannus is quite thick and succulent and covers the whole cornea, {b) ectasia of the cornea some- times results. That is, as the tissue of the pannus, which is soft and abounding in cells, penetrates more deeply into the cornea, the tissue of the latter softens and gives way before the intra-ocular pressure (kera- tectasia e panno). Such a cornea never becomes perfectly clear again. The same thing is true, finally, of those cases in which (c) pannus is complicated with ulcers ; the regions which are occupied by the latter likewise have permanent opacities left upon them. Trachoma, then, is a disease which is distinguished by its duration, extending over years, and which in many cases renders those who are attacked by it half or wholly blind. If we add to this the fact that because of its infectious nature it is exceedingly apt to spread, we shall understand hovF, for those regions in which it is endemic, it is a veritable scourge. 15. Etiology. — Trachoma originates exclusively in infection pro- ceeding from another eye affected with trachoma. Infection takes place by transfer of the secretion ; contagion by means of the atmos- phere, the existence of which was formerly accepted, seems not to occur. In all probability the secretion owes its infectious character to a micro-organism, as to whose nature, however, investigations so far have led to no concordant results. Since it is the secretion alone that transmits the infection, the danger of infection, which any given case carries with it, is in direct proportion to the amount of the secretion ; the more profuse the latter, the greater being the danger to those in the immediate neighborhood of the patient. The transfer of the secretion from one eye to another generally takes place indirectly through the medium of the finger or chiefly through the medium of certain articles of the toilet, like sponges, towels, handkerchiefs, etc., which are brought into contact with the eyes. A special opportunity for this to occur is afforded when a pretty large number of people have their sleeping apartments in common, and so make common use, too, of the articles above mentioned. Hence, trachoma spreads most extensively DISEASES OP THE CONJUNCTIVA. ^3 in barracks, penal establishments, poorhouses, orphan asylums, board- ing schools, and indeed schools of all kinds, etc. Moreover, outside of such institutions the same factor asserts itself, since trachoma prefer- ably attacks poor people who live crowded close together and bestow little care upon cleanliness. Moreover, the fact that in many coun- tries the Jews are special sufferers from trachoma is to be attributed to the same cause. Trachoma, finally, varies in its geographical distribu- tion. It is most frequent in Arabia and in Egypt, which is regarded as its proper home (ophthalmia JEgyptiaca, Egyptian ophthalmia). In Europe it is much more extensively distributed in the east than in the west. Elevated lands (Switzerland, Tyrol) are almost entirely free from it, while it is very frequently found in the low lands (Belgium, Holland, Hungary, and the whole region of the lower Danube). Therapy. — The treatment of the trachomatous conjunctiva has a twofold object in view : on the one hand it seeks to do away with the inflammatory complications and the increase of secretion, which is asso- ciated with them; on the other hand, to further the disappearance of the conjunctival hypertrophy. In this way it is most likely that the process of shrinking in the conjunctiva will be restricted as much as possible, so as to avert the evil consequences resulting from its cicatri- cial contraction. We attain both objects by the proper employment of caustics, of which two are almost exclusively in use; nitrate of silver in two-per-cent solution and sulphate of copper in the form of a stick. The silver has the feebler action, and is therefore borne better ; cop- per, being applied in substance, has a correspondingly stronger cauter- ant action, but also causes more irritation. These remedies are, as a rule, applied once a day, it being only in severe cases that they are used twice a day. The indications for the two remedies are as follows : Ni- trate of silver is employed in all recent cases with violent inflammatory symptoms and gi-eat secretion. It can also be used when there are ulcers upon the cornea that are still in the progressive stage, if we take care that none of the solution comes into contact with the cornea itself. Copper sulphate is suitable for those cases in which the inflam- matory symptoms are small, and its chief use is in removing the hyper- trophy of the conjunctiva. For this purpose it acts much more ener- getically than the silver solution, and should therefore be used in preference to it in all those cases in which its application is allowable at all. Great inflammatory irritation, but most of all the presence of ulcers of the cornea in a state of active progress, contraindicate the use of the bliiestone. From these indications it follows that, as a rule, we treat a recent case with the silver solution until the inflammatory symptoms have disap- peared and the secretion has diminished. As soon as this has occurred —and several weeks are generally sufficient for the purpose— we replace the silver solution by bluestone. At any rate, we must avoid using 74: DISEASES OF THE EYE. the silver solution for too long a time on account of the argyrosis which may develop as a result of it. The copper is now to be used, the application of it being made stronger or weaker according to the degree of hypertrophy, and is to be kept up for months and even years, until every trace of hypertrophy has vanished and the conjunc- tiva has become free from congestion and smooth throughout. At first the application is made every day ; but when only slight remains of the hypertrophy exist, it is sufficient to make the application every other day, and subsequently every third day ; and at this stage, the milder act- ing alum pencil (a sliver of alum whittled down to a fine edge) may be substituted for the bluestone. Moreover, the application should be made less and less energetically all the time, until, finally, when the cure of the trachoma is complete, the application is entirely suspended. In these later stages of the disease we can instruct the patient how to evert the lid himself and touch it with the bluestone, so that he need not come so often to the physician. Or, we can prescribe for him an ointment of copper sulphate (one half to one per cent), which he himself can rub into the conjunctival sac. When there is gi'eat cicatricial con- traction of the conjunctiva the bluestone is not applicable at all, and must be replaced by ointments. A one- or two-per-cent ointment of white or yellow mercurial precipitate (the latter acts more energetically) may be rubbed into the conjunctival sac. In relapses with great in- flammatory irritation, such as often occur in the course of the treat- ment, the copper is always to be replaced for a short time by the silver solution. If, however, the symptoms of irritation are very violent, the silver solution itself can not always be borne, and must then be re- placed for some time by milder remedies, such as instillations or com- presses made with weak solutions of corrosive sublimate or boric acid. The ojjerative treatment of trachoma, which is now a good deal practiced, is indicated in cases in which very numerous granulations are present in the retrotarsal folds. Excision of the retrotarsal folds, which would be the most radical method, is to be rejected because it always causes great contraction of the conjunctiva. Much to be pre- ferred are those methods that remove the trachoma granules by ex- pression without destroying the conjunctiva. This may be done either by puncturing the granulations individually with a sharp knife and then squeezing them out (Sattler), or by drawing the retrotarsal folds out between the blades of Knapp's roller forceps. In the latter instrument each blade carries a fluted roller, and when the conjunctiva is drawn in between the two rollers, which fit closely into each other, the trachoma granules are squeezed out. Neither by these nor by any similar methods is an immediate or a radical cure of trachoma effected, since along with the larger granulations small ones in process of development are always present, which can not be removed, and which grow bigger afterward. Hence it is necessary DISEASES OP THE CONJUNCTIVA. 75 after the reaction produced by the operation has subsided to apply caustics in the usual way. But it must be conceded that in suitable cases the duration of treatment is considerably shortened by resort to these operative procedures. Keining's method of daily repeated friction of the conjunctiva with a l-to-2,000 sublimate solution is also efficient mainly owing to its mechanical effect — i. e., to its causing expression of the granules. The treatment of trachoma must be kept up until the hypertrophy of the conjunctiva is completely done away -with, as otherwise relapses are to be looked for sooner or later. The chief difficulty in the treat- ment lies in its great length, it often requiring many months for a com- plete cure. Those patients who have not the endurance or the means necessary for such a course, give up treatment as soon as their subjective troubles have disappeared, without, however, being completely cured. Then we commonly see them returning after some time with a relapse, which is often more severe than the disease for which we originally treated them. This lack of completeness in tlie treatment is the reason why the disease with many men drags on through their whole life. The treatment of complications affectitig the cornea is conducted on the principle that the affections of the cornea, caused by a conjunctival trouble, are best cured by the treatment of the conjunctival trouble itself. Hence, ulcers of the cornea when occurring in connection with trachoma are not combated directly, but have their cure brought about by means of applications made to the conjunctiva. The only limita- tion to this is that, where there are corneal ulcers in active progress, the silver solution is demanded and the bluestone, on the other hand, is contraindicated, and further, that contact of the caustic with the cornea should be avoided as far as possible. For the iiitis, which is not rarely associated with ulcers of the cornea, atropine in one-per-cent solution is instilled. In other respects, ulcers of the cornea are to be treated according to the rules which are in general applicable to them (see § 34). It must only be noted that bandaging, which is gener- ally indicated in the case of ulcers of the cornea, should be avoided as far as possible when trachoma is present, because by the closure of the eye the secretion is retained in the conjunctival sac, and thus both the conjunctival and the corneal troubles are aggravated. Panmts, in recent cases, disappears of itself, simply from applica- tions being made to the conjunctiva. If the pannus is unusually dense, it is allowable to make careful applications of the caustic to the pannus itself. Since pannus is often associated with slight iritis, atropine should be instilled from time to time, in order to keep the pupil dilated and prevent the formation of posterior synechia;. Very old pannus, which already is partly made up of connective tissue and has lost all but a few of its vessels, requires special treatment. Experience has shown that further resorption can be obtained in such a pannus by exciting a 76 DISEASES OF THE EYE. violent inflammation in it, and so producing an increased succulence and a greater rascularity. For this purpose we make use of the je- quirity treatment (De Wecker). We here employ a three- to five-per- cent infusion of jequirity, which is prepared by steeping the ground jequirity beans for twenty-four hours in cold water. With this infusion, which is to be prepared fresh every day, the conjunctiva of the everted lids is painted very thoroughly two or three times a day. The inflam- mation that is thus produced reaches the desired height on the second or third day, when the lids are reddened and are swollen with oede- ma, the conjunctiva is strongly injected and covered with a croupous membrane, and slight chemosis is often present. This inflammation we designate as jequirity ophthalmia. As soon as it has attained the height just described, the further application of the remedy is discon- tinued, as otherwise we should make the inflammation increase to the point where it would cause a necrotic disintegration of the conjunc- tiva and cornea. We now allow the inflammation to run its course, simply keeping the eye clean ; when the inflammation has completely subsided, the cornea is found to have gained in transparency as com- pared with its former state, and sometimes to a very considerable ex- tent. This very energetic treatment is adapted only to those old cases of trachoma in which the more pronounced symptoms of inflammation are wanting, the conjunctiva is in great part cicatricial, and the cornea is entirely covered by old pannus. Of the sequelcB of trachoma, trichiasis and entropion demand opera- tive treatment (see the section on Operations, §§ 167 and' 170). The symblepharon posterius, which is produced by the shrinking of the conjunctiva, is amenable to no treatment. Xerosis of the conjunctiva is also incurable, so that treatment must be limited to the amelioration of the patient's sufferings. To diminish the sense of dryness, frequent instillations of milk, glycerin, or mucilaginous substances (e. g., the mucilago seminum cydoniorum) may be made. For bad cases Rudin, in order to preserve the eyeball from desiccation, has advised refresh- ing the edges of the lids and stitching them together, so as to unite them throughout except for a small space in their middle. In addition to the foregoing measures for the treatment of tracho- ma, it is self-evident that care must be taken to keep the eye clean, for which purpose we may prescribe weak antiseptic solutions. The patient should have a nourishing diet ; he ought not to be kept in his room, but, on the contrary, should be made to go out as much as pos- sible in the open air and take exercise, and if necessary may be directed to engage in some light out-of-door work. With a disease of this infectious character, its dissemination should be checked by suitable prophylaxis. The physician must set a good example, and must cleanse his hands very carefully after touching a tra- chomatous eye. He must call the attention of the patient affected with DISEASES OP THE CONJUNCTIVA. YY trachoma to the infectious nature of his disease. He must teach him how to protect from infection the other eye, which may be still healthy, and how to avoid spreading the disease among those in his immediate neighborhood, his family, his fellow-workmen, etc. Per securing the latter object, the prime requisite is that the patient should have his own washing materi.als, linen, bed, etc., and should keep them for his own individual use. The prevention of epidemics of trachoma in public establishments, such as barracks and institutions and schools of every sort, constitutes an important duty of the officials in charge of such places. These offi- cials should take care that the members of their community have separate washing materials, linen, etc., for their use. They should be kept ap- prised of the presence of any trachomatous patients by means of fre- quent medical inspection, and, as soon as such a patient is found, he should be immediately removed from the community; for, where no trachomatous patient is found, no extension of the disease is possible. It was at the commencement of our own century that trachoma began to attract the attention of physicians to any great degree. It was then that the disease first showed itself as an epidemic among the European armies (ophthal- mia militaris). People were of the opinion that it had been introduced into Europe from Egypt (hence ophthalmia ^gyptiaca) by Napoleon I. For when the latter, in July, 1798, landed in Egypt with an army of thirty-two thousand men, most of the soldiers were very soon attacked by a violent ophthalmia, and these were supposed to have brought with them upon their return to Europe the disease which was formerly confined to Egypt. Subsequent historical re- searches, however, have shown that the disease had already been endemic in Europe since antiquity. Celsus mentions the disease, and gives a good de- scription of the roughness of the lids and the purulent discharge that it occa- sions. For treatment the ancients employed scarification of the conjunctiva, which is still to-day made use of by some, and which was accomplished both by means of various instruments and also by friction with fig leaves. From time immemorial, then, trachoma has existed in Europe as an endemic disease. But when by reason of the Napoleonic wars the armies came so re- peatedly in contact with each other and with the civil population, the disease became more widely disseminated and occurred in epidemics. In some coun- tries it became frightfully prevalent. In the English army, during the year 1818, there were more than 5,000 on the invalid list, who had been rendered blind as a consequence of trachoma. In the Prussian army, from 1813 to 1817, 30,000 to 30,000 men were attacked with it; in the Russian army, from 1816 to 1839, 76,811 men were subjects of the disease. In Belgium, in 1840, one out of every five soldiers was affected with trachoma. The French army, which was supposed to form the starting-point of the disease, was just the one that, relatively speaking, was least attacked. The armies disseminated trachoma among the civil population through the discharge of soldiers affected with eye diseases, through the quartering of troops, etc. When they had so many trachomatous soldiers in the Belgian army that they did not know what to do, the Government applied to Jilngken, who was at that time a celebrated oph- thalmologist in Berlin. He recommended them to dismiss the trachomatous 78 DISEASES OF THE EYE. soldiers to their homes. By means of this fatal measure trachoma soon became diffused in Belgium to an extent which has been observed in no other European state. Among the eiml population trachoma finds a favorable soil for its dissemina- tion in places where many men dwell together, hence among the poorer classes, but particularly in large public asylums. If trachoma has made its way into such an establishment, and no measures are taken against its spreading, soon a great number or even all the inmates will be attacked by it. In a pauper school at Holborn, the whole five hundred children suffered from trachoma (Bader). Hairion, in 1840, found in an orphan asylum at Mecheln sixty-four out of sixty-six orphan girls affected with trachoma; in Mons, seventy-one out of seventy-four orphan girls were suffering from the disease. In the workhouse at Dublin, no less than 134,838 persons were attacked by trachoma from 1849 to 1854. On board ships, where the crew live so closelj' crowded together, trachoma can spread very quickly. Mackenzie tells the story of the epidemic which raged upon the French slave ship Rodeur in the year 1819. The disease broke out during the voyage, and first among the negroes who, t^ the number of 160, were crowded together in the hold. When they took the unfortunate people up on deck, because the fresh air seemed to have a favorable influence on the ophthalmia, many threw themselves overboard, so that they had to desist from doing this. Soon one of the sailors also was attacked, and three days later the captain and almost the whole crew were taken, down with the disease, so that it was only with the greatest difficulty that the ship could be brought to its destination. According to the descriptions of that time, trachoma then ran a very acute course, and was attended with profuse secretion, circumstances which explain the rapidity with which the disease spread. Now that epidemics have ceased, this acute form has become rare. At present trachoma exists in many countries as an endemic disease, but mostly occurs under that chronic form under which, with scarcely any exceptions, we now see it. At the same time, its prevalence has diminished. In 1 888 the Prussian army had but ten trachoma patients for every 1,000 soldiers. In Austria, in whose eastern provinces trachoma is still very prevalent, 8 out of every 1,000 were affected with trachoma annually dur- ing the years 1881 to 1890. In the Orient there is a very different state of affairs. Thus in Egypt, even at the present time, it is scarcely possible to find a native who has a normal conjunctiva, and innumerable people there are blind. I'o be sure, the disease which plays such havoc and is known there as Egyptian ophthalmia comprises not only trachoma, but also acute blennorrhoea, which during the hot season does enormous injury. The different forms under which trachoma shows itself nowadays are re- garded by some as distinct diseases, and are denoted by different names, so that quite a good deal of confusion has gradually arisen in their nomenclature. In order to discover the relation existing between these forms, we must study first of all the anatomical alterations which characterize them. The papillary growths wliich impart to the conjunctiva its velvety or rasp- berrylike appearance are caused by an increase in size of the surface of the hypertrophic conjunctiva. The latter is thrown into folds, between which cor- respondingly deep clefts are formed; then on cross-section the folds appear under the form of papillae (Pig. 35, P and P,)- The connective tissue forming the papillae is stuffed full of round cells ; the surface of the papillce is covered DISEASES OF THE CONJUNCTIVA. 79 ■with a very much thickened epithelium (e, e), which, of course, is continued on into the depressions {t, t) that exist between the papilla. These depressions hence have in microscopical cross-section the appearance of a narrow canal coated with epithelium, and were accordingly regarded at one time as tubular glands; and hence the formation of new glands was alleged to occur in tracho- ma. That this in fact does sometimes occur can not be absolutely denied, for, even though the depressions between the papillae are not glands, yet tubes Fig. 25.— Cross-section through the TEACHOMiTon? Conjunctiva op the Upper Lid. Magnified 24 x I. Both small papillae, P. P, P, and large ones, P,. P,, are found. The former stand side by side like the pickets n( a palisade : the depressions, t, t. t, lying between them and coateii with epithelium, look like the tubules of glands. The large papillee contain trachoma granulps, T, Ti, which are not sharply limited and do not possess a capsule. The f pithelium of the conjunctiva is in many places, e. e, thickened. The mucous coat is in a condition of cellular infiltration, o, which is especially marked in the vicinity of the blood-vessels, g, g. coated with epithelium grow out from them and extend into the tissue of the conjunctiva, and these tubes are then in no respect distinguishable from true glands. Papillary hypertrophy of the conjunctiva, however, is by no means a char- acteristic feature of trachoma, in the sense of being limited to it alone. In a less marked degree it is found in connection with every long-continiicd irrita- tion of the conjunctiva ; as in chronic catarrh, in conjunctivitis eczematosa that has lasted a long time, in ectropion upon the portion of the conjunctiva that is exposed to the air, etc. Papillae, that are large but compressed and flat are the di-tinguishing mark of vernal catarrh (% 19). Still more intense degrees of papillary growth are observed after acute blennorrhoBa whenever the so-called chronic blennorrhoea develops from it. For this reason many authors call all cases of papillary trachoma chronic blennorrhoea, even though they have not been preceded by acute blennorrhoea. Others call the papillary form ophthal- mia purulenta chronica, others conjunctivitis granulosa or gra-.ii lations, because the papillae of the conjunctiva have a resemblance to the granulations of a wound. This resemblance, however, is a purely external one, fince the hyper- trophied conjunctiva does not have a raw surface, but is covered with epithe- lium; besides, by such a designation, a confusion would necessarily be produced with the granular form of trachoma. The granular form is characterized by the presence of trachomatous granu- lations. These, in microscopic cross-section, appear as a rounded aggregation of lymph corpuscles, forming, as it were, a little lymphatic gland or a lymphatic follicle, analogous to those which compose Peyer's patches. The trachomatous 80 DISEASES OF THE EYE. granulation either passes without any sharp line of demarcation into the sur- rounding tissue, which is also very rich in cells (Fig. 35, T and T^), or it has, especially in the case of the older granulations, a sort of incomplete capsule of connective tissue (Fig. 36, h). The subsequent fate of the trachoma granulations varies: some are gradu- ally transformed into tough connective tissue ; others undergo softening in 9 Fro. 36.— Trachomatous Granulation prom the Fou) of Transition. Magnified 24 x 1. The trachomatous granulation, T, pushes up the conjunctiva in the form of an elevation, and is inclosed by a layer of thickened connective tissue, the capsule, k. The conjunctiva is in- filtrated with cells, both in its upper layers, a, and along the vessels, g ; the epithelium, e, shows, above the place marked a, bright spots which correspond to the goblet cells ; at d It lines one of Henle's glands. their interior, and then by the breaking down of their investing epithelium are evacuated externally. In this case the loss of substance that remains is closed in by cicatrization (Raehlmann). The granular form is called trachoma verum, trachoma Arlti, and trachoma folliculare (Horner). Many, in view of the trachomatous granulations (gran- ules) present, give this form the name of granulations, while, as has been said above, others, on the contrary, use just this expression for the papillary form ; hence the confusion that exists. The mixed form (trachoma mixtum, according to Stellwag), which clinical observation has already shown to be the most frequent, is proved by micro- scopical examination to be almost the only one that occurs. That is, even in those cases in which papillae alone appear to the naked eye to be present, trachomatous granulations are found in cross-sections examined under the micro- scope, either lying within the papillae themselves or imbedded in the deeper portions of the mucous membrane. In the former case the papillae have a par- ticularly broad or even knob-shaped appearance (Fig. 25, Pi). In the second case the trachomatous granulations are concealed by the papillary bodies, be- neath which they lie ; then we often see them coming into view afterward, when the papillary growths have disappeared, as the result of a prolonged course of treatment. The gelatinous trachoma of Stellwag represents a later stage of mixed tracho- ma, in which a more uniform lymphoid infiltration exists in conjunction with superficial cicatricial changes. We have in that case a conjunctiva which is thickened, smooth on the surface, yellowish, and of gelatinous translucency. The transformation of the conjunctiva into cicatricial tissue proceeds as fol- lows : A part of the numerous cells which are contained in the conjunctiva, and which are either uniformly scattered through it or occur in circumscribed ac- DISEASES OP THE CONJUNCTIVA. 81 cumulations (trachomatous granulations), disappears by resorption ; another part owing to rupture of the granulations empties externally ; and still another part gradually grows into spindle-shaped cells, and finally into connective- tissue fibers. This new-formed connective tissue shrinks, and to such a great extent that the conjunctiva contracts and becomes thinner and of tendinous character. We have here a process similar to that which occurs in cirrhosis of the liver — i. e., the shrinking of a new connective tissue which has developed out of an inflammatory infiltration. It would be a mistake to suppose that in the trachomatous conjunctiva there are raw spots which become covered with a cicatrix — a mistake into which we might be more apt to fall because of the term granulations. What we call granulations in trachoma have nothing at all in common with the granulations of wounds, except their external appearance. Pannus proves, upon histological examination, to be a layer of new-formed tissue, which, starting from the limbus, spreads over the cornea (Fig. 27, P). It is a soft tissue, extremely rich in cells, which greatly resembles the infiltrated trachomatous conjunctiva. This tissue abounds in vessels, and occurs in alter- nately thicker and thinner layers, for which reason the pannus looks uneven and nodulated. Pannus, when it begins, insinuates itself between Bowman's membrane (Pig. 37, B) and the epithelium (Fig. 27, U), the latter being thus lifted off from Bowman's membrane and made to cover the pannus. The pa- renchyma proper of the cornea is protected by the still intact Bowman's mem- brane and sufl:ers no essential change. Hence it is possible for the cornea to regain completely its normal structure and transparency after the resorption of Fig. 27.— Cross-section through the Margin of a Cornea affected with Pannds. Magnified 1S5 x 1. Beneath the epithelium, E. E, is the limbus, i, greatly thickened by cellular ii^ltration; from it the pannus, P. in which are perceived the cross-sections ot several vesse s, extends be- tween the epithelium and Bowman's membrane, B, over the cornea, c. .b, sclera. the pannus, since then the epithelium is once more directly applied to Bowman's membrane. But this is possible in recent and slight cases only of pannus; later. Bowman's membrane gets to be destroyed in places, and the pannus then pene- trates into the corneal tissue proper, the superficial layers of which consequently are also destroyed in spots. Then the complete restoration of the transparency of the cornea has become impossible. For some forms and stages of pannus special names are in use. A recent pannus, which has not yet become thick, is called pannus tenuis, and, if it is very vascular, pannus vasculosus. If the pannus has acquired a considerable thickness, it is then known as pannus crassus or pannus carnosus. Sometimes the pannus is so big that one might imagine that he was looking at exuberant 6 82 DISEASES OF THE BYE. granulations ("proud flesh") upon the affected region of the cornea. This is pannus sarcomatosus. This adjective is also applied to the proliferating conjunctiva, as, for example, in the expression ectropion sarcomatosum. It would be best to discard these antiquated expressions altogether, and especially the designation sarcomatosus, which can give rise to confusion with neoplasms — sarcomata. An old pannus, composed of connective tissue and poor in ves- sels, is a pannus siccus. A rare metamorphosis of pannus has been observed in whicli tliere develops from it a dense white or yellowish tissue containing very few vessels. This tissue resembles a dense scar, e. g., such as occurs after deep ulcers of the cornea, but, unlike the latter, replaces only the superficial layers of the cornea ; extending, for example, from the upper border to the center of the cornea, if the pannus itself had covered the upper half of the latter. Another change in old pannus consists in the development of small, intensely white spots, ^-ihich frequently form a group in the pupillary region of the cornea. The appearance of the spots, which lie close to the delicate blood-vessels of the pannus, re- minds one of lead incrustation. The spots are superficial in seat, and may be removed by scraping (§ 45). 'For pseudopterygium, see § 32. What are the causes of pannus in trachoma ? Some see in pannus a direct transfer of the inflammatory process from the conjunctiva of the region of transi- tion to the cornea. Against the occurrence of any such transfer per continuitatem, it has been urged, and with justice, thpt that portion of the conjunctiva which is interposed between the fold of transition and the rim of the cornea, namely, the conjunctiva bulbi, takes little or no part in the trachomatous process. Another explanation starts from the fact that pannus in trachoma as a rule begins in the upper half of the cornea, and under ordinary circumstances has covered this portion entirely, before the lower half has been attacked at all. This would indicate that the upper lid, by reason of the roughness of its conjunctival sur- face, causes mechanically an irritation of the upper half of the cornea, and thus gives rise to inflammation in it. It is not to be doubted that this factor does come into play in the production of pannus, but it can not be the only nor even the most important cause of pannus ; for we often find the greatest roughness of the palpebral conjunctiva without pannus, and conversely find pannus in cases in which the palpebral conjunctiva is almost perfectly smooth. At the present time we can merely say that anatomically pannus is analogous to trachoma of the palpebral conjunctiva; that it is a trachomatous affection of that part of the conjunctiva which covers the cornea— i. e., of the conjunctival layer of the cornea. That this part of the conjunctiva becomes diseased in trachoma as readily as the conjunctiva of the lids or of the fold of transition, should not excite our wonder; on the contrary, it is more difficult to understand why the remainder of the conjunctiva, the conjunctiva scleras, does not take a more active part in the trachomatous process. Perhaps the following explanation is the correct one. Fig. 27 shows that the infiltration of small cells is particularly marked in the limbus of the cornea {L), and gradually diminishes as it extends from the latter over the cornea itself. So also, where we make a macroscopical inspection, we find the limbus, at the spot where a pannus is on the point of developing, intensely reddened and so greatly swollen that sometimes it forms quite a thick outgrowth. Hence the impetus to the formation of a pannus seems to be given by the trachomatous affection of the limbus. Now, then, we DISEASES OP THE CONJUNCTIVA. 83 must propound the following questions: 1. Why is it that the limbus in par- ticular is affected so intensely in trachoma ? and, 2. Why does the inflamma- tion pass from the limbus to the cornea and not in the opposite direction — i. e., to the scleral conjunctiva ? The first question must iind its explanation in the fact that the limbus is by far the most vascular portion of the bulbar conjunc- tiva, and hence the part that is the most apt to be inflamed. That the inflam- mation spreads from the limbus in a centripetal direction— that is, upon the cornea, and not in a centrifugal direction upon the conjunctiva sclera;, agrees vfith what we have been able to observe in other affections of the limbus and of the adjacent portions of the cornea. We are acquainted with many diseases in which inflammatory infiltrations or vessels push their way inward from the limbus into the cornea. Probably this depends upon the centripetal direction of the circulation of the blood in the scleral conjunctiva. The arterial vessels run from the periphery toward the limbus, where they form a dense network of capil- lary loops. At this point, where the centripetal stream of blood finds its limits, a circulation of lymph begins, which is directed in the same sense and which enters the cornea; and it is in the same direction that the inflammatory prod- ucts advance, and that the blood-vessels which jut out from the marginal loops of the cornea tend to make their way. Finally, it still remains to be explained why pannus generally begins at the upper margin of the cornea or why, in other words, the limbus is first affected at this point. If an eye is infected with trachoma, the conjunctiva is not attacked by the infection in its whole extent alike, but the infective matter adheres first to some circumscribed por- tion of the conjunctiva — generally to the conjunctiva of the tarsus or of the fornix, which is particularly apt to be affected with trachoma. Now, there are two ways in which the affection can spread from the portion of conjunctiva that is first attacked to other parts, namely, by continuity, in which case it extends gradually over the neighboring parts; and, by contiguity, in which case through contact with the diseased conjunctiva tarsi there is an infection of those portions of the conjunctiva bulbi that lie opposite tlie former, and espe- cially of the limbus, which is especially predisposed to infection. Now, it is precisely at the upper margin of the cornea that the limbus is in contact with the conjunctiva of the upper lid, and that, too, not only at night, but also all day, while the eye is open, since normally, even when the eye is open, the upper- most part of the cornea is covered by the upper lid. Here, therefore, the con- stant contact that exists is most favorable to an infection of the limbus by the diseased conjunctiva of the lids. That the rough condition of the latter assists in the production of this infection is likely. Such a condition acts partly as a mechanical irritant, partly by giving an impetus to infection through the production of small multiple lesions of the conjunctival and corneal epi- thelium. The pfmis which almost always accompanies trachoma and which gives tra- chomatous patients their characteristic appearance is in many cases attributable to the fact that the lid droops because it is heavy. Ptosis, however, is ob- served even when the thickening of the conjunctiva is inconsiderable, or indeed not present at all, and sometimes patients come to a physician solely on account of the ptosis, without having experienced any other trouble from their trachoma. There must therefore be some other cause for the ptosis beside the thickening of the conjunctiva. I suspect that the unstriated elevator of the lid (musculus palpebraUs superior— see § 105 and Fig. 21, p), whose muscular fibers lie directly 84 DISEASES OP THE EYE. beneath the conjunctiva of the retrotarsal fold, participates in the inflammation of the latter, and consequently becomes paralyzed. What relation do the separate forms of trachoma bear to each other ? Is trachoma papillare (blennorrhoea chronica, etc.) a disease perfectly distinct from trachoma granulosum (trachoma verum, etc.), or are both merely different forms of the same process ? Anatomy shows that in the enormous majority of cases the changes that are characteristic of the two forms (papillary growths and trachomatous granulations) are found simultaneously, so that scarcely any un- mixed cases of either form are left. This speaks decidedly for the unitary theory of the disease. We arrive at the same result if we follow out the etiology of the disease. Cases are observed in which one individual affected with one of the two forms infects other persons, in some of whom thereupon the same form, in others the other form develops. Piringer, moreover, by his inoculations experimentally established the fact that the secretion from one and the same case produced the first form in one individual, the second form in another; indeed, in one and the same person there was once produced by inoculation with the same secretion one form in one eye, the other form in the other. We are therefore quite justified in regarding the two forms of granular and papillary trachoma as one and the same disease. It still remains to speak of the position of follicular conjunctimtis with re- gard to trachoma. The former is found chiefly in young people, while tracho- ma, on the contrary, is very seldom met witli in children. The two diseases are very similar, in that lymph follicles occur as characteristic formations in both. In follicular catarrh they are smaller, are more sharply limited, and pro- ject farther above the surface of the conjunctiva ; in trachoma they are larger, destitute of sharp outlines, and less prominent. Follicles proper are often oblong-oval (cylindrical) and placed side by side, in a row like a string of pearls, while trachomatous granulations are round and more rarely present any such arrangement in rows. But these characteristics are sometimes so obscured that even experts can not, in many cases, make the diagnosis with certainty, and the subsequent course of the disease alone affords the desired information. Even in the histological structure no thoroughgoing distinction can be found between follicles and trachomatous granulations. A further resemblance be- tween follicular catarrh and trachoma consists in the fact that they both chiefly occur among bodies of men who are confined in a small space. It is therefore easy to understand that these two diseases have repeatedly been confounded with each other ; and a number of authors, in fact, explain follicular catarrh as being a kind of trachoma distinguished by its mildness and freedom from danger. But to such a view the following objection must be raised : It is not yet certain whether follicular catarrh occurring among conBned bodies of men is propa- gated by infection, like trachoma, or is merely a result of the contamination of the air by dust, exhalations, etc. On the other liand, it is quite satisfactorily established that, uuder certain circumstances, follicular catarrh can arise with- out any infection whatever. This is the case after the prolonged instillation of atropine, which is followed in many persons by the development of a typical follicular catarrh with very numerous follicles. But trachoma can never arise without infection. A further and more important distinction between the two diseases is the course. Follicular catarrh is not associated, or is associated to only an inconsiderable degree, with papillary hypertrophy of the conjunctiva; it never leads to shrinking of the conjunctiva, to pannus, or to any of the other DISEASES OP THE CONJUNCTIVA. 85 sequelse; it is a disease perfectly devoid of danger, one which, even without any treatment, finally gets well and leaves no trace behind; so that on this account alone the differentiation of the two diseases is not only theoretically, but also practically, of great importance. The question with regard to the relations of the different forms of blennor- rhoea, trachoma, and follicular conjunctivitis to each other will first receive a definitive solution through the medium of bacteriology. At present only the micrococcus of acute blennorrhoea, the gonococcus, has been satisfactorily de- termined. In conjunctival diseases which, like trachoma and follicular catarrh, are associated with the formation of granulations several observers (Leber, Battler, Koch, Michel, and others) have also proved the existence of micro- organisms, some of which pretty closely resemble the gonococcus without being identical with it. So far, however, the observations of individual investigators are not sufficiently accordant for us to be able to formulate any definite conclu- sions. Probably we must regard the formation of granulations composed of adenoid tissue not as anything at all specific, but only as a particular form of re- action, which the conjunctiva of the eye, like other mucous membranes, exhibits toward many different sorts of irritants. Such a formation of granulations occurs in its most pronounced form in trachoma and in follicular catarrh. Furthermore, in the chronic stage which follows acute blennorrhoea granulations in the retro- tarsal folds are frequently found in conjunction with the papillary hypertrophy of the conjunctiva, and sometimes in such quantity that a true trachoma is thought to be present. Then there are cases of tuberculosis of the conjunctiva (see § 19) which begin with an abundant development of granulations, quite as in trachoma; of these Rhein has described some examples, and I myself have seen several. Again, Goldzieher and Sattler have seen cases in which there was an abundant formation of granulations in a conjunctival affection which they regarded as syphilitic. The former observer also described under the name of lymphoma conjuneti'ca; a disease in which gigantic lymph follicles are found in the conjunctiva, to- gether with lymphomata in the neck on the same side as the affected eye. In regard to the follicular catarrh produced hy atropine, it appears that the irritation is a chemical one, and hence the catarrh disappears when the atro- pine is replaced by another mydriatic. For getting rid of a thick pannus many employ peritomy. This is the opera- tion of dividing the conjunctival vessels running to the pannus, either by simply making an incision round the cornea through the conjunctiva, or by excising a narrow annular strip of the latter. In order to make an old pannus transparent, it was formerly the practice to deliberately make an inoculation of acute UennorrMa, because it had been found by experience that an eye with pannus which is accidentally attacked by acute blennorrhcea, instead of losing its cornea by suppuration, has its pannus niade actually more transparent. The procedure is, at the present time, re- placed by the treatment with jequirity, which accomplishes the same thing without exposing the eye of the other side, or the eyes of other persons, to the danger of blennorrhoeal infection. Jequirity (the seeds of the Abrus praecatorius) has for a long time been in use in Brazil, where trachoma is epidemic, as a popular remedy for this disease. To De Wecker is mainly due the credit of having subjected this remedy to scientific examination and of having introduced it into Europe. The action of 86 DISEASES OP THE BYE. jequirity does not depend upon the presence of micro-organisms in the infusion, as was originally believed, but upon an unorganized ferment which is excess- ively poisonous (Hippel, Neisser, Salomonsen, Venneman). IV. Conjunctivitis Diphtheeica. 16, Conjunctivitis diphtherica,* like acute blennorrhoea and tra- choma, is a purulent inflammation of the conjunctiva which spreads by contagion and the secretion of which is infectious. But the con- tagium is different from that of the other two diseases, being in this case the diphtheria bacillus of Loffler. The inflammation produced by this is always violent, and in the severe cases is among the most intense of any that are observed in the conjunctiva. The lids are much swollen and reddened, hot, and painful to the touch. In particularly severe cases the lids are actually of boardlike hardness, so that it is impos- sible to evert them, and scarcely possible even to open the palpebral fissure. The lymphatic glands in front of the ear or in the neck are swollen. The appearance of the conjunctiva is characteristic of the property that the diphtheria bacillus possesses of producing a profuse exudation, which has a great tendency to coagulate. This coagulation either affects the exudate that is poured out upon the surface of the con- junctiva, and which consequently clots to form membranes or it takes place within the tissue of the conjunctiva. Consequently we may dis- tinguish two forms of diphtheria of the conjunctiva. (a) The sitperjlcial or croupous form. This is characterized by the presence of a grayish-white membrane, which adheres pretty closely to the surface of the conjunctiva, but still can usually be removed from it with a forceps. When this is done we find the conjunctiva beneath to be greatly reddened and swollen and in some places bleeding, but we notice no great losses of substance in it. The membrane itself consists of a fibrous meshwork of clotted fibrin, in which pus corpuscles and a few epithelial cells from the conjunctiva are imbedded. The croupous membrane covers the tarsal conjunctiva ; more rarely, the retrotarsal fold and even the conjunctiva of the eyeball. In most cases after from one to two weeks the membrane gradually disappears. The eye now merely presents the condition of an intense simple catarrh, which gets well without leaving any permanent changes in the conjunctiva. In severe cases the disease is complicated with corneal ulcers, which, how- ever, but rarely lead to extensive destruction of the cornea. (b) The deep form (diphtheria of the conjunctiva in the narrower sense). This runs a much more serious course than does the superficial form, as in order for it to occur the exudate must coagulate while still within the tissues of the conjunctiva, so that the vessels are compressed by it, and the mucous membrane consequently is rendered rigid and * Prom Stipdtpa, a membrane. DISEASES OF THE CONJUNCTIVA. S7 bloodless and falls a prey to necrosis. Hence, on everting the lids we find beside the marked swelling and redness of the conjunctiva spots in which the conjunctiva is somewhat depressed, smooth, and of a grayish- yellow color, and often contains a few dirty-red speckled markings (ecchymoses). In the severest cases, either a very large portion of the conjunctiva, or even its entire surface, acquires this character and is uni- formly gray and hard, just as it is after being intensely cauterized, e. g., by the action of quicklime. The condition just described, which develops rapidly after a short period of incubation, is called the first stage of the disease, or stage of infiltration. It keeps up for from five to ten days, according to the ex- tent of the diphtheritic process upon the conjunctiva. Then the spots of diphtheritic infiltration begin gradually to disappear. Where the infiltration is not so very dense, resorption of the exudate occurs, but in those spots from which the circulation has been altogether cut oif by the infiltration and the tissue has consequently mortified the necrotic portions slough away. Thus are produced in the conjunctiva losses of substance, which soon become covered with granulations such as cover a raw surface. Meanwhile the secretion has become more abundant and more purulent, for which reason this second stage is characterized as the stage of Hennoi-rlima. The third stage is that of cicatrization., in which the granulating surfaces, that are produced by the sloughing oS of the gangrenous portions of the conjunctiva, grad- ually grow smaller and are covered over with a new epithelial lining. Since the latter change is effected by the drawing in of the neighbor- ing conjunctiva, the conjunctival sac as a whole is contracted ; fre- quently, too, in single spots adhesions are produced between the con- junctiva of the lid and that of the eyeball (symblepharon). The more extended the diphtheritic process the more striking is the subsequent cicatricial contraction of the conjunctiva. As a result of it trichiasis, cicatricial entropion, or even xerophthalmus may subsequently develop. The deep form of diphtheria is more severe than the croupous, not only in regard to its effect upon the conjunctiva, but also in other re- spects. Hence the cornea is much more frequently and much more seriously affected. The greater the extension of the diphtheritic pro- cess upon the conjunctiva the more certain is corneal suppuration to occur. If the entire area of the conjunctiva is infiltrated and rigid the cornea is always irretrievably lost. The general condition of the little patients is very much disturbed. They have high fever and are greatly prostrated. Weakly children not infrequently succumb to the severity of the general disease. The prog- nosis, therefore, is very serious, not only as regards the eye, but also with respect to life itself. Etiology.— That the two forms just described, which differ so much in their appearance and course, are, nevertheless, the same disease. 88 DISEASES OF THE EYE. namely diphtheria, is proved from the fact that Lofder's bacilli are found in the conjunctival secretion in both. Often, too, the patients present other important and undoubted diphtherial affections. Small-sized diphtherial patches are frequently found at the edges or angles of the lids, the nostrils, or the angles of the mouth ; sometimes there is also a fully developed nasal or pharyngea,! diphtheria. Diphtheria of the conjunctiva is mainly observed in those countries where diphtheria of all sorts is a frequent occurrence,* and occurs es- pecially at times when an epidemic of pharyngeal diphtheria is prevail- ing. It can often be proved that children affected with diphtheria of the conjunctiva had previously been thrown with others, who soon afterward developed pharyngeal diphtheria; and such children may themselves in their turn spread the disease to others still. The predispo- sition to diphtheria diminishes with the age. Consequently, diphtheria of the conjunctiva usually attacks children, and most frequently those between the second and eighth year of life. Adults are only exception- ally attacked, and then by one of the lighter forms. Treatment. — In the severe cases of diphtheria of the conjunctiva the injection of antitoxin is indicated as soon as the diphtherial charac- ter of the disease is made out. In the lighter cases we may content ourselves with employing local treatment alone. In the first stage of the disease this is chiefly limited to careful cleansing of the eye, for which purpose the best thing for us to employ is a weak antiseptic liquid (solution of corrosive sublimate, salicylic acid, or potassium per- manganate). Cold compresses, which would seem to be indicated by the great swelling and redness of the lids, must be applied only when the conjunctival circulation is not too seriously embarrassed by the diphtherial infiltration. Otherwise, it is better to employ warm com- presses which by dilating the blood-vessels increase the circulation. As regards the conjunctiva itself Fieuzal has recommended painting it with lemon juice ; and painting it with strong sublimate solution (1 to 1,000) either directly or after the removal of the membrane, if present, is highly spoken of, Except for this purpose there is no object in removing the membranes in the croupous variety, since these at once reform. When, after separation of the membranes or the slough, the conjunctiva has become strongly congested, soft, and succulent, and the secretion begins to be abundant, we may commence the application of a nitrate-of-silver solution, by means of which we bring the swollen con- junctiva more rapidly back to its normal state. In so doing we must at first proceed with great caution, use a pretty weak solution (one per cent) and discontinue the application at once if membranes or deep in- filtrations once more develop. [* In America severe cases of conjunctival diphtheria are ol rare occur- roncc. — D.] DISEASES OP THE CONJUNCTIVA. 89 We keep on making the applications to the conjunctiva as lon^ as the latter is red and swollen and discharges a copious secretion. If in the deep form after the subsidence of the disease partial necrosis and sloughing of the conjunctiva have set in, we try during the subsequent period of cicatrization to oppose, as far as possible, the formation of ad- hesions between the lids and the eyeball (doing this by frequently draw- ing the lid away from the eyeball or by laying a pledget soaked in oil between the two), for adhesions once formed can be removed only by an operation. Complications affecting the cornea are to be treated ac- cording to the rules that will be given further on for purulent inflam- mation of the cornea in general. All operative procedures, whether upon the cornea or upon the lids, should be avoided in the first stage, as the wounds thus produced gen- erally become diphtherial too. In consideration of the very infectious character of diphtheria, our special aim must be prophylaxis. While acute blennorrhcea and tracho- ma exert an infectious action only through a transfer of the secretion, infection in diphtheria can, in all probability, occur simply by means of the air, without any direct transfer. Accordingly, we remove from the vicinity of the patient all persons who are not indispensably neces- sary for purposes of nursing ; but, most of all, we insist upon the removal of children, who are particularly susceptible to infection. If diphtheria has attacked only one of the patient's eyes, the other must be protected against infection by a carefully applied occluding bandage, just as in acute blennorrhcea. The persons who have charge of the patient must be particularly enjoined to cleanse the hands carefully after touching the diseased eye, to destroy at once the materials employed in cleansing, etc. We owe the first exact description of conjunctival diphtheria to Von Graefe, who, in Berlin, had an opportunity of seeing many cases of this disease. His description relates to the deep variety, of which he distinguishes two groups of cases. In the first group— that of diphtheria en plaques — constituted by the lighter cases, the diphtherial spots in the conjunctiva are found under the form of large or small islands, which occur especially on the conjunctiva of the lids and between which lie areas of tissue that is not so much diseased. In the severer cases, on the other hand, the diphtherial foci rapidly coalesce, so that the entire conjunctiva becomes rigid and bloodless (confluent diph- theria). After Loffler had discovered in the membranes of pharyngeal diphtheria the bacillus that bears his name, it was soon after shown to be present in diphtheria of the conjunctiva also (Babes, Kolisko and Paltauf, and others). On the other hand, no one supposed that the cases in which a membrane forms upon the conjunctiva must also be regarded as diphtheria until the presence of the Lofller bacillus was demonstrated in them also (C. Frankel, Uhthoff, Elsch- nig, Escherich, Sourdille, Schirmer, and others). The same thing occurred in this case as in that of pharyngeal diphtheria and laryngeal croup, whose etio- 90 DISEASES OP THE EYE. logical identity has only very recently been recognized. Many assume that membranous inflammation of a mucous membrane implies a feebler action of the diphtheria bacilli than does diphtheritic inflammation proper, the comparatively slight effect of the bacilli in the former case being due either to their having lost their virulence or to the patient's being more refractory to the influence. But apart from this, the severity of the inflammation is influenced by the fact that beside the Loffler bacillus there occur on the inflamed conjunctiva other germs, such as the staphylococcus and streptococcus. In fact, the streptococ- cus by itself is competent to produce a disease of the clinical aspect of con- junctival diphtheria; and in my clinic actually the severest cases were those in which the streptococcus alone was present, the slighter or croupous cases being associated with the Lofiler bacilli. Croupous Membranes on the Conjunctiva.— Croup and diphtheria are primarily anatomical terms denoting definite forms of inflammation. Croupous inflammation is characterized by the deposition of an exudate upon the surface of a tissue, where, by coagulation, it hardens into a membrane. The essence of the diphtheritic inflammation, on the contrary, consists in the exudation of a great mass of material within the tissue itself, together with consecutive necro- sis of the latter. Diphtheritic inflammation may be regarded as a croupous inflammation carried to a higher point, in so far as the same injurious cause may, when acting to a slight extent, produce a croupous, when acting to a greater extent, a diphtheritic inflammation of the mucous membrane. Sourdille has demonstrated experimentally that by painting the conjunctiva with am- monia one can at will produce either the croupous or the diphtheritic form of inflammation, according to the intensity, greater or less, with which the agent is applied. We meet with the same experience in our medical practice, when, by maliing too strong or too frequent applications of the silver solution to an inflamed conjunctiva, we produce a croupous coating upon it, and then, in spite of this result, keep on witli the application. In this case a diphtheritic inflam- mation with circumscribed necrosis of the tissue will ensue. Chemical irritants of an organic nature may bring about the same result. Thus the repeated appli- cation of the jequirity infusion produces first a croupous, afterward a diphthe- ritic inflammation. And, furthermore, the same thing holds good for many of those infliimmations of the conjunctiva that are caused by micro-organisms. Thus in an acute blennorrhoea, when the inflammation attains a high degree of severity, either a croupous coating or a diphtheritic infiltration of isolated por- tions of the conjunctiva may be observed, and such cases are often regarded as genuine diphtheria. Accordingly, the same clinical picture— e. g., that of a diphtheritic con- junctivitis—may be produced by the most various kinds of pathogenic agents, both of a chemical and a parasitic nature ; and, on the other hand, the same pathogenic agent — e. g., the Loffler bacillus— may give rise to a variety of clin- ical pictures — i. e., to both croupous and diphtheritic inflammation. It is not ten- able, therefore, as has hitherto been done, to employ the expressions croup and diphtheria of the conjunctiva both to characterize certain anatomical changes, and also to denote definite types of disease, each of single etiology. With re- gard to the expression diphtheritis, I have adhered to Roser's proposition, using the word diphtheritis as an anatomical term for that variety of inflammation in which the exudate undergoes coagulation within the tissue itself. On the other hand, diphtheria and diphtherial are used in an etiological sense to denote DISEASES OP THE CONJUNCTIVA. 91 those affections which, whatever appearance they may present, are caused by the Loffler bacillus. The expression croupous conjunctivitis should be used simply as an anatomical term. Formerly most of the spontaneously developing conjunctivitides that were associated with the formation of a membrane were comprehended under the terms conjunctivitis cruposa or menibranacea, and thought to constitute a single independent disease. But recent bacteriological investigations have shown that the most various pathogenic agents may give rise to the formation of a mem- brane upon the conjunctiva. As far as is at present known, a croupous con- junctivitis may originate from the following causes: (a) Spontaneously developing croupous conjunctivitis. This usually runs an cuMte course, and is the kind that was formerly described under the name of conjunctivitis cruposa as a distinct disease. We have seen above that a part of these cases, being caused by the Loffler bacillus, are to be attributed to diph- theria. This knowledge is practically important, because we now know that even these apparently light cases of conjunctivitis may by transfer to others produce severe diphtheria of the conjunctiva or of the pharynx, and that we must consequently apply to them all customary precautionary measures. Croupous inflammations, in part of a serious character, are caused by the streptococcus (Terson, Bourgeois and Gaube, Debierre), and less severe kinds by the pneumococcus (Moras, Parinaud). Among the cases that run a light course belong also those of acute catarrh, that are produced by the bacillus of Weeks, and are associated with the formation of membrane (Morax) ; and that the acute blennorrhoea caused by the gonococcus not infrequently shows mem- brane foiTnation has already been stated above. To the cases of membrane formation upon the conjunctiva that pursue a more chronic course belong the very rare instances of herpes iris of the con- junctiva. These latter can readily be diagnosticated, provided the characteris- tic exanthem of herpes iris (a central reddened or pigmented area of skin sur- rounded by a wall of vesicles) is also to be found upon the skin. This, however, is not always present. Sometimes, too, a formation of membrane like that upon the conjunctiva occurs upon the mucous membrane of the mouth. In some cases the disease recurs frequently. In one case, which probably belongs here, Gerke and Kain isolated a coccus which, inoculated upon a rabbit's con- junctiva, produced a formation of membranes there. Furthermore, there have been described cases of peculiarly chronic forma- tion of membrane upon the conjunctiva— cases lasting for months, or even years— the nature of which is still doubtful (Arlt, Hulme, Morton, and others). (h) By the application to it of external irritants of a chemical nature the con- junctiva may be thrown into a state of inflammation with the foi mation of a membrane. As already mentioned, such irritant substances include bodies both inorganic and organic, like ammonia, nitrate-of-silver solution, and jequirity infusion. (c) Losses ofsuUtance in the conjunctiva (and the same thing is seen in other mucous membranes) verv soon become covered with a membrane of coagulated fibrin, under which the healing of the wound proceeds. This process is observed after operations (e.g., tenotomy), injuries, and also spontaneously developing wounds— as, for example, those occurring after rupture of pemphigus vesicles (see § 18). 92 DISEASES OF THE EYE. V. Conjunctivitis Eczematosa.* 17. Symptoms.— In its simplest, typical form, conjunctivitis ec- zematosa presents the following picture : A little red eminence, of about the size of a millet seed, develops at some point i^pon the limbus of the conjunctiva. This is the efflorescence (Fig. 28). In the be- ginning it is conical, its apex being covered by the epithelium of the conjunctiva. In a short time the epithelium at the summit of the efflorescence separates, and the tissue that lay beneath it breaks down, so that the apex of the cone, so to speak, melts away ; and the cone S Fig. 28. — Eczematous Efflorescence in the Limbus. Magnified 62 x 1. The sclera, S, is distinguished by its more dehcate fibrillation and its blood vessels from the more homogeneous, nonvascular cornea, H. The nodule is situated at a point corresponding to the boundary between the two membranes, but more over the sclera than over the cornea. It consists of densely packed round cells, between which the blood-vessels are recognizable under the form of hghter-colored strise. In the vicinitj^ of the nodule the vessels of the con- junctiva (c) and episclera (e) are bordered by extravasated leucocytes. The epithelium (.E) of the conjunctiva is bulged forward by the nodule, and at the apex of the latter is thinned, and, owing to the penetration of the round cells into the epithelial layer itself, has lost the sharp border ordinarily existing between it and the connective tissue. itself bears on its top a minute gray ulcer, which thus lies above the level of the neighboring, heavy conjunctiva. By a continuation of the breaking-down process the cone at length disappears entirely, the ulcer sinks to the level of the conjunctiva, and speedily becomes clean and then covered with epithelium. Thus the ulcer heals, without a visible mark being left upon the conjunctiva. As the efflorescence springs up, the adjacent part of the conjunc- tiva becomes hyperEemic, the injected vessels being directed from all sides toward the little nodule. Hence, the reddened portion of the conjunctiva shows the form of a triangular sector, the apex of which lies in the limbus and corresponds to the nodule. The remainder of the conjunctiva is perfectly free from congestion. * Synonyms : Conjunctivitis lymphatica (scrofulosa, phlyotffinulosa, pustulosa, exanthematica), herpes conjunotivBB (Stellwag). DISEASES OP THE CONJUNCTIVA. 93 The simplest type of conjunctivitis lymphatica, therefore, consists in the formation of a sharply circumscribed, nodular exudate, to which there corresponds an injected district of the conjunctiva. Conjunc- tivitis lymphatica is hence & focal affection of the conjunctiva of the eyeball, and is thus distinguished from all the varieties of conjunctival inflammation hitherto described which are diffused inflammations, in that they extend in a uniform fashion over large sections of the con- junctiva. The clinical pictures which conjunctivitis eczematosa actually ex- hibits present modifications of the type above described, which differ most widely from each other. These modifications concern — (a) The nvmber of the efflorescences. It is rare that we find but one of these ; generally there are several, and not infrequently a good many, present at the same time. The fewer they are the larger they generally grow ; in rare cases they almost attain the size of a lentil. AYhen there are many nodules present they are small ; often we find the entire limbus, or even the cornea itself, covered with very minute emi- nences, so that the surface of the eyeball looks as if fine sand had been strewn over it. Such very small nodules commoqly disappear in a few days by resorption, without any preliminary disintegration. When multiple efflorescences are present, the injected portions of the bulbar conjunctiva belonging to the separate nodules become confluent, and the conjunctiva then appears reddened all over, so that the focal char- acter of the disease is obscured, and declares itself only by the presence of separate nodular exudates. So, too, when the inflammation is great, the pal- pebral conjunctiva also par- ticipates in the injection, so that, in that case, conjunctivi- tis eczematosa is no longer an affection limited to the bulbar conjunctiva. (b) The site of the efflor- escences may be not only in the limbus itself, but also ex- terior to the latter, in the an- terior segment of the bulbar conjunctiva, and likewise in- terior to the limbus, in the cornea itself. In the latter are situated small gray nodules, which consist of an accumulation of round cells superficially disposed between Bowman's membrane (Fig. 39, B) and the epithelium (Fig. 29, U), which is bulged forward by them. By the breaking down of the nodule there is produced in the cornea a loss of Fis. 39.— Efflorescence on the Cobnea in Con- junctivitis Eczematosa. (After Ivvanoff.) The nodule, which consists of cells, lies between Bowman's membrane, B. and the epithelium, E, which latter is thus raised so as to form a prom- inence. In the epithelium we distinguish the lowermost layer of cylindrical cells, ti, the mid- dle layer of polygonal cells, m, and the upper- most layer of fiat cells, o ; scattered between the epithelial cells lie a few round cells, r. A nerve, n, is seen extending through the parenchyma of the cornea, C. and among the corneal corpuscles, K, up to the nodule. 94 DISEASES OP THE EYE. substance, which is quite shallow, affects merely the epithelium, and heals without leaving a permanent opacity. Often, however, the affec- tion assumes a more serious form, from the fact that the exudations have a tendency to spread farther in the cornea, extending either into the depth of the latter or along its surface. If the infiltration extends through -Bowman's membrane into the parenchyma proper of the cor- nea, an ulcer is produced, when it breaks down, which penetrates more deeply and can even perforate the ftornea. In that case, after the ulcer heals, a permanent opacity remains. (c) The corneal ulcers which result from the efflorescences may assume a serpiginous character — that is, they may spread by a sort of creeping process along the surface of the cornea. " In this way is pro- duced the vascular fasciculus (Fischer), which is also called keratitis fascicularis. This affection begins by the development of a small ulcer out of an efflorescence at the rim of the cornea. After some days this ulcer becomes clean in its peripheral half — that is, in the part turned toward the corneal rim. At the same time, in accordance with the ordinary behavior of regressive corneal ulcers, blood-vessels develop, which run from the limbus to that edge of the ulcer that is healing, and which serve to keep up the process of cicatrization. But in the meantime, that margin of the ulcer that is toward the center has re- mained infiltrated and gray. Inasmuch as at this place the infiltration and the subsequent purulent disintegration keep on extending, the ulcer constantly advances toward the center of the cornea, while on its j)e- ripheral side it heals equally fast, and draws the blood-vessels after it. The vascular fasciculus accordingly appears as a narrow red band formed of blood-vessels (hence the name), and extending from the corneal margin some distance into the cornea. At its apex it bears a small gray crescent, the infiltrated, advancing margin of the ulcer. The arrest and recession of the process first occur when the ulcer is completely healed. Until this has taken place the vascular fasciculus can advance far into the cornea, to its center or even beyond it. The small ulcer, however, always remains superficial, and a perforation of the cornea due to it has never been observed. When the vascular fasciculus has at length come to a standstill, the vessels gradually disappear from it, and there only remains a superficial opacity of the cornea which corresponds in shape to the long-drawn-out form of the vascular fasciculus. This opacity never clears up again completely, and hence, when found at any time during the whole subsequent life of the patient, enables us to diagnosticate the previous existence of a vascular fasciculus. (d) The severest cases of conjunctivitis eczematosa are those in which the exudation, starting from in front, makes its appearance in the deep layers of the cornea as a diffused deep-lying infiltration. We then find the cornea occupied to a considerable extent by an opacity of a uniform gray or yellowish color, becoming fainter toward the edges. DISEASES OP THE CONJUNCTIVA. . 95 This opacity is situated in the deep layers of the cornea ; and the sur- face of the cornea over it is dotted with minute spots. In the bad cases the infiltrate, originally gray, becomes more and more yellow, and finally breaks down into pus, so that an extensive loss of substance is produced in the cornea. In the benign cases, on the contrary, the in- filtrate gradually disappears again by resorption, and the cornea regains its transparency either wholly or in part. It is astonishing to what an extent even extensive infiltrates can undergo resolution. (e) Instead of appearing as separate circumscribed foci, the exudate may occur under the form of a continuous new formation of tissue upon the surface of the cornea — that is, under the form of pminiis. This is called pannus eczematosus, to distinguish it from trachomatous pannus. It does not, like the latter, show a predilection for the upper part of the cornea, but develops from any spot whatever upon the cor- neal margin. It is ordinarily thin and not very vascular, and is quite disposed to undergo complete resolution. Conjunctivitis eczematosa is generally accompanied by abundant lachrymation. Mucous or muco-purulent secretion, on the contrary, such as occurs in catarrh, is not present as a rule ; hence the lids do not ordinarily stick together in the mornings. The only exception to this is formed by those old cases in which the inflammatory process has passed over to the palpebral conjunctiva, and has thrown it into a state of concomitant catarrhal inflammation. The subjective symptoms consist of photophobia and spasm of the lids (blepharospasm). Slight in some cases, in others they reach an extraordinary pitch ; children creep into a dark corner of the room, bury their faces in their hands, and struggle so violently against any at- tempt at opening their eyes that the examination on the part of the physician is conducted under great difficulties. The intensity of these symptoms bears no deflnite relation to the severity of the disease; in fact, it is precisely in that form of corneal affection which spreads more extensively and penetrates more deeply that the evidences of irritation are often pretty slight. The annoyance suffered, contrary to what takes place in conjunctival catarrh, is, generally speaking, greater in the morning than in the afternoon and evening. Course and Prognosis.— A single typical efBorescence upon the limbus passes through all its phases up to complete subsidence in eight to fourteen days. If several efflorescences are present, the process of cure requires a proportionately longer time. ISTevertheless, the disease would not last so very long if it limited itself to a single attack. This, however, is but rarely the case. Usually, after a period of quiescence, or even before the first attack of inflammation has quite run its Course, the eye becomes red again, and new nodules shoot up in or near the limbus. Thus the disease may, with longer or shorter intermissions, last on for months or years. Its beginning occurs in childhood ; the 96 DISEASES OP THE EYE. separate attacks, however, are often protracted until the time of puberty, or sometimes even later ; the affection being situated, now in one eye, now in the other, then in both at the same time. Finally, the attacks become less and less frequent, and at length cease alto- gether. The constant wetting of the lids by the tears frequently leads to blepharitis, to eczema of the skin covering the lids, and, as a conse- quence, to ectropion of the lower lid. Excoriations are frequently pres- ent at the external angles of the lids, and blepharophimosis often develops later on. The prognosis of conjunctivitis eczematosa is favorable, in so far as the eye is but rarely rendered entirely blind by it. Superiicial efflores- cences disappear without leaving a trace behind ; ulcers which penetrate into the parenchyma proper of the cornea leave permanent opacities, which, however, are in most cases thin and superficial (macule of the cornea). In persons who have gone through with many recurrences of conjunctivitis eczematosa the cornese often bear quite a number of such maculae as signs of past attacks. Thus the sight is impaired, the patients being often incapable of doing fine work. In addition to this, chil- dren, in consequence of the frequently repeated inflammations of the eyes, fall behind in their physical and mental development. So, even if conjunctivitis eczematosa only in exceptional cases leads to blindness, it nevertheless does so much harm to those who are attacked by it, that we ought to strive to combat it with every means in our power. 18. Etiology. — Conjunctivitis eczematosa is one of the most fre- quent of eye disease's, and it has its origin in the scrofulous diathesis. Like the latter, it is a disease of childhood and youth. In very young children — those under the age of one year — it occurs but seldom, and it generally ceases at the time of puberty. Adults are attacked by it only ill case they have carried the disease along with them from their childhood. The enormous majority of children affected with conjunc- tivitis eczematosa belong to the poorer classes. Such children receive insufBcient and unsuitable nourishment, live in damp, poorly ventilated dwellings, and are kept constantly dirty. Other children aSected are those who, though once healthy, have become run down as a result of other diseases (scarlet fever, measles, typhoid fever, whooping cough, etc.). Such children as these look either pale and thin or bloated and flabby, like a sponge. The glands at the lower jaw, in the neck, and in front of the ear, are swollen. Partly as a result of the suppuration of these glands, and partly as a result of the breaking down of the scrofulous infiltrations in the skin, ulcers and fistulous passages are produced, which require months and years for their cure, and leave characteristic and disfiguring scars behind. Patches of moist eczema occur at various spots upon the body, most frequently upon the face • and the constant coryza from which many of these children suffer is DISEASES OF THE CONJUNCTIVA. 97 to be attributed to an eczematous affection of the nasal mucous mem- brane. In the lids we find blepharitis. The nose and the i;pper lip are rendered thick by frequently recurring attacks of inflammation. More profound affections that occur are caries of bones (caries of the petrous bones appearing under the form of an otorrhoea being frequent), tuberculosis, and, in girls, delayed and irregular menstruation. Some one of the above-mentioned symptoms of scrofula, and often several of them at once, accompany most cases of conjunctivitis ec- zematosa. Sometimes, though rarely in comparison with the other cases, the disease is observed in an individual who otherwise is quite healthy, just in the same way that other indications of scrofula also occur at times as altogether isolated phenomena. Therapy. — In the lighter cases, the local treatment consists in the application of irritants, of which calomel and the yellow-precipitate ointment (Pagenstecher's ointment) are most in use. The calomel in a finely powdered state is sprinkled in a thin layer upon the conjunc- tiva of the lower lid by means of a camel's-hair brush ; the precipitate ointment (0.05 to 0.15 of yellow precipitate to 5 of fat), on the other hand, is introduced into the conjunctival sac by means of a glass rod or a brush, and is then rubbed about with the lids, so as to be dis- tributed over the whole conjunctiva. Both remedies are irritant in their action ; the precipitate ointment more so than the calomel. Hence, in the beginning of the disease, where the eyes are in a marked state of irritation, it is best to employ calomel; and subsequently, when the inflammatory symptoms are diminishing, to replace this by the yellow ointment. The remedies mentioned are to be applied only once a day. Both find a contrain- dication in the presence of recent infiltrates or progressive ulcers in the cornea. In such cases, before having recourse to irritant remedies, we must wait, meanwhile employing atropine, until the process of in- filtration has subsided or the ulcer has become clean. Pannus and vascular fasciculi do not contraindicate calomel or the yellow ointment. If under their use the vascular fasciculi can not be brought to a stand- still, we cauterize the advancing edge of the ulcer with the point of a delicate cautery iron (or with a galvano-cantery or thermo-cautery point). In the case of ulcers of larger size covered with exudation, as well as in the case of deep infiltration of the cornea, moist and warm compresses, applied several times a day for one or two hours at a time over the closed eyes, prove most efiicient. With regard to the treat- ment of deep ulcers and of the cicatrices that follow ulcers, the general rules set forth under the head of affections of the cornea are applica- ble. A bandage should be applied only in case of imperative necessity (e. g., when there are ulcers penetrating deeply into the cornea) ; other- wise its use had better be avoided. It hinders the ready escape of the tears which are so copiously secreted, and, as it very soon becomes wet 7 98 DISEASES OF THE EYE. through with the secretion, it is liable to set up eczema of the skin of the lids. In conjunctivitis eczematosa, general treatment, conducted with due regard to the etiology, is of especial importance. The child's nourish- ment should be strengthening and administered at regular hours. Care must be taken that the dwelling place be dry and well ventilated, and the child should be sedulously kept out in the open air, irrespec- tive of any photophobia that may exist. Indeed, in any case, we must not yield too much to this symptom of photophobia, and it would be quite a mistake to keep children in a dark room just because they shun the light. As invigorating measures, spongings with cold water are of service ; also a sojourn in the country, especially at the mountains or the seashore. After the acute inflammation has run its course, the use of brine baths or of sea baths is of great service in preventing relapses. Unfortunately, the carrying out of all these regulations is only too often frustrated by the force of circumstances and by the poverty of the patients. The medicinal treatment of scrofula consists in the administration of cod-liver oil and of the preparations of iodine, iron, arsenic, and quinine. The sort of remedy employed and its dose must be adapted to each individual case. Furthermore, the cure of the eye disease is favorably influenced by treating any coexisting scrofulous affections, especially blepharitis, and also eczema of the face and of the nasal mucous membrane. In these affections the application of white-pre- cipitate ointment (one to two per cent) does good service. In blepha- ritis this ointment is smeared at night over the closed palpebral fissure. Eczematous spots upon the face are covered with a pledget of linen smeared with the ointment, and, to relieve eczematous coryza, the oint- ment is introduced from the anterior nares as far into the nose as pos- sible and rubbed in. For relieving moist eczema of the face, we can also employ with great advantage a five to ten per cent nitrate-of-silver solution applied with the brush, after removal of the crusts, to the raw cutaneous surface, which thus becomes covered with a thin eschar, under which the raw spots heal rapidly. This application must be repeated at first daily, afterward at intervals of several days, and be kept up as long as crusts continue to form. The synonyms which are used for conjunctivitis eczematosa, such as con- junctivitis phlycteenulosa, conjunctivitis pustulosa, herpes conjunctivse (Stell- wag), originate from the view that the efflorescence on the conjunctiva or cornea is a hollow vesicle filled with fluid ((jAvKTaiva [bladder], pustula, lieipes vesicle). But the efflorescence is in reality never a vesicle, but a solid, though soft, projec- tion, whicli is formed chiefly by an accumulation of lymphoid cells (Figs. 38 and 39). The softening and liquefaction of this cellular mass do not begin in the interior of the projection, but at its apex, so that there is no formation of a cavity (vesicle or pustule), but a loss of substance (ulcer) occurs, lying upon DISEASES OP THE CONJUNCTIVA. 99 the free surface at the apex. The name herpes cornefB, moreover, can give rise to a confusion with true herpes corner (herpes febrilis and herpes zoster, see § 40). In accord with the precedent set by the older authors, I formerly denoted con- junctivitis eczematosa under the name of conjunctivitis lymphatica (or scrofu- losa) on account of its undeniable connection with scrofulosis. Now, following many recent authors, I replace this etiological term by that of conjunctivitis eczematosa, which is indicative of the pathological anatomy of the disease, and thus denotes the nature of the morbid process. I do so because there are in- creasing indications for considering this affection of the conjunctiva as analo- gous to eczema of the skin. The latter, under the form of moist eczema, is, like conjunctivitis eczematosa, found particularly often in scrofulous children, being present especially upon the face and upon the edges of the eyelids themselves (blepharitis ulcerosa); and the nasal mucous membrane is also frequently at- tacked by it. This simultaneous occurrence on the skin and in the eye denotes in many cases a common origin from the scrofulous diathesis that is present ; but in other cases it is probable that the eczema develops in one spot and has been transferred from it to the other — i. e., from the skin to the eye or from the eye to the adjacent skin. Even in adults who have been attacked by a very ex- tensive eczema I have several times seen inflammations of the eye develop in the course of the disease, which were associated with marginal infiltrates of the cornea, and even led to perforation, and which therefore presented the picture of a severe conjunctivitis eczematosa. A certain proof of the identity of conjunctivitis eczematosa with ecze- ma of the skin will not be forthcoming until the same pathogenic agent has been proved to exist in both diseases. Up to the present time observers have been disposed to regard the staphylococcus pyogenes aureus as the agent in question, but further investigations are requisite in order to determine this point. The authors separate the eczematous aUeotions of the conjunctiva from those of the cornea; they speak of conjunctivitis and of keratitis eczematosa or phlyctfenulosa, of herpes of the conjunctiva and of the cornea, according as the efflorescence is located upon the conjunctiva or the cornea. In this way, for mere love of system, a picture of disease that, clinically speaking, is a perfect whole, is torn in two. In fact, we have here really but one single disease, which is localized sometimes in one place, sometimes in another. Frequently enough we find in the same eye, at the same time, an efflorescence in the conjunctiva; a second in the limbus, half in the conjunctiva and half in the cornea; and a third upon the cornea itself. Hence, in the foregoing description of the dis- ease the expression conjunctivitis eczematosa is employed for the disease in general, no matter upon what part of the surface of the eyeball it is localized. This can be done without doing violence to anatomy, inasmuch as the outer- most layer of the cornea must be looked upon as the continuation of the con- junctiva over the cornea. Accordingly, we can regard the involvement of the cornea in conjunctivitis eczematosa as an involvement of the "conjunctival layer " of the coi-nea. For the same reason pannus trachomatosus we regard as one of the symptoms of conjunctivitis trachomatosa, and not as an independent affection of the cornea. The differential diagnods between conjunctivitis eczematosa and the other affections of the conjunctiva and cornea is, as a rule, easily made. The char- 100 DISEASES OF THE EYE. acteristic mark of the former lies in the focal character of the affection as well as in its localization upon and immediately about the cornea. Only one other variety of conjunctivitis, the conjunctivitis ex acne, shares this peculiarity with conjunctivitis eczematosa; but that disease is readily distinguished from the latter by the accompanying acne rosacea upon the face (see infra). In vernal catarrh (§ 30) also little nodules occur upon the limbus, but never break down into ulcers; moreover, the palpebral conjunctiva, too, is diseased, and in a characteristic fashion. Of the diffuse inflammations of the conjunctiva, catarrh might be confounded with conjunctivitis eczematosa. For in intense and obstinate cases of conjunctivitis eczematosa the affection spreads to the palpebral conjunctiva, which may become very much reddened, swollen, or even velvety ; in that case a mucous or muco-purulent secretion forms upon the conjunctiva. It is often diflScult to distinguish between such cases and catarrh, especially if just at the moment of examination there are no characteristic efBo- rescences present upon the conjunctiva of the eyeball. Fortunately, a mistake in diagnosis does no harm, since, with such a condition of the conjunctiva existing, gentle cauterization with the nitrate-of-silver solution is always indi- cated, no matter what the origin of the disease. The pustular form of acute conjunctival catarrh forms a sort of intermediate stage between catarrhal con- junctivitis and conjunctivitis eczematosa (see page 48). Eczematous pannus is to be chiefly distinguished from pannus trachomatosus by the fact that an exact examination of the conjunctiva of the lids and of the fold of transition either discloses the changes of traclioma or establishes the fact of their absence. In regard to corneal ulcers which have been preceded by the efflorescences of a conjunctivitis eczematosa, it is sometimes impossible to recognize the fact of this origin with certainty, except when the ulcer is located at the very margin of the cornea and extends into the limbus conjunctivae, corneal ulcers as peripherally situated as this occurring only in connection with conjunctivitis eczematosa. The vascular fasciculus can readily be confounded with an ordinary corneal ulcer, to which, in tlie course of healing, vessels have made their way from the limbus so as to form a reddish-colored bridge be- tween the limbus and the ulcer. In such a case there is no fear of the ulcer's extending into the pupillary area of the cornea, and, after the ulcer heals, only a small, rounded macula is left, and not a long, opaque stria, as in the case of the vascular fasciculus. The distinction between these two affections can be made as follows : In the vascular fasciculus, the advancing margin of the ulcer, in- filtrated with gray, is readily visible; the blood-vessels as they run up to it lie in the furrow which the ulcer has channeled in the course of its progress — lie, therefore, at or below the level of the corneal surface. In the case of a simple ulcer with which a development of vessels has been associated, this fur- row and the opacity corresponding to it are wanting. In the treatment of conjunctivitis eczematosa calomel plays the greatest part. Since this remedy under its own form is insoluble in water, it was at first believed that a purely mechanical action should be ascribed to it (a scratching open of the efRorescenees, which were considered to be vesicles). But opposed to this view is the fact that indifferent powders, for instance, finely pulverized glass, which were also employed for inspersions, did not develop the same action. More recent investigations have proved that the action of calomel is a chemical onv. The calomel powder, when sprinkled into the eye, remains a long time in the conjunctival sac ; minute quantities of it are transformed by DISEASES OF THE CONJUNCTIVA. XOl the sodium chloride contained in the tears into corrosive sublimate,* which is thus continually being formed in small quantities, and exerts a steadily con- tinued action upon the conjunctiva. According to others, calomel itself is, to a small extent, soluble in a salt solution such as the tears represent, and is hence efficient under its own form. It -we undertake the inspersion of calomel in patients to whom at the same time iodine is being administered internally, we not infrequently observe a strong corrosive action from the calomel ; for the latter forms with the iodine excreted in the tears the very corrosive mercuric iodide (Schlafke). These two remedies, therefore, are incompatible with each other. A symptom that is especially tormenting for the patients is the photopTioUa 30 often connected with conjunctivitis eczematosa. In many cases this persists obstinately for mouths. The parents then bring the children to the physician, with the statement that they have been "blind " for such or such a number of weeks. The children offer the greatest resistance to the forcible opening of the eyes, especially when there are excoriations at the external commissure, which give pain and are prone to bleed when the lids are separated. Hence, in such cases the palpebral fissure is to be opened cautiously and not too wide, so as to avoid making the struggles of the children still greater. The lids, and espe- cially the upper lid, are rendered oedematous by the constant blepharospasm, because the veins of the lids, which pass between the fibers of the orbicularis, are compressed by persistent contraction of this muscle. Furthermore, a state of inversion of the lids (entropion spasticum) may be induced by this forcible squeezing together of the eyelids. Finally, cases have been described in which children who have suffered for a long time from blepharospasm were perfectly blind after the disappearance of this symptom (Von Graefe, Schirmer, Leber, and others). Such blindness is transient. As in most cases no objective changes were demonstrable as the cause of the blindness, no positive expla- nation for it can yet be assigned. In most cases the blepharospasm soon yields if the conjunctival trouble, which forms the basis of it, has been ameliorated by appropriate treatment. In case the spasm of the lid is particularly obstinate, Arlt's ointment (0.5 gramme of extract of belladonna to 5 grammes of blue ointment) may be rubbed into the patient's forehead and temples two or three times a dayj Instillations of cocaine, pretty frequently repeated, or douching the entire surface of the body with cold water every day, are also frequently of efficacy. Finally, we can even perform the operation of splitting the external com- missure (canthoplasty, see § 168), especially when the palpebral fissure has been abnormally contracted by reason of blepharophimosis. Herz has called attention to the -fact that many children who suffer from conjunctivitis lymphatica are infested with head lice, and that after doing away with these vermin the conjunctival disease, which hitherto may have been, obstinate, often heals with surprising rapidity. This is owing to the fact that head lice are among the most frequent causes of eczema of the hairy scalp. Beside eczema, the following exanthemata, both acute and chronic, are asso- ciated with diseases of the conjunctiva. [* According to some, however, calomel can remain in contact with tear fluid for an indefinite time without change. — D.] 102 DISEASES OP THE BYE. (a) Acute Exanthemata. Measles is regularly associated with a conjunctivitis. This appears under the form of an acute conjunctival catarrh, develops early (before the eruption of the exanthem upon the skin), and generally disappears of itself after two or three weeks without leaving any bad consequences behind. Only in exceptional instances does the conjunctivitis of measles take on a blennorrhoeal or even a diphtheritic aspect (without actually turning into true blennorrhoea or diphtheria). In such cases the cornea is endangered. During convalescence in some cases of measles, when the conjunctival inflammation had already become pretty slight, I have observed numerous Meibomian glands, both on the upper and the lower lids, becoming inflamed and suppurating (hor- deola meibomiaua, see § 108). The purulent contents were evacuated partly through the orifices of the glands, partly upon the inner surface of the lid after breaking through the tarsus and the conjunctiva. In variola, smallpox pustules not infrequently develop upon the conjunc- tiva, generally upon the tarsal conjunctiva near the intermarginal line. Small- pox pustules which develop upon the conjunctiva of the eyeball near the lim- bus are dangerous from their setting up a purulent keratitis in the adjacent part of the cornea — a condition which should not be confounded with the ulcus serpens that develops metastatically in smallpox (see § 36). (J) Chhonic Exanthemata. (1) Acne Rosacea Conjunctiva. — This disease of the conjunctiva, described by Arlt, begins as follows : A minute nodule forms, with moderate symptoms of irritation, upon the limbus. This efflorescence breaks down after some days, and the ulcer thus produced heals without leaving any visible cicatrix behind. This affection bears the greatest resemblance to the simple typical picture of conjunctivitis eczematosa, and shares with the latter its peculiar tendency to frequent recurrence. On this account it is very tormenting to the patient. It is possible to make the differential diagnosis chiefly from the fact that conjunc- tivitis ex acne attacks only adults and those who are at the same time affected with acne rosacea. It is important to make the correct diagnosis, since other- wise we might labor in vain to prevent the recurrences — a thing which can be done only by a suitable and long-continued treatment of the acne rosacea. The conjunctivitis itself is most speedily cured by inspersions of calomel. (3) Pemphigus Conjunctiva. — In this disease the conjunctiva, although red- dened as a whole, displays one or two spots that are deprived of their epithe- lium and covered with a gray coating. While these spots are slowly undergo- ing cicatrization — a process attended with shrinking of the subjacent conjunctiva — spots of the same nature appear in other places. Thus there is produced a constantly increasing cicatricial contraction of the conjunctiva, whose progress, it is true, is very slow (extending over months and years), but is irresistible. The conjunctiva becomes whitish, cloudy, and tense. First, the folds of transi- tion vanish, then folds make their appearance, stretching in a vertical direction from the lids across to the eyeball, and finally the lids are retracted so that trichiasis results. The conjunctiva at the same time grows continually drier and the lachrymal secretion dries up, owing to the fact that the excretory ducts of the lachrymal gland become occluded by the shrinking of the conjunctiva. Ulcers form upon the cornea, which later gets to be clouded all over, and DISEASES OP THE CONJUNCTIVA. 103 like-wise dry upon its surface. In the bad cases the lids at length become com- pletely adherent to the eyeball, so that the cornea is permanently covered by the lids and the eye is incurably blind (symblepharon totale). Hence, the prognosis of pemphigus is very unfavorable — the more so as both eyes are always attacked. In pemphigus of the conjunctiva, contrary to vfhat happens in pemphigus of the skin, bullae are only exceptionally found, their place being taken by denuded areas in the conjunctiva. This is explainable from the anatomical character of the latter. Its epithelium is so soft and delicate that it can not, like the epidermis, be lifted up in broad layers by serous exudation, but ruptures and is thrown off in the form of shreds ; hence the raw spots upon the conjimctiva, which soon become covered with a gray coating, as is so frequently the case in wounds of mucous membranes. Pemphigus of the conjunctiva is usually found in conjunction with erup- tions of pemphigus upon the skin. Still more frequently there exists with the pemphigus of the conjunctiva an analogous affection of the mucous membrane of the mouth, throat, or nose. In these localities the pemphigus runs a course like that in the conjunctiva and may, particularly in the buccal cavity, lead to shrinking of the mucous membrane, and thus to stenosis of the mouth. But it may also happen that a lesion of the kind just described exists in the conjunc- tiva without pemphigus being present elsewhere in the body. That such cases as these, which were first described by Von Graefe as essential" phthisis of the conjunctiva, are also to be ascribed to pemphigus, is not certain, though probable. Treatment has no power to restrain the process. Arsenic is administered internally for the pemphigus ; and to make the patient easier, mucilaginous remedies are instilled into the eyes as in xerophthalmus (see page 76). Trans- plantation of pieces from another mucous membrane into the conjunctival sac may be tried in order to replace the conjunctiva that has been destroyed. (3) Lupus Cojstjunctiv^. — Lupus of the skin sometimes is continued over the edges of the lids upon the conjunctiva. In this situation it appears as an ulcer, the bottom of which is covered with granulations in which tubercle bacilli can be made out. Lupus of the conjunctiva must therefore be regarded as a tuber- culous disease, for which reason reference for further details must be made to the article on tuberculosis of the conjunctiva (§ 20). In the case of other exanthemata, too, for instance in macular and papular syphilides, in pityriasis, psoriasis, ichthyosis, herpes iris, dermatitis herpeti- formis, lepra, etc., the conjunctiva is sometimes characteristically implicated. In lepra, nodules generally develop near the margin of the cornea, and subse- quently grow down into the subjacent sclera and also upon the cornea; when upon the latter they not infrequently have the appearance of a new growth. There is an associated iritis sometimes combined with the formation of lepra nodules in the iris ; also cyclitis. The nodules in the difierent parts of the eye finally break down, and the eye is lost. VI. Vernal Cataerh. 19. Symptoms and Course. — Vernal catarrh (Saemisch) is a chronic disease, persisting for years and setting up very characteristic changes in the conjunctiva, both of the tarsus and of the eyeball. The con- 104 DISEASES OF THE EYE, junctiva of the tarsus is covered witli papillae, which are broad and flattened, so as to make the conjunctiva appear like a pavement of cobble-stones. Over the whole lies a delicate, bluish-white film, as if a thin layer of milk had been poured over the conjunctiva. The changes in the conjunctiva of the eyeball are still more striking, although not so constantly present. Growths arise from the limbus at the outer and inner side of the cornea, under the form of brownish, uneven, hard nodules of gelatinous appearance. These extend partly into the transparent cornea for a short distance, and still farther in the opposite direction into the conjunctiva. In contradistinction to the nodules of conjunctivitis eczematosa, which break down so speedily, these nodules never ulcerate ; on the contrary, they are very stable bodies, often lasting for years with but slight variations in size. Quite as characteristic as the changes objectively perceptible are the statements given by the patients. They say that during the winter they experience little or no annoyance from their eyes, but as soon as the first warm days come in spring the eyes begin to grow red and to water ; the patients are greatly tormented by photophobia, and espe- cially by a constant itching in the eyes. The warmer the weather, the greater the intensity of the subjective troubles ; conversely, the patients feel easier if, for instance, there occur in summer a series of cool, rainy days. In autumn the troubles once more abate, and during the cold season they disappear completely, only to begin anew in the following spring. The difference in the objective condition at different seasons of the year is considerably less than one would suppose from the great change in the patient's subjective state, and consists principally in the eyes being free from discoloration in winter and injected in summer, while the growths upon the conjunctiva appear but slightly smaller in winter than in summer. Vernal catarrh is a pretty rare disease, chiefly affecting the male sex and the ages of boyhood and youth. Many patients seem to be in other respects quite healthy, while others, without being scrofulous, display besides pallor of the complexion multiple swellings of the lym- phatic glands, especially on the neck and lower jaw. Almost always both eyes are attacked. The disease generally keeps on making its return annually for three or four years, and often longer still, for ten or even twenty years, until finally it becomes extinct, without leaving any marked trace of its presence behind. The prognosis is therefore good as regards the ultimate outcome, but bad as regards the duration, as up to the present time we know of no remedy for curing the disease or for preventing its annual return. The cause of the disease is unknown. Inasmuch as we are unable to cure the disease, the treatment must be limited to the amelioration of the subjective symptoms. We com- bat the inflammation with the remedies used for acute and chronic con- DISEASES OP THE CONJUNCTIVA. 105 junctival catarrh. For the itching and photophobia, cocaine in two- per-cent sohition may be instilled. If the growths are of a considerable size they may be removed. Vernal catarrh is not a catarrh, as the not altogether suitable name choseu for it -would indicate, but is a disease sui generis. It was first described by Arlt (1846), who regarded it as a peculiar variety of conjunctivitis eczematosa. Subsequently Desmarres mentioned it under the title " hj'pertrophie perik^ra- tique," Von Graefe as gelatinous thickening of the limbus, Hirschberg as phlyctajna pallida. Saemisch first brought into prominence the characteristic exacerbation of the disease during the warm season, and therefore called it vernal catarrh, by which name it is at present commonly designated. Horner discovered the peculiar character of the tarsal conjunctiva, and thus completed the picture of the disease. The papillfB on the tarsal conjunctiva are hard — sometimes as hard as car- tilage. They are found to consist of a sort of areolar connective tissue, with a peculiar, hyaloid degeneration of the cells of the connective tissue and of the vessels. The epithelium covering the papillse is thickened, and to this is prob- ably due the macroscopically visible bluish-white film upon the surface which is characteristic of the disease. The growths upon the limbus consist of con- nective tissue, which is provided with very many cells and blood-vessels. Here, also, the epithelium is greatly thickened, and in places penetrates into the parts below, under the form of solid epithelial plugs (Horner, Vetsch). The growths are separated from the healthy cornea by sharply defined borders. In the cornea a slender gray stria, resembling the arcus senilis, may be seen, which runs parallel to the margin of the nodule, and is separated from it by a slender strip of transparent cornea. In the lightest cases of vernal catarrh it often happens that all the symp- toms are not present. Most frequently it is the growths upon the limbus that are wanting, the changes upon the tarsal conjunctiva alone being found. The latter are, hence, more important for the diagnosis of the disease. But there are also cases in which just the reverse occurs, i. e., tlie limbus is thickened, but the conjunctiva of the lids shows no characteristic changes. Some- times the only thing to indicate the presence of the disease is a peculiar, constant, tawny redness of the eyeball, made up of a coarse, reticulate conjunc- tival injection, combined with an evident ciliary injection. In such doubtful cases the diagnosis can be established only by the history, the specially char- acteristic features of which are the itching and the dependence of the symp- toms upon the external temperature. In severe cases the growths upon the limbus sometimes reach a considerable extent. They may even go entirely round the cornea, so that the latter is en- circled by a high, hard wall. In two cases I have seen the cornea itself quite extensively attacked by the morbid process. The first case was that of a six- teen-year-old boy, in whom a layer resembling a pannus, but pale, gelatinous- looking, and devoid of vessels, shot out over the cornea from the thickened limbus. In spite of all attempts to check by therapeutic measures the progress of the growth, the whole cornea was ultimately covered by it, and remained permanently clouded. In the second case, a Greek of thirty years of age, an analogous growth took place on the cornea of both eyes, although it did not cover the cornea completely, but left free on both sides a small central area, 106 DISEASES OP THE BYE. about corresponding to the size of the pupil. According to Van Millingen, such cases not infrequently come under observation in Constantinople, where the disease appears to occur much more often than it does here. The second case is also of interest because it concerned a grown man, while the disease ordinarily occurs only in youth. Quite small children are also exempt from it; there is only one instance of a one-year-old child being observed to suffer from the disease. The growths in the limbus might lead to a confusion of vernal catarrh with conjunctivitis eczematosa, the papillas upon the conjunctiva tarsi to a confusion with trachoma. The growths in the limbus are distinguished from the efflores- cences in conjunctivitis eczematosa, apart from their external appearance, chiefly by their unchangeable character during even a prolonged course of observation. The papillary outgrowths are most of all distinguished by their bluish-white coating, which is wanting in papillary trachoma. The history of the case is also of special importance in making the differential diagnosis. The extremely characteristic statements in regard to the fact of a return of the disease every year in the spring often establish the correct diagnosis before we have even looked at the eye. In hay fever, to be sure, there is also gener- ally a return of the conjunctivitis every year in the spring (see page 48). But this recurrence is an acute one, and runs its course within a few weeks, while, on the contrary, the symptoms of vernal catarrh last during the whole of the warm season. In the treatment of vernal catan-h I have found the instillation of a three- per-cent solution of boric acid and the inunction of a one to two per cent oint- ment of white precipitate, as recommended by Arlt, to be the most efficient means for alleviating the patient's sufferings. For the relief of the itching I often and with success use Van Millingen's prescription of dilute acetic acid (one drop of acidum aceticum dilutum to ten to twenty grammes of water) in- stilled into the eye several times a day. If the patient is one of the kind with pale face and swollen lymphatic glands, the exhibition of arsenic and iron internally is advisable. Amyloid Degeneration op the Conjdnotiva.— This rare disease has hitherto been observed only in Russia and the countries adjacent, and was first described by Oettingen in Dorpat. It consists in a peculiar degeneration of the conjunctiva, by reason of which the latter becomes yellowish, translucent like wax, nonvascular, and very friable. With this there is associated a consider- able thickening of the membrane, so that it forms large swellings which look like new growths. The affection begins in the retrotarsal fold, and from this passes over to the conjunctiva of the eyeball and of the lids ; in the lids the tarsus also is subsequently implicated in the degeneration. In a case that has lasted a long time the following clinical picture is found : The patient can not open the eye because the two lids, transformed into large, misshapen swellings, cover it up. If the lids are drawn as far apai-t as possible, the waxlike con- junctiva is seen rising up under the form of a rigid prominence all about the cornea, which latter is either clear or is covered by pannus. Thick swellino-s belonging to the retrotarsal fold, protrude between the lids and the eyeball ; the plica semilunaris also is enlarged until it forms a misshapen mass. These various swellings are so friable that they often tear when an attempt is made simply to separate the lids for examination, although in so doing they bleed DISEASES OF THE CONJUNCTIVA. 107 very little. The disease runs a very chronic course, dragging on for years without any real inflammatory symptoms, until at length the patient is deprived of the use of his eyes by his inability to open the misshapen lids. Microscopic examination has shown that the degeneration of the conjunc- tiva originates from the subconjunctival cellular tissue. This at first is found to be very abundantly infiltrated with cells (adenoid proliferation). This is followed by the formation in the tissues of dully lustrous, homogeneous bodies, which are called by the name either of amyloid or of hyalin, according to the reaction that they give with stains. Hyalin may occur as a preliminary stage in the development of amyloid; but generally it represents a variety of tissue degeneration {hyaline degeneration of the conjunctiva) distinct from the amyloid, and showing no tendency to pass over into the latter. Hyaline and amyloid degenerations present almost precisely the same clinical picture, so that a posi- tive distinction between the two can be made only by examining excised pieces of conjunctiva. Finally, calcification or ossification may take place in the degenerated mucous membrane. The disease attacks people in middle life, and ordinarily both eyes are affected. Very frequently amyloid degeneration is preceded by trachoma of the conjunctiva, which, however, should not be regarded as the cause of the affection, inasmuch as the latter can develop in eyes that previously were healthy. The actual cause of the disease is not known. In every instance it is a purely local process, for the individuals attacked by it are sound as far as the rest of the body is concerned, and do not suflier from amyloid degeneration of the internal organs, with which, therefore, amyloid degeneration of the con- junctiva has nothing at all to do. Medical treatment is powerless against this disease. We must confine our- selves to removing the growths upon the conjunctiva to such an extent that the lids can be opened and vision thus rendered possible. It is by no means neces- sary, indeed it is not at all advisable, to remove by a radical operation all the diseased parts, since the portion of the growth that is left behind generally atrophies of itself afterward. VII. TUBEKCULOSIS OF THE CONJUNCTIVA. 20. In the conjunctiva tuberculosis ordinarily appears under the guise of ulcers. Tuberculous ulcers are located as a rule in the tarsal conjunctiva. TJie diseased lid even on external inspection looks thick- ened. In everting the lid there appears upon its conjunctival surface an ulcer which is either covered by grayish-red granulations, or has a yellowish-red, lardaceous-looking base. In its vicinity small gray nod- ules (tubercle nodules) or outgrowths resenabling a cock's comb are often found in the conjunctiva. The ulcer shows no disposition to heal ; on the contrary, it spreads, although it does so very slowly. It may pass over to the conjunctiva of the eyeball ; and even the cornea is sometimes covered over by a sort of pannus. In especially severe cases the ulcer does not remain confined to the conjunctiva, but eats through the entire thickness of the lid, so that even on external ex- amination a deficiency of tissue is observable in the lid. Quite early in the disease the lymphatic gland in front of the ear becomes swollen ; 108 DISEASES OP THE EYE. afterward, the lymphatic glands about the lower jaw and in the neck also become enlarged. The clinical picture aSorded by the disease is thus pretty characteristic, although the diagnosis is to be considered as established only when fragments of tissue have been removed from the ulcer, and tubercle bacilli have been proved by the ordinary methods to exist in them, or when tuberculosis of the iris can be produced in rab- bits' eyes by inoculation with fragments of this sort. Tuberculosis of the conjunctiva generally attacks only one eye. The patient does not suffer pain; it is only by the swelling, of the lid, the purulent secretion, and subsequently by the diminution of visual power, that he is annoyed and made aware of the existence of his trouble. The disease occurs, almost without exception, in young peo- ple, and runs an uncommonly chronic course, being often protracted over many years. Even after an apparently radical cure it shows a great tendency to recur, and it can, by infecting the rest of the organ- ism, iinally lead to the patient's death from tuberculosis. The treat- ment in the cases where a complete removal of all the diseased parts seems still possible consists in the radical excision or curetting of the ulcer with a subsequent thorough cauterization, of the raw surface. The wounds made by the operation are s.trewn every day until they are com- pletely healed with finely powdered iodoform, a remedy which just in tuberculous processes is of particular efficacy. In some cases a cure has been effected by the injection of Koch's serum. Tuberculosis and lupus of the conjunctiva are to be looked upon as affections which are identical in their essential character, in so far as both represent ulcer- ative processes which are produced and maintained by the presence of tubercle bacilli. In fact, the first cases of tuberculous ulcers of the conjunctiva were described as primary lupus of the conjunctiva (that is, lupus of the conjunctiva without any coincident lupus of tlie skin) (Arlt). The two processes are dis- tinguished only by external points of difference relating to their outward aspect and their course. Thus, as a rule, lupous are distinguished from tuberculous ulcers of the conjunctiva by the fact that they have migrated from the skin to the conjunctiva, and that, like lupus of the skin, they show a spontaneous cicatri- zation on one side, while on the other the ulcer keeps advancing (see also p. 103). Tuberculosis of the conjunctiva may be primary or secondary. It is pri- mary if no sign of tuberculosis is present in the rest of the body at the time when the affection of the conjunctiva begins. In that case tuberculosis of the conjunctiva represents a purely local affection which has, without doubt, been excited by direct infection of the cdnjunctiva. A particle of dust containing bacilli gets into the conjunctival sac, and with its sharp angles produces a small superficial lesion of -the conjunctiva which is thus infected (tubercle bacilli, ac- cording to the researches of Valude, not penetrating into the conjunctiva when the epithelium is intact). In favor of an infection of this sort is the fact that we see tuberculous ulcers so frequently beginning in the region of the sulcus subtarsalis, where small foreign bodies are most readily retained. Some cases of primary tuberculosis have also been described, which originated in the con- junctiva bulbi and even in the cornea itself. DISEASES OP THE CONJUNCTIVA. 109 Primary tuberculosis of the conjunctiva may remain for a long time confined to the latter; indeed, in exceptional cases it may even heal spontaneously. The rule, however, is for tuberculosis to spread from here to the other parts of the organism. This extension may take place by way of the lymphatic circulation, the neighboring lymph glands becoming first affected with tuberculosis. Or, the disease may extend by continuity, the lachrymal passages first and subse- quently the nasal mucous membrane being infected by means of the tears which contain bacilli. Those cases of conjunctival tuberculosis are to be regarded as secondary in which either there is at the same time an evident tuberculosis of the internal organs (especially of the lungs) or in which tuberculosis is transmitted to the conjunctiva from places in its vicinity. A tuberculous affection of the nasal mucous membrane may be transferred to the conjunctiva by way of the lachry- mal passages. Not infrequently, therefore, we find conjunctiva, lachrymal sac, and nasal mucous membrane attacked at the same time by tuberculosis, and a careful study of the history of the case and an exact examination generally ren- der it possible to make sure whether the affection has passed down from the conjunctiva to the nose or vice versa. It is of the greatest importance for the prognosis and treatment to deter- mine whether tuberculosis is confined to the conjunctiva or not. In the former case we would regard the operation of removing thoroughly all the diseased parts as of very great value, since by it the patient may be permanently relieved of his tuberculosis ; while in the second case a radical cure is not to be thought of. Ulcers op the Conjunctiva. — Ulcers of the conjunctiva, besides occurring as a result of tuberculosis, are also observed in the following conjunctival affections : (a) As one of the symptoms of a conjunctivitis, an example being the minute ulcers originating in the eflioresceuces of conjunctivitis eczematosa or those which have given its name to the pustular form of catarrh. (J) After the separation of necrotic portions of the conjunctiva, as in diph- theria, or after burning of the conjunctiva with heat or caustics. Here belong also the eschars produced artificially by the use of too strong a])plications. (c) As a result of exanthemata ; ulcers, for instance, which are derived from a variolous pustule or from the rupture of a bulla of pemphigus upon the con- junctiva. {d) Upon the tarsal conjunctiva there is quite often found a small raw spot, from which rises a little mass of granulations. Here we have to do with a chalazion which has broken through on the inner side of the lid. As a rule, a slender sound can be introduced through the granulations into the cavity of the chalazion. (e) I have seen in some cases on the conjunctiva of the eyeball or the plica semilunaris, ulcers covered with a thick layer of pus, which were of acute origin. These were accompanied by violent inflammatory symptoms in the conjunctiva, and by swelling of the lids and of the lymph gland in front of the ear, and were associated with quite considerable pain. It seems to me that these should be attributed to infection from without, produced perhaps by the stings of in- sects or by small infected foreign bodies. Ulcers of this kind may also be pro- duced by the transfer of vaccine virus from a vaccination pustule. (/) Ulcers which have developed from the breaking down of epitheliomata of the conjunctiva. 110 DISEASES OP THE BYE. (g) Syphilitic ulcers. Generally we have here to do with those losses of substance which have arisen from the breaking down of an initial sclerosis. These, as a rule, are situated near the free border of the lids, but are also ob- served in the retrotarsal fold and even in the conjunctiva of the eyeball. The transmission of syphilis appears to take place most frequently by kissing, and in small children also by the practice which many nurses have of moistening the agglutinated edges of the lids with saliva in order to open them. Occa- sionally, also, syphilitic ulcers have been observed, which were produced by the breaking down of gummata of the conjunctiva (Hirschberg). Syphilitic ulcers of the conjunctiva are among the greatest of rarities. VIII. Injuries of the Conjunctiva. 21. The following varieties of injuries of the conjunctiva, which are of such frequent occurrence, are observed : (a) Foreign bodies in the conjunctival sac. Small-sized foreign bodies, like grains of dust, particles of coal or of ashes, which so often get into the eye during a railroad journey, the wing cases of small beetles, etc., fall first upon the surface of the eyeball, are brushed away from this spot by the movements of the upper lid, and then generally stick to the inner surface of the latter at a spot not far from its free border, where a shallow furrow, the sulcus subtarsalis, runs parallel to the edge of the lid and catches the foreign body. The pain which such a foreign body causes, and which is often quite considerable, does not originate in the conjunctiva itself, which has very little sensitiveness, but in the cornea, inasmuch as with every movement of the lid the foreign body is carried over the cornea and scrapes it. Hence the pain is absent as long as the eye is kept quietly closed. It is easy to remove the foreign body after the lid is everted. In other cases, small, sharp-pointed foreign bodies penetrate into the conjunctiva, and may remain there a long time. Grains of pow- der remain fixed in the conjunctiva of the eyeball without giving rise to any further irritation, and may therefore be left in the conjunctiva. Larger-sized foreign bodies are retained in the conjunctival sac only when they get into the upper retrotarsal fold. In this spot they stay, remaining still even during the act of winking, cause no irritation of the cornea, and therefore produce but little trouble. After some time has elapsed they begin to excite the symptoms of chronic conjunctival catarrh. (b) Solutions of continuity of the conjunctiva are not rare, and often associated with extensive infiltration of blood (ecchymosis). If the edges of the wound are not too greatly lacerated, the conjunctival wound can be closed with a stitch. (c) Burns of the conjunctiva and injwies ly caustics arc pretty fi^equent. Burns are the result of hot water or steam, hot ashes (espe- cially cigar ashes), exploding powder, flames striking against the eye, DISEASES OF THE CONJUNCTIVA. m molten metal, etc. Of the injuries by caustics, which may be produced both by acids and by alkalies, those that arise from the action of lime are the most frequent, the lime getting into the eye usually under the form of mortar. The action of burns is the same as that of caustics; the conjunc- tiva at the affected spots is destroyed and converted into an eschar. These spots stand out as gray or white patches in the midst of the reddened and swollen portions of the conjunctiva that are not escha- rotic. The eschars separate in consequence of a delimiting suppu- ration, and the resultant granulating losses of substance in the con- junctiva heal by a drawing in over them of the neighboring healthy conjunctiva. The final result is therefore always the formation of a cicatrix. This can lead to a diminution in size of the conjunctival sac, or, if of great extent, to adhesion of the lids to the eyeball (sym- blepharon). The prognosis of an injury by burns or caustics with regard to the preservation of sight depends primarily upon the condition of the cor- nea, which, indeed, is always simultaneously affected when there is an extensive lesion of the conjunctiva. Next, although of secondary consequence, the losses of substance in the conjunctiva itself must be considered, inasmuch as the adhesions that develop from them may cause subsequently more or less disturb- ance of the function of the eye. The prime tlierapeutic requisite, when we get an eye under treat- ment a short time after it has been injured by caustics, is the com- plete removal of any corrosive substance that may still be present. We remove solid particles with a pledget of linen or with a forceps, and then wash the conjunctival sac out thoroughly. For this latter pur- pose we use, as far as possible, such solutions as shall neutralize the corrosive substance or render it insoluble, and so jDut a stop to its in- jurious action. In the case of caustic alkalies we do not use water, but milk. In burns produced by lime our best plan is to wash the eye out with oil and afterward to drop in a concentrated solution of sugar, since cane sugar forms with lime an insoluble compound. In the further course of an injury produced by burns or caustics, it is incumbent upon us to restrain the subsequent inflammation by means of cold compresses, atropine, the application of a bandage, etc. After the separation of the eschars, our aim must be to confine the resulting adhesions within the smallest possible limits. For this pur- pose we repeatedly draw the lids away from the eyeball in order to prevent the adhesion of the two opposite raw surfaces. If the loss of substance extends so far as to implicate the retrotarsal fold, an adhe- sion between the lid and eyeball, starting from the fornix (symbleph- aron posterius), can not in any way be avoided. Such an adhesion must be removed, as far as can be done afterward, by operative measures. 112 DISEASES OP THE EYE. Sometimes foreign bodies are introduced into the eye purposely. Chief among those thus used are what are called crab's eyes — the lapides cancrorum. These are flat, calcareous concretions derived from the stomach of the crab, ■which are in great favor among the laity as a means of removing foreign bodies from the eye. The crab's eye is introduced between the lid and the eyeball, and then is pushed across the cornea, carrying with it, it may be, mechanically any foreign body that chances to be there.* Sometimes it happens in the per- formance of this manipulation that the crab's eye slips into the superior fornix and remains there unnoticed. We may then find it there months or even years afterward, entirely imbedded in the outgrowths of the conjunctiva, which has undergone chronic inflammation. Foreign bodies, such as sand, ashes, and the like, are also intentionally in- troduced, for the purpose of simulating an eye disease, into the eye, where they set up a conjunctival catarrh. With regard to the presence of caterpillar's hairs in the conjunctival sac, see § 74 (Ophthalmia nodosa). After the action upon the eye of irritant substances, consisting either of acrid vapors or of liquids which are injected into it, an acute traumatic con- junctivitis is produced, evidenced by intense reddening of the conjunctiva with great photophobia, lachrymation, and pain, with which is associated in violent cases an oedematous swelling of the lids. A similar picture is presented by that variety of conjunctivitis which occurs after the action of intense light upon tlie eye, as, for example, after dazzling by the reflection from snow (snow blindness), or by the electric arc light (ophthalmia electrica). In violent cases of this sort there are found, besides the inflammation of the conjunctiva, con- traction of the pupil and also slight opacities and erosions of the cornea. These symptoms, like the erythema of the skin occurring as a result of insolation, are produced by the action of the ultra-violet, chemically active light rays (Wid- mark). These cases of traumatic conjunctivitis, in spite of the violent symp- toms which they present in their beginning, generally get well within a few days without further bad results. IX. Pterygium. 22. Symptoms and Course.— A pterygium is a triangular fold of mucous membrane which extends from the conjunctiva of the eyeball to the cornea, either at the inner or the outer side of the latter (Flo-. 30). The apex of the triangle lies in the transparent portion of the cornea, and is solidly and immovably united to it. The base of the triangle spreads out in the conjunctiva of the eyeball, and passes into it without there being any sharp line of division between the two. The apex is called the head, the base the body, of the pterygium. The part that lies between the two and corresponds to the margin of the cornea is the neck of the pterygium. Here the limits of the fold of conjunctiva are the most sharply defined, as its borders are rounded in such a way that a small sound {S, Fig. 30) can be pushed beneath them * [In I his country eyestones (the flat operoula of certain mollusca) are used for the same purpose. — D.] DISEASES OP THE CONJUNCTIVA. 113 =v^ ^^^'n]'\'-v^ =^f. Fig. 30.— Pterygium. A sound, S, IS carried beneath the edge of the pterygium, P. The dotted line shows the way in which the section is made in re- moving the pterygium. C, caruncle. The adjacent plica semilunaris has been flat- tened out by the tensive force of the ptery- gium, and is hence invisible. P, upper punctum lacrimale. for a short distance. A pterygium of recent origin is succulent, and abounds in vessels which run converging from the base to the apex and impart to the pterygium its red color. In fact, from its similarity in form and vascularity (venation) to the wings of many insects (Hymen- optera), the name of pterygium is derived.* The fold of conjunctiva forming the pterygium is tightly stretched, so that there are produced a number of radially disposed fur- rows or fiutings; furthermore, in pterygia which are situated at the inner side of the eye the jDlica semi- lunaris is often quite obliterated and is included in the body of the pterygium (Fig. 30). In the course pursued by a ptery- gium two stages must be distin- guished. In the first the pter5'gium keeps on gradually growing, for years it may be, toward the center of the cornea, which it may finally reach or even pass {progressive pterygium). Finally, the pterygium comes to a standstill so as to remain permanently attached to the same point upon the cornea {stationary pterygium). Whether in any given case we are dealing with a progressive or a stationary pterygium is de- termined mainly by the character of the apex of the growth. In the progressive stage this appears surrounded by a gray non-vascular zone which looks' thick and gelatinous. In a stationary pterygium this mar- ginal zone is found to be thin and cicatricial looking and the whole pterygium is thin, pale, nearly destitute of vessels, and tendinous. Pterygium occurs only in that part of the cornea corresponding to the interpalpebral fissure. It is found most frequently on the inner side of the cornea ; when there is one in this spot already another may form on the outer side also. The two pterygia may even meet in the center of the cornea. A genuine pterygium is practically never ob- served at the upper or the lower margin of the cornea ; on the other hand, it is not infrequently the case that both eyes are attacked simul- tanepusly by pterygium, so that we sometimes see patients who have four pterygia, one on the outer and one on the inner side of either cornea. Among the injurious results which a pterygium entails, the worst is the damage done to the eyesight. This begins to be produced as * Prom [irrepiytov, the diminutive of] irrepv^, a wing. 114 DISEASES OP THE EYE. soon as the point of the pterygium projects into the pupillary area of the cornea, and it increases in proportion as the point approaches the center of the latter. Moreover, pterygium by the tension to which it gives rise often causes a condition of irritation in the eye, as is shown by the marked injection and succulence (catarrhal inflammation) of the pterygium itself. In addition, the membrane, particularly if very much reddened, forms a striking disfigurement and can also cause a re- striction of the mobility of the eye. If, for example, a pterygium is situated on the inner side of the cornea and the eye is meant to be turned strongly outward, the eye may be restrained in its movement by the tension of the pterygium, and therefore fail to move laterally as far as the other or healthy eye, so that binocular diplopia may be pro- duced in consequence of this faulty placing. Etiology.— A pterygium is nothing but a fold of conjunctiva drawn np over the cornea and fastened to it. It originates from the Pinguec- ula, the degenerative process which exists there making its way into the limbus, and then gradually upon the cornea itself. The pinguecula, therefore, grows up, as it were, over the cornea, and in so doing draws the conj unctiva after it. Since the pterygium originates in the Pinguec- ula, it is evident why, like the latter, it should occur only at the inner and outer margins of the cornea. And as the pinguecula develops in consequence of the injurious influences which the conjunctiva in the region of the palpebral fissure is exposed to in the course of years, the like is true of pterygium and in a still greater degree. Hence it is found only in elderly people,* and in them especially when they are much exposed to wind or dust, as in the case of country people, coach- men, masons, stonecutters, etc., while among the well-to-do classes pterygium belongs among the rarities. The forcible traction which the conjunctiva exerts upon the cornea explains the triangular form of the fold, its incurved margin, and its great tension in a horizontal di- rection. Treatment. — The treatment of pterygium consists in its ablation by Arlt's method. With a toothed forceps we grasp the pterygium at its neck, where the incurving of its margin permits it to be partially lifted from its bed. Starting from this point, we carefully dissect ofi the head from the cornea, upon which it lies, keeping strictly to the line of division between the tissue of the pterygium and the cornea. We must be particularly cai-eful to remove thoroughly the gray, gelatinous zone at the apex of the pterygium, scraping or curetting the surface when necessary to complete the abscission. When the whole of the head as far as the limbus has been separated from the cornea we circumscribe this segment by carrying from the upper and lower margins of the neck [* But in this country at least is observed in comparatively young persons. Thus I have seen it in a boy of nineteen. — D.] DISEASES OP THE CONJUNCTIVA. 115 two converging incisions into the body of the pterygium (the dotted line, Fig. 30). In this way a rhomboidal piece, containing the head and part of the body, is excised and a raw surface remains, one portion of which lies in the cornea, the other in the conjunctiva of the eyeball. This last is covered by uniting the upper and lower margins of the sec- tion by means of one or two interrupted sutures. The wound in the cornea heals by a cicatrix forming over it, in consequence of which a permanent opacity remains. Care in sewing up the conjunctival wound is of the greatest importance, especially in the neighborhood of the limbus, as otherwise the conjunctiva grows anew over the raw surface of the cornea, and thus the pterygium recurs. However, even after carefully performed operations relapses are not infrequent, and then a second removal is required. Ablation is indicated in every case of progressive pterygium. Even though the pterygium is still small, we can not be sure that it will not grow on into the pupillary area of the cornea. Hence we prefer by per- forming ablation to guard in time against injury to the eyesight. If the pterygium has approached sufficiently near the center of the cornea to cause disturbance of vision, this disturbance is indeed rendered less by the operation of ablation, but is not completely done away with, since those spots of the cornea, which were occupied by the pterygium, never again become perfectly transparent. In any case, the associated symptoms of irritation, the restriction of mobility, and the disfigure- ment are removed by the ablation. A stationary pterygium does not necessarily require ablation ; in this case we shall be guided mainly by the wishes of the patient with reference to the removal of the disfig- urement, etc. The older writers distinguished a pterygium crassum (vasculosum, carno- sum, sarcomatosum) and a pterygium tenue (membranaceum). Tlie former cor- responds to a catarrhally inflamed, and hence'therefore red and thick pterygium, the latter to a stationary pterygium, which has become thin and tendinous. A pterygium has been shown to be histologically identical with the conjunc- tiva of the eyeball, of which indeed it is only a drawn-out and projecting fold. It consists mainly of fibrillar connective tissue, which is covered with the epi- thelium of the conjunctiva. The apex of the pterygium, however, is often covered by the corneal epithelium, so that the pterygmm may be said to force its way underneath the latter. In the tissue of the pterygium are found new- formed tubular glands and also larger spaces lined with epithelium ; from both of these small cysts may develop. Bowman's membrane, where it lies beneath the pterygium, is destroyed ; indeed, the uppermost lamellae of the cornea even are replaced here and there by the tissue of the pterygium. This explains why, even after the ablation of the pterygium, the cornea does not regain its normal transparency. Arlt deserves the credit of having made the operation for pterygium a suc- cess by demonstrating the necessity of closing the conjunctival wound. Pre- viously people had been satisfied with simple ablation, and had so frequently 116 DISEASES OF THE EYE. had recurrences after this operation that with many it had altogether fallen into disrepute. In very broad pterygia it is difficult or impossible to unite the edges of the conjunctival wound by a suture. In that case liberating incisions are made through the adjacent conjunctiva in order to facilitate the process of drawing it down ; and, instead of cutting oflE the point of the pterygium, it may be sewed into the gaps which have been made by the liberating incisions. PsBUDO-PTEETGiUM (CICATRICIAL Ptekygitjm). — Sometimes we observe as a result of inflammatory processes fixation of a fold of conjunctiva upon the cornea, giving a picture similar to that of true pterygium. For example, there may be an acute blennorrhoea of the conjunctiva, with great chemosis, and a pretty large marginal ulcer of the cornea. The chemotic protuberance of the conjunctiva becomes applied to the surface of the ulcer and adheres to it. After the inflammation has abated, the swelling of the conjunctiva goes down, the chemotic protuberance disappears; but, in the spot where union of the cornea has taken place, the conjunctiva remains permanently fixed to the latter. We then see a triangular fold formed of conjunctiva extending over the limbus and upon the cornea, and attaching itself there. Ordinarily, at that part of the fold corresponding to the limbus a fine sound can be passed all the way beneath the fold, a sign that the latter is adherent to its bed at its apex only and not throughout its whole extent. This is the most important distinguishing mark between a true and a false pterygium ; another consists in the fact that a pseudo- pterygium does not keej) on growing over the cornea, as a true pterygium does, but remains steadily fixed to the spot at which it first became adherent. In its origin and its behavior a pseudo-pterygium is more like a symblepharon than a genuine pterygium. Pseudo-pterygia are observed not only after acute blennorrhoea, but also after diphtheria, burning by heat and by caustics, prolapses of the iris, the re- moval of new growths, etc. It is evident that they may develop not only at the outer and inner sides, but at any side whatever of the cornea. The pseudo- pterygia remaining after acute blennorrhoea are usually found above, those pro- duced by burns, etc., most frequently at the lower part of the cornea (the re- gion corresponding to the palpebral fissure). Another kind of pseudo-pterygium is that which develops after a chronic superficial ulceration of the marginal portions of the cornea (keratitis margina- lis superficialis, Fig. 51). Owing to the cicatrization which follows the ulcera- tive process the conjunctiva is steadily drawn up over the cornea. These pseudo-pterygia are very similar to true pterygia, for like the latter they keep on growing slowly over the cornea, and unlike other pseudo-pterygia are not completely perforate at the limbus. The differential diagnosis between these and the true pterygia can be made only in case we find the ulcerative process or its sequelae (a superficial corneal opacity) upon the marginal portions of the cornea not implicated in the pterygium. Small pseudo-pterygia may without disadvantage be left undisturbed- larger ones we generally remove in the same way as genuine pterygia and unite with stitches the wounds left in the conjunctiva. In those cases in which the pseudo-pterygium is not adherent to the surface of the eyeball at the spot cor- responding to the limbus, ablation and the use of the suture may be dispensed with ; it is sufiicient simply to free the point of the pseudo-pterygium from the cornea, upon doing which the former retracts of itself and disappears by a process of atrophy. DISEASES OP THE CONJUNCTIVA. 117 It sometimes happens that an old pannus which has already been trans- formed into connective tissue is united to the subjacent cornea only by loose cellular tissue, and thus acquires a certain freedom of movement, so that it can be shifted this way and that upon its bed along with the conjunctiva of the eyeball. In this way too, then, a picture similar to that of a pterygium may be produced. X. Stmblephaeon. 23. Symptoms. — By symblepharon * we understand a cicatricial adhesion between the conjunctiva of the lids and the conjunctiva of the eyeball. In that case, when we attempt to draw the lid away from the eyeball, we observe that in one or more places bands extend from the inner surface of the lid to the surface of the eyeball, and that these become tightly stretched and prevent us from drawing the lid away completely. These bands generally look tendinous, more rarely fleshy, and may be attached not only to the conjunctiva sclerse, but also to the surface of the cornea itself. If the adhesion between the two con- junctival surfaces extends so far peripherally as to reach into the fornix, we call this symUeplmron posterius (Fig. 31 B). If the adhesion does Fig. 31.— Symblepharon (Schematic). A, symblepharon anterius; B, symblepharon posterius by adhesion; C, symblepharon posterius by cicatricial shrinking ; /, fornix. not extend as far as this, so that the cicatricial bands stretch like a bridge between the lid and the eyeball, and we can introduce a sound beneath them and carry it along the fornix between the lid and the globe, it is then called symllepharon anterius (Fig. 31 A). This distinction has been established for practical reasons, inasmuch as symblepharon anterius can be readily cured by an operation, while symblepharon posterius can be cured with difficulty or not at all. SymilepTiaron totale is a total adhesion between the lids and the eye- ball — a condition which occurs but rarely. Etiology. — Symblepharon develops whenever two opposed spots of the conjunctiva of the lid and of the eyeball have raw surfaces which * Prom aiv, together, and fi\e(papoy, eyelid. 118 DISEASES OF THE EYE. come into contact with each other, and in consequence become adher- ent. Such a process of adhesion results of necessity when the two raw surfaces extend up into the fornix and there pass into each other, since two raw surfaces which meet at an acute angle always begin to unite at this angle of junction. Causes which can give rise to the formation of raw surfaces ujDon the conjunctiva are burns by the action of heat, burns from caustic substances, diphtheria, operations, ulcers of all kinds, etc. The expression symblepharon is also employed in a somewhat dif- ferent sense to denote the contraction of the conjunctiva which occurs as a result of its gradual shrinking^ as, for instance, after trachoma (see page 71). In this case it is not a question of an adhesion between two raw conjunctival surfaces, but of a gradual diminution in size of the conjunctival sac. The folds of the region of transition are first smoothed out ; the conjunctiva of the lid extends directly to the eye- ball (Fig. 31 C), and whenever the lid is drawn away is made tense and drawn out into transversely disposed folds. In advanced cases the conjunctival sac is converted into quite a shallow groove between the eyeball and the lid. Since contraction of the conjunctival surface in consequence of shrinking always makes itself first apparent by disap- pearance of the retrotarsal fold, all these cases belong to symbleph- aron posterius. This kind of symblepharon is observed principally after trachoma ; furthermore, in the rare cases of pemphigus of the conjunctiva. Very light cases of symblepharon produce no bad results worth mentioning. When there are more pronounced adhesions, the excur- sions of the eye are hindered, and thus possibly diplopia may be pro- duced just as in the case of pterygium. Inasmuch as with the move- ments of the eye traction is made at the site of the adhesions, the eye gets to be in an irritated condition. If the adhesions extend into the region of the palpebral fissure they become disfiguring, and if they extend as far as the cornea they may injuriously affect the sight. Sometimes the lids are so fastened down by extensive adhesions that their complete closure is impossible, and lagophthalmus is produced with its consequences that are so baneful to the cornea. Total sym- blepharon is obviously associated with complete blindness (or at most with quantitative perception of light). Treatment.— This involves an operation. Cases of symllepliaron anterius are easily cured. "We separate the adhesions between the lid and eyeball with great care, so as not to cut into the sclera or the tarsus. When the lid has been set free, we must then make it our business to prevent a readhesion of the freshly made raw surfaces, and to make each of these cicatrize by itself. This is effected by repeatedly drawing the lid away from the eyeball, and also by interposing a pledget dipped in oil or smeared with ointment between the lid and the eye. DISEASES OF THE CONJUNCTIVA. 119 :{^^.4hl^ 111 symblepliaron posteriiis we also begin by separating the adhe- sions as far back as tlie fornix. "We tlien see, when we have drawn the lid away from the eyeball, two corresponding raw surfaces, one in the eyeball, the other on the lid (Fig. 32). These two opposed sur- faces, which meet at the fornix, would soon reunite, beginning at the fornix, if we did not take care to have one of the raw surfaces covered with conjunctiva, so that a place coated with epithelium lies opposite to the raw surface remaining. The wound on the eyeball is the one we select for covering over, because the conjunctiva of the eyeball can readily be displaced, while the conjunctiva of the lid is adherent immovably to the tar- sus. We loosen the conjunctiva of the eye- ball on both sides of the wound, draw it down over the latter, and unite it by sutures. Especial care must be devoted to uniting the wound in the neighborhood of the fornix. If, after dividing the adhesions, the raw sur- face upon the eyeball is so large that it can not possibly be covered by conjunctiva, re- union of the symblepharcn will inevitably result. Hence, cases of extensive symblepharon posterius, and obviously also cases of symblepharon totale, are incurable. The same is true of symblepharon induced by the gradual shrinking of the conjunctiva. Fig. 32. — Operation for a Sym- blepharon Posterius. The wound in the palpebral con- junctiva (a) has been left open, that in the bulbar conjunctiva closed by two interrupted su- tures. In order to be able to draw the conjunctiva up over the raw surface, a liberating incision has been made along the margin of the cornea, in- ward and outward from the upper end of the wound. We sometimes also operate for symblepharon in the case of a blind and shriv- eled eye so as to be able to introduce an artificial eye over it. Different methods have been devised to enable us to operate for cases of symblepharon posterius with extensive adhesion. Himly, in an operation analo- gous to that for syndactylism, first made a preliminary perforation of the adhe- sion along the fornix, and carried a lead wire through the canal so formed. The latter, after the wire has been in it a pretty long time, becomes covered with epithelium (like the canal made by piercing the lobule of the ear for ear- rings), so that the symblepharon posterius is changed into a symblepharon an- terius, and can be operated upon, like the latter, by simply separating the adhe- sion. Some have attempted to cover a large loss of substance upon the eyeball, caused by the removal of a symblepharon, by making the conjunctiva that is to be drawn up over it movable by means of liberating incisions, or by fashioning pedicellate flaps out of conjunctiva and attaching them to the wound (Teale, Knapp). Others (Stellwag, Wolfe) have grafted nonpedicellate flaps formed out of bits of mucous membrane from other localities (the conjunctiva of the other eye, the mucous membrane of the lips, or that from the mouth or vagina, or even the mucous membrane of animals) upon the raw spot, and have obtained union. Others again, for covering a loss of substance, take the external skin 120 DISEASES OF THE BYE. either in the form of small flaps grafted upon the surface, or as pedicellate flaps which are thrust in between the eyeball andy the lid through a fenestra cut through the latter (Kuhnt, Snellen). Generally speaking, we are obliged to acknowledge that in extensive adhesions all methods have but scanty results to offer, since the symblepharon commonly returns on account of the subsequent shrinking of the conjunctiva. XI. Xerosis. 24. Symptoms. — Under the name of xerosis * conjunctivae we desig- nate an alteration of the conjunctiva, the essential character of which is that the latter is dry. The surface of the conjunctiva at the xerotic spots shines like fat and is of a whitish color, and looks either like epi- dermis or as if it were covered with dried foam. In such places the conjunctiva is thicker, less pliable, and lies in stiff folds. The tears flow over the diseased spots without moistening th'em. An analogous change is also observed in the cornea, the surface of which looks dull, lusterless, and dry, while the parenchyma of the cornea at the same time is found to have lost its transparencj' (xerosis cornese). Etiology. — The cases in which xerosis is observed are divided into two groups. In the first, xerosis is the result of a local affection of the eye ; in the second, it is an accompanying symj)tom of a general disease. Xerosis resulting from a local affection of the eye is found : (a) In cicatricial degeneration of the conjunctiva. It is observed most frequently as the final outcome of trachoma, and also, but more rarely, after dijihtheria, pemphigus, burns, etc. It begins in isolated spots, but may ultimately spread over the entire conjunctiva, and over the cornea also. In the latter case, since the xerotic cornea grows opaque, the eye becomes blind. This form of xerosis is incurable. {fi) Deficient sheltering of the conjunctiva, so that the latter is con- stantly in contact with the air, can likewise lead to xerosis. This occurs in ectropion and in lagophthalmus (incomplete closure of the lids). In the former case the exposed portion of the tarsal conjunctiva, in the second case that part of the scleral conjunctiva and of the cor- nea lying in the course of the palpebral fissure, becomes covered with a thickened, dry, epidermoid epithelium, by means of which these parts protect, so to speak, their deeper layers against desiccation. In such cases assistance can be rendered only when it is possible (by operative interference) to provide the exposed conjunctiva or cornea with its normal shelter again. Xerosis, resulting from a general disease, occurs under a light and a severe form : (a) The light form is associated with hemeralopia (night blindness). Simultaneously with the peculiar disturbance of vision (see § 104) there * From ir,p6s, dry. DISEASES OF THE CONJUNCTIVA. 121 are found on the outer and inner side of the conjunctiva bulbi small triangular spots, which are covered with what resembles fine dried foam, and which are not moistened by the tears (Bitot). This form of the disease attacks adults. (b) The severe form is associated with keratomalacia (see § 38). Here also xerosis makes its appearance first in the region of the con- junctiva corresponding to the palpebral fissure, but subsequently it spreads to the cornea, which breaks down into pus. The disease attacks children only, who often die with the symptoms of a severe general disease. It is conjectured that the light and the severe form are but different grades of one and the same disease, the essential nature of which is still unknown to us. The xerosis, which in these cases attacks a hitherto perfectly healthy conjunctiva and cornea, must be looked upon as a consequence of the disturbance of nutrition produced by the disease. Its particular importance to us, therefore, is as a symptom of this general affection, against which, accordingly, treatment must be particularly directed. The separation, first made by Cohn, of xerosis into a variety dependent upon local causes and one caused by a general disease corresponds nearly to the ordinary division into xerosis parenchymatosa and xerosis epithelialis. In local xerosis the mucous membrane is diseased in its deeper as well as in the superficial layers (xerosis parenchymatosa); while in xerosis produced by a general disturbance of nu- trition the change affects the epithelium only (xero- sis epithelialis). Many also make a distinction be- tween xerosis partialis (sive glabra) and xerosis totalis (sive squamosa). Fia. 33.— Xerosis Conjukc- The anatomical changes which form the basis ^'^^ Magnified 820 x l. of xerosis principally affect the epithelium. The ^P'j;?^{i?'eon]uTo?fvl'l?a'J^^^^^ uppermost layers of eT)ithelial cells undergo kera- affected with keratomalacia. , . ,, , , \. ,, T. , Colored by Gram's method, tosis, the protoplasm of the succeedmg layers con- The nucleus of the cell is taining abundant granules of keratohyalin (Fig. 33). ^!g^^^ ZmJr'^ustln- In consequence the epithelium appears thickened, "'«« "f keratohyalin lymg m . ^ '^ ^ ^ . .' the protoplasm of the cell. whitish, cloudy, and epidermoid. Moreover, it is Upon the cell are seen xero- covered with the sebumlike secretion of the Meibo- fn^size! 'The'iarger-'siledba^ mian glands, and hence assumes a fatty character, "^i"' ''f^.,''"**'°SV^\ biscuit- ° ' J J shaped ; the smallest ones re- in consequence of which the laclirymal fluid does semble oblong cocci. not adhere to it. To this circumstance the peculiar dry appearance is chiefly owing, for if the diseased spots are freed from their fat by the application of soap they become capable of being wetted by the tears (Leber). Reymond and Colomiatti and shortly afterward Kuschbert and Neisser de- scribed as occurring in xerosis a special micro-organism, the bacillus of xerosis, which is extremely like the diphtheria bacillus. This is found under the form of short rods adhering in great quantities to the surface of the epithelial cells. It is, however, neither the cause of xerosis, nor indeed characteristic of the latter. It occurs frequently in the conjunctival sac at all times, and simply 122 DISEASES OF THE BYE. seems to find in the dying epithelium of the xerotic spots a specially favorable soil for growth, so that it develops there in great quantities (Fig. 33.) In any ca^e, it can not be the special exciting cause of the disease; on the contrary, we must assume that coming from the air it gets upon the conjunctiva, and finds in the epithelium of the latter a soil favorable for its growth, whenever this epi- thelium has had its nutrition injuriously affected. What part does the lachrymal secretion play in xerosis ? The real cause of the dryness of the conjunctiva is not, as has been believed, the deficiency of tears. In the beginning of the disease, as long as only small isolated spots of the conjunctiva are xerotic, we often find actually an increase in the lachrymal secretion. Per contra, xerosis of the conjunctiva has never been known to occur after extirpation of the lachrymal gland. The real cause of the dryness of the conjunctiva is rather the fact that the tears do not adhere to it. Never- theless it is true that in advanced xerosis the lachrymal secretion diminishes, and may even disappear altogether, for, owing to the marked shrinking of the conjunctiva, the excretory ducts of the lachrymal gland, which empty in the upper retrotarsal fold, are closed, and as a result of this, atrophy of the gland itself ensues. The patients, when led to weep by their melancholy state, feel only a sensation of fullness in the eyes ; the tears do not come. Arlt found in a case of xerosis obliteration of the efferent ducts of the lachrymal gland pro- duced by the great shrinking of the conjunctiva, the lachrymal gland itself being diminished to one third of its normal volume and transformed into a tissue resembling fat. In that form of xerosis also which occurs in connection with keratomalacia there is a striking deficiency in the lachrymal secretion ; but here probably we have to do with a nervous disturbance, namely, with an ab- sence of the reflex lachrymal secretion, due to depression of the general nu- trition, and particularly of the nervous functions. In a case of this sort Cirin- cione has found on autopsy an inflammation of the ciliary ganglion and ganglion Gasseri. XII. Extravasation of Serum and Blood beneath the Conjunctiva. 25. OEdema and also extravasation of blood, if of any great extent, are observed only in the conjunctiva of the eyeball and in the retro- tarsal fold, as these, on account of the laxity with which they are fixed to the subjacent parts, can be readily lifted up over quite large areas by fluid. The same thing does not occur in the conjunctiva tarsi, be- cause it is too intimately adherent to the underlying cartilage. In the conjunctiva of the eyeball we meet with both inflammatory (Bdema (cedema calidum), occurring in inflammations of the eyeball or the organs near it, and with non-inflammatory redema (cedema frigi- dum), resulting from simple transudation of fluid. Since cedema, as a rule, is of importance merely as a symptom of some other affection, treatment will have to be directed to the latter. Should it be desirable to take any special measures against the cedema itself, the most suita- ble means for this purpose would be a pressure bandage, or, in the case of a tense oedema, scarification of the conjunctiva. DISEASES OF THE CONJUNCTIVA. 123 The exudation of blood beneath the conjunctiva of the eyeball is known as eccliymoma subco7ijunctivale. We then see a spot of varying extent and of a vivid-red or dark-red color ; sometimes the whole con- junctiva scleras is suffused with blood. Ecchymosis is easily distin- guished from an inflammatory redness of the conjunctiva by its uni- formly red coloration, in which no network of vessels can be recognized, and also by its sharp limitation from the unsuffused portions of the conjunctiva, which are ordinarily quite normal and uncolored. Ecchymoses of the conjunctiva develop after injuries and operations upon the conjunctiva (particularly after squint operations), and, fur- thermore, in violent inflanp^mations, especially in catarrhal ophthalmia. Spontaneous suffusions in an otherwise healthy conjunctiva are fre- quent in old people, whose blood-vessels have brittle walls, the rup- ture of the vessels being often occasioned by great bodily exertion, or by coughing, sneezing, vomiting, great straining, etc. In children also spontaneous ecchymoses of the conjunctiva are observed, chiefly after whooping-cough. A special symptomatic significance belongs to those ecchymoses which develop, to all appearance spontaneously, after an injury to the skull. Here we have to do with cases in which a fracture of the base of the skull has occurred, and the blood, as it escapes, gradually oozes forward through the orbit until it lodges beneath the conjunctiva (see § 133). Subconjunctival ecchymoses become absorbed in from a few days to a few weeks without producing any further serious consequences, and in themselves require no treatment whatever. We generally prescribe compresses of lead water, more for the purpose of appeasing the patient than of obtaining a more speedy resorption. Inflammatwy mdema is associated with the most various inflammatory affec- tions, such as inflammations of the lids (erysipelas, hordeolum), of the margin of the orbit (periostitis), of the lachrymal sac (dacryocystitis), of the conjunc- tiva (particularly acute blennorrhoea), of the eyeball itself (purulent keratitis, irido-cyclitis, purulent chorioiditis, and panophthalmitis), and, furthermore, of structures posterior to the eyeball (tenonitis, phlegmon of the orbit). Inflam- matory oedema, as also exudations of serum or of blood, is especially apt to occur in old people, whose conjunctiva is eminently extensible and so loosely attached that we observe oedema in this situation sometimes with trifling con- junctival catarrhs. We commonly find the oedema most pronounced in the region of the palpebral fissure, because here the counter-pressure exerted by the lids is wanting; and not infrequently an oedematous fold of conjunctiva is found in the palpebral fissure, pinched off, so to speak, from the rest by the lids. Non-mflammatory adema is caused by hydrsemia or by stasis. In the former case it occurs as a symptom of albuminuria, and sometimes then recurs a num- ber of times, but each time rapidly disappears again (oedema fugax). A pe- culiar sort of cedema is the filtration cedema of the conjunctiva of the eyeball. It is observed after operations or injuries which have produced a perforation in the most anterior sections of the sclera, and arises from the fact that the aqueous 124 DISEASES OF THE EYE. from the anterior chamber oozes between the incompletely closed edges of the wound and lodges under the conjunctiva. Accordingly, when cicatrization oc- curs, the oedema commonly disappears. But if a minute opening remains in the sclera, the cedema too persists — a condition w^hich is designated as cystoid cicatrization (see Fig. 65). CEdema from filtration is found either in the region of the fistulous opening or in the lower part of the bulbar conjunctiva, the fluid sinking in obedience to gravity. Not infrequently we see in the scleral conjunctiva small bright vesicles, arranged in a row like a string of pearls, or even joined so as to form longer sausage-like swellings. Here we have to do with dilated lymph vessels that are filled with a clear liquid — that is, with lympliatic ectasice. These occur both in inflammation of the conjunctiva and also when the conjunctiva is perfectly healthy. Mcchymoses of the conjunctiva, free from danger as they are, terrify the patient by their conspicuous look, especially if, as is frequently the case, they spread still further in the next few days after their first development. In these cases the Pinguecula stands out with peculiar distinctness, as a bright, white, or yellowish spot upon the red substratum. On the side of the trans- parent cornea the ecchymosis is limited by a narrow gray border. This is the inner margin of the limbus, which is too closely adherent to the cornea to be lifted up by the blood. In eyes with blue iris, the latter often has its color apparently changed to green in the spot corresponding to the ecchymosis. This is caused by the extension of the blood in a very thin layer (in which it appears green) between the lamellse of the cornea, so as to make the iris which lies be- hind it seem green. The entrance of air beneath the conjunctiva of the eyeball (emphysema) is sometimes observed simultaneously with the escape of air beneath the skin of the lids or into the orbital tissue (see § 114). XIII. TUMOES OF THE CONJUNCTIVA. 26. Both malignant and benign tumors occur in the conjunctiva. The most important form of benign tumors is the Dermoid Tumor.— This is a flat growth of solid consistence, which, so to speak, straddles the margin of the cornea, being situated partly in the conjunctiva, and partly in the cornea, with which latter it is immovably connected. It most frequently occurs on the external (tem- poral) side of the cornea (Fig. 34). Its color is white or reddish, its surface epidermoid and often dry. It is sometimes covered with fine down, or even with longer hair. Histological examination shows that the growth possesses the composition of the external skin ; it consists of a stroma of connective tissue, covered with epidermis, and contains hair follicles, sebaceous glands, and sweat glands. It is, so to speak, an island of skin upon the surface of the eyeball. Dermoid tumors are always congenital, and are frequently found along with other congenital anomalies, like congenital harelip or wart- like appendages of skin in front of the ears. Sometimes they grow still larger after birth. According to Eemak, their development, as in DISEASES OP THE CONJUNCTIVA. 125 the case of the allied dermoid cysts (see § 134), depends upon a foetal invagination of the external germ layer. On the other hand, Von Duyse conjectures that they owe their origin to a circumscribed ad- hesion between the amnion and the sur- face of the eyeball. The adhesion sub- sequently is drawn out into the form of a cord, and at length breaks quite in two, its point of attachment to the eye remain- ing behind as a dermoid tumor. The chief harm that dermoids do is to produce a considerable disfigurement. If they are large, and especially if they are covered with hair, they cause me- chanically an irritation of the eye, and also interfere with vision, in so far as tliey encroach upon the pupillary area of the cornea. They are removed by a simple process of ablation, which consists in separating the tumor as exactly as pos- sible from the subjacent cornea and sclera. The resulting wound in the cor- nea should, as far as possible, be covered by drawing the adjacent conjunctiva over it. That portion of the cornea upon which the tumor was formerly situated remains clouded permanently. If rem- nants of the tumor have been left, the latter may in part form again. Of malignant tumors, epithelioma and sarcoma of the conjunctiva occur. These originate ordinarily in the limbus conjunctiva, and thence extend both into the conjunctiva and into the cornea. Epithelioma of the conjunctiva forms a non-pigmented, flat, sessile tumor with a broad base. It remains for a long time confined to the superficial layers of the conjunctiva and cornea, its extension in the latter often resembling a pannus. The tumor shows a great tendency to superficial ulceration. The sarcomata that start from the limbus are generally pigmented (melano-sarcomata). In opposition to an epithelioma, they grow more in height than in breadth, and are attached to the substratum by only a slender base. They hence form dark-colored, very prominent mush- roomlike growths, which often overlie a great part of the cornea, although, if we lift them up, we find the cornea beneath for the most part normal. Both epitheliomata and sarcomata develop in advanced life, and, Fig. 34.— Dermoid Tumor of the Cor- nea AND Subconjunctival Lipoma IN A Thiktekn-year-old Girl. The dermoid tumor is situated on the outer and lower margin of the cor- nea, lying to a small extent in the cornea, and more largely in the sclera. The eye has to be turned strongly inward in oi'der to bj-ing the lipoma well into view. The lipo- ma has a form differing from the ordinary one in that it consists of two lobules, and in addition sends out a process reaching to the outer margin of the cornea. It is every- where covered by compact con- junctiva which resembles skin, but which nevertheless allows the yel- low color of the underlying fat to show through. 126 DISEASES OP THE EYE. if they are not removed, spread steadily ; sarcomata especially grow, until at length they form gigantic tumors. At last the patient suc- cumbs from exhaustion, or from metastases which form in the internal organs. The tumors must therefore be removed as early and as radically as possible. As long as they are still quite small and superficial radical removal can be performed with preservation of the eyeball. The tumor is removed as completely as possible, partly with the knife, partly with the sharp spoon, and the spot which it has occupied is thoroughly burnt with caustics, or, still better, with the actual cautery. If com- plete removal of the growth is no longer possible in this way, the eye, too, must be removed, even though it still possesses visual power. Of benign growths, the following, although of rare occurrence, are also ob- served : Lipoma subconjunctliiale forms a tumor, situated upon the upper and outer circumference of the eyeball, between the rectus externus and rectus superior muscle, and appearing of a yellowish color as seen through the conjunctiva. It is of triangular form, the sharply defined base of the triangle looking toward the cornea, while the two sides of the triangle, which are directed to the outer side, pass gradually into the orbital fat. If the tumor is small it ordinarily remains concealed beneath the outer canthus, and can be brought into view only by turning the eye strongly inward (Pig. 34). Larger lipomata are visible in the palpebral fissure even when the gaze is directed straight forward, and hence cause disfigurement; but they do no other harm. Microscopical examination shows that the tumor consists of fat lobules. The conjunctiva that coats it is thickened and of a character resembling skin, and in this regard a lipoma is akin to the dermoids (lipo-dermoid). Like the latter, it is congenital, but sometimes grows to a considerable size at the time of puberty. If it is desired to remove the tumor on account of the disfigurement it produces, we take away from it, after dividing the conjunctiva that covers it, as much of the mass of fat as is visible in the palpebral fissure ; a radical removal of all the adipose tissue is unnecessary. Cj/sts in the conjunctiva are commonly represented by small vesicles filled with a limpid liquid. Most of these vesicles, and particularly those situated upon the conjunctiva of the eyeball, originate from dilated lymph vessels (see page 134). In the retrotarsal fold cysts occur which take their starting point from Krause's glands, or from new-formed glands in the conjunctiva (page 43) ; and there are also cysts that are produced in the conjunctiva by traumatism. Larger cysts situated beneath the conjunctiva are formed by the cysticercus cellulosae. The latter is observed for the most part in children or in the young. In such a case the conjunctiva at one particular spot is found permeated with vessels, and forms a nodular protuberance. Underneath may be felt the cyst which, as a rule, can be readily pushed about upon the subjacent parts ; in indi- vidual cases, however, it is intimately adherent to the subjacent sclera or to one of the ocular muscles. If the cyst has very thin walls, the head of the worm can be recognized as a whitish spot in its interior. It is easy to remove the cysti- cercus by splitting up the conjunctiva and dissecting out the cyst, which con- sists of the cysticercus vesicle inclosed in a capsule of connective tissue that has been formed about the animal. DISEASES OP THE CONJUNCTIVA. 127 Under the name of polypi of the conjunctiva we understand soft, rarely rather hard, outgrowths attached to the conjunctiva by a pedicle, and having a smooth surface covered with mucous membrane. These originate most fre- quently in the retrotarsal fold or in the conjunctiva of the lids. As a rule, they are so small as not to be disclosed until the lids are everted ; sometimes, how- ever, they are large enough to project out between the lids. Larger polypi are frequently ulcerated upon their surface, as a result of the mechanical injuries to which they are necessarily subjected. In their nature polypi are small fibro- mata, which thrust the conjunctiva like a sac before them. Their treatment consists in ablation and a subsequent cauterization of their base with the silver- nitrate stick. Papillomata of the conjunctiva are frequently confounded with polypi, but are distinguished from them by their surface being not smooth, but papillary — that is, nodulated, like a raspberry or cauliflower. They are either provided with a pedicle or are sessile, having a broad base and extending in a flat layer over quite a large section of the conjunctiva. They start most frequently from the region of the caruncle, but can also take their origin from other portions of the conjunctiva, and sometimes several papillomata at once are present in dif- ferent portions of the conjunctiva. They must be removed very thoroughly, since they are extremely prone to recur. A third form of tumor, having an external resemblance to polypi of the conjunctiva, are the granulation tumors. These, like polypi, form small, mush- roomlike, pedicled tumors. Unlike polypi, however, they are not covered by conjunctiva, but consist of naked granulation tissue. They develop in places where a loss of substance exists in the conjunctiva, wliether as a result of ulcers (or even large efilorescences in cases of conjunctivitis eczematosa) or as a result of injuries or of operations (most frequently after tenotomies, at the site of the conjunctival wound, and, after enucleation, at the bottom of the conjunctival sac). In the case of chalazia, also, which have broken through the conjunctiva of the lids, we quite often see a granulation mass growing out of the opening. After existing for some time granulation tumors become more and more con- stricted at their base by the cicatricial contraction of the surrounding conjunc- tiva, so yaat they ultimately fall oS of themselves if they have not been previ- ously removed. The three varieties of tumors above mentioned often contain an abundance of dilated vessels; in fact, some cases of very vascular polypi have been de- scribed as pediculated angiomata of the conjunctiva. It is hence easy to con- ceive how these tumors can readily give rise to repeated hfemorrhages, especially if they are ulcerated in spots and are mechanically injured, as, for example, by the rubbing of the lids upon them. Many legends of tears of blood may be referred to this cause. Angiomata of the conjunctiva are, as a rule, those which were originally situated in the lids and have gradually passed over upon the conjunctiva. Pri- mary angiomata are of rare occurrence in the conjunctiva, and are generally found in the region of the inner angle of the eye. They are as a rule congenital, and increase in size after birth. With regard to their treatment, see Angiomata of the Lids (§ 115). As regards the malignant tumors, the epitheliomata and sarcomata, we must distinguish between those which originate in the surrounding structures, espe- cially the lids, and secondarily pass over upon the conjunctiva, and those which 128 DISEASES OP THE EYE. are from the beginning situated upon the conjunctiva and are hence to be looked upon as primary conjunctival tumors. These latter originate mostly from the limbus. The predilection shown by epitheliomata for the boundary line between the conjunctiva and cornea is to be considered as an analogue of the fact that, in other parts of the body also, epitheliomata occupy by prefer- ence those spots where one kind of epithelium passes into another, as, for instance, the boundary line between skin and mucous membrane (anus, lips, margins of the lids, etc.). An additional factor giving rise to the development of epitheliomata at the limbus is probably furnished by the peculiar disposition of the epithelium at this spot, for we find here sometimes, even in the healthy eye, a proliferation of epithelium, the latter growing in the form of conical processes into the depth of the tissue. Sarcomata of the conjunctiva are, as a rule, pigmented. In this respect they are distinguished from the epitheliomata, although, as an extreme rarity, cases of pigmented epitheliomata do occur. Melanotic sarcomata, as is known, de- velop in those localities in which pigment is already normally present. They hence occur upon the conjunctiva of the lids, and above all upon the limbus, two divisions of the conjunctiva, which even under physiological conditions contain pigment. At the limbus particularly the quantity of pigment con- tained is sometimes so considerable in persons of the brunette type that even with the naked eye we notice in it either discrete dark-brown spots or a more uniform brown coloration. Spots of pigment occur sometimes also in other por- tions of the conjunctiva, both of the eyeball and of the lids, and from these spots melanotic sarcomata may subsequently develop. It is impossible to make a radical removal of epibulbar epitheliomata and sarcomata and at the same time preserve the eye, in cases in which these tumors have so great an extent superficially that the conjunctiva has to be extensively sacrificed ; for in that case there would occur as a result of the operation so extensive a formation of cicatricial tissue, with consequent distortion and fixa- tion of the eyeball, that the latter would become unserviceable for purposes of vision, and it would have been better to extirpate it at the beginning. So, also, the eyeball must be sacrificed in those cases in which the tumor grows down into the depth of the tissues at any one point — a thing which is especially apt to happen along the anterior ciliary vessels. Such an occurrence is often not discovered until after the removal of the superficial growth, or may even not be discovered at all. In the latter case a recurrence in the same locality occurs soon after the apparently radical removal. The following history serves to show the malignancy of these tumors which in the beginning are of such in- significant minuteness: In the year 1879 a woman, fifty-seven years of age, appeared in the eye- clinic, at that time directed by Arlt, having a melano-sarcoma on the right eye- ball. This had developed from a minute red spot which had already existed for a series of years, and which had begun growing larger the year before. It had the dimensions of a large pea, was of reddish-brown color, and was situated in the conjunctiva on the outer side of the cornea. The base of the tumor pro- jected from the limbus somewhat into the cornea, but nevertheless did not ex- tend into the pupillary area, so that the visual power was perfectly normal. I extirpated the tumor by cutting through the conjunctiva at a certain distance from the edge of the tumor, and then removed the latter as carefully as jjossi- ble from its base. The wound surface thus formed, which lay for the most DISEASES OP THE CONJUNCTIVA. 129 part in the conjunctiva and to a smaller extent in the cornea, was scraped, and then the edges of the wound in the conjunctiva were united by a suture. Healing followed by first intention, and for a time the patient remained well. It was not till May, 1886— that is, seven years later — that the patient returned, having again an epibulbar melano-sarcoma on the right eye, which, however, this time was situated on the limbus at the inner side of the cornea, and formed a brown tumor half the size of a lentil. The thin cicatrix re- maining from the first tumor was still present, quite unchanged, at the outer margin of the cornea; the limbus at the upper and lower margins of the cornea also was quite normal. For this reason it was impossible to regard the melano- sarcoma, now situated at the inner corneal margin, as a recurrence of the tumor removed seven years before from the external corneal margin. In fact, it could only be referred to a disposition toward the formation of tumors, inherent in the limbus, so that after the removal of a tumor at one spot a similar one developed in another. (The same thing holds good for a case of epithelioma that I ob- served, which developed simultaneously and quite independently in both eyes, and in both at the inner margin of the cornea.) The small tumor was removed, and the place where it had been situated was superficially cauterized with the galvano-cautery loop. Recurrences, however, followed this extirpation in rapid succession. Four months later, in September, 1886, the woman returned with a recurrent growth at the upper corneal margin, and upon the removal of this, after another four months, two nodules formed in the conjunctiva to the inner and lower side of the corneal margin and at some distance from it. In order the more certainly to remove everything that was diseased, I resolved this time to enucleate the eye, although it was still serviceable for purposes of vision. In spite of this, a solid nodule made its appearance, not more than six months later, at the bottom of the orbit. The woman put ofl: having this removed, and did not come to the clinic until five months later. Meanwhile the glands in front of the ear, at the lower jaw, and on the anterior aspect of the neck had become enlarged and could be readily felt. Although now a radical oper- ation, consisting of a complete exenteration of the orbit and the removal of all discoverable glands, was performed, nevertheless only a few months afterward enlarged glands were again observed. Since then (in February, 1890) the woman has succumbed to an extension of the growth to the internal organs. Fibromata, osteomata (which are commonly congenital), myxomata, cylin- dromata, and lymphangiomata, although of very rare occurrence, should also be mentioned as tumors of the conjunctiva. The plica semilunaris and the caruncle which is situated upon it participate in the inflammations of the conjunctiva, so that it is unnecessary to treat of the disease of these parts separately. Sometimes the little hairs which the caruncle always has upon it are so long as to irritate the eye ; in that case the hairs must be epilated. The new formations of the caruncle are designated by the old name encanthis ; * benign new formations, such as simple polypoid or papillary outgrowths of the caruncle, are called encanthis benigna; malignant new for- mations are called encanthis maligna. * From iv, in, and Kovfliis, angle of the eye. CHAPTEE II. DISEASES OF THE CORNEA. Anatomy. 27. The cornea, together with the sclera, represents the outer fibrous envelope of the eyeball, of which the cornea forms the transparent por- tion. Seen from in front, the cornea has the form of a horizontal ellipse, the horizontal diameter of its base, which is twelve millimetres, surpassing the vertical diameter, which is eleven millimetres. It is thinner in the center than at the edges, where its thickness amounts to about one millimetre. Hence it follows that the curvature of the posterior surface is somewhat greater than that of the anterior. The latter has a radius of curvature of 7.5 millimetres. Since the radius of curvature of the whole eye is more than this — amounting, in fact, to twelve millimetres — the curvature of the cornea is greater than that of the rest of the eyeball ; the cornea therefore is placed like a watch crystal upon the sclera. The same comparison also obtains for the method in which the cornea is inserted into the sclera ; for, in its pos- terior layers the cornea extends farther toward the periphery than in the anterior, where the sclera, as it were, laps over the edge of the cornea (Fig. 23). The microscope, however, does not show any sharp boundary line between cornea and sclera ; on the contrary, the fibers of one pass continuously into those of the other. The healthy cornea is transparent. Almost all morbid changes of the corneal tissue make themselves known at once by a diminution of this transparency. In advanced age, however, a cloudiness makes its appearance even in the healthy cornea (arcus senilis corne® or geron- toxon*). This consists of a narrow gray line which runs near the cor- neal margin, and is concentric with it. It shows itself under the form of a gray arc, first at the upper, soon after at the lower, margin of the cornea ; finally the two arcs unite at the outer and inner side of the cornea to form a closed ring. The outer boundary of the arcus senilis is sharply defined, and is separated from the limbus by a strip of per- fectly clear cornea ; on its inner aspect, or the one turned toward the center of the cornea, on the other hand, the cloudiness gradually shades away until it is lost in the transparent cornea. * From yipav, an old man, and t((Jo(/, bow. 130 DISEASES OP THE CORNEA. 131 The cornea consists of the following layers : 1. The anterior epithelium (Fig. 35, E). This is a pavement epi- thelium consisting of several layers; the lowermost cells (foot cells, Fig. 29, «) are cylindrical, then follow rounded cells (Fig. 29, '/«), and finally flat cells (Fig. 39, o). . 3. Bowman's memlirane (lamina elastica anterior, Fig. 35, B). This is a thin, homo- geneous membrane intimately connected with the lamella of the cornea lying beneath it. It may be said to represent the uppermost layer of the stroma of the cornea, which has be- come homogeneous and desti- tute of cells. From the epi- thelium it is separated by a sharply defined border ; and, under pathological conditions as well as after death, the epi- thelium separates very readily from Bowman's membrane. 3. The stroma (Fig. 35, S). Til is is composed of a ground substance and of cells. The ground substance in its ulti- mate constitution consists of fine fibrillre of connective tis- sue, united by a cement sub- stance into flat bundles. The bundles are so applied to one another that lamella? (Fig. 35, /) are produced ; by the arrangement of these lamellffi in layers one above another, the cornea is built up. The latter has, therefore, a laminated structure. The individual lamella;, however, are not sharply separated from each other, but are connected by the interchange of bundles at frequent intervals. Hence, when we attempt to strip off the individual lamella; of the cornea, we find that this can not be done smoothly, but only with the simultaneous lacera- tion of the numerous connecting fibers. In many places between the individual bundles of the cornea, and also between the lamella; formed from the bundles, open spaces of greater or smaller size exist, which are filled with lymph and are hence called lymph spaces (seen in surface view in /, Fig. 36, and in Fig. 35. — Cross-section through a Normal Cornea. Magnified 100 x 1. i?, anterior epithelium ; i?. Bowman's membrane ; .S', stroma, composed of the corneal lamellae, ?, and the corneal corpuscles, K\ D. Descemet's membrane; e, posterior epithelium ; ji, nerves extending through Bowman's membrane and the epithelium. 132 DISEASES OF THE EYE. cross-section in K, Fig. 35). These are connected with one another by numerous minute canals (lymph canals, Fig. 36, C), and in this way constitute a continuous system of hollow passages, or system of lymph passages, permeating the cornea in every direction. This sys- tem is designed for the circulation of the lymph, and is of the greatest importance for the cornea, for, as the cornea does not possess any blood vessels, it is forced to depend for its nourishment solely upon its system of lymph passages. The cells of the stroma of the cornea, the corneal corpuscles, are contained in the spaces of the lymph system, and are of two kinds — non-motile and motile cells. The former are the fixed corpuscles of the cornea. They are cells with a large nucleus and a very flat, proto- plasmic cell body, and they lie in the lymph spaces, to whose ante- rior or posterior wall they attach themselves (P, Fig. 36). Proto- plasmic processes extend from their cell body into the lymph canals which start from the lymph spaces. These processes anasto- mose with the processes of neigh- boring fixed corneal corpuscles, so that in this way there is formed a system of connected protoplas- mic bodies (cells and their pro- cesses). We have thus in the cor- nea two connected systems — a positive one formed of protoplasm, and a negative one consisting of hollow passages (lymph spaces and lymph canals). The former system lies wholly within the latter, and, together with it, permeates the entire cornea. The protoplasmic system, however, nowhere com- pletely fills the cavity of the system of passages ; the space which is left unfilled is occupied by the circulating lymph. The second variety of cells belonging to the stroma are the motile corpuscles of the cornea (wandering cells), which were discovered by Kecklinghausen. These are nothing but white blood corpuscles which have made their way into the cornea, and which move about in its sys- tem of lymph passages. In the normal cornea they are present in very small amount ; but whenever any irritation acts upon the cornea they at once increase considerably in number, since they escape from the network of blood-vessels forming the marginal loops and pass into the cornea. These cells play an important part in inflammation of the cornea. Fig. 36. — Lamellae of the C ^rnea (Surface View). - (After Waldeyer.) In contrast with the ground substance, ff, which Is shaded in the drawing;, are the light-col- ored lymph spaces, 7, connected with each other by the lymph canals. C. Lying in the lymph spaces, without entirely filling them, are the protoplasmic bodies ( P) of the cor- neal corpuscles provided with the cell nu- cleus, K. DISEASES OP THE CORNEA. I33 4. Descemefs memirane {D, Fig. 35) is a homogeneous, hyaloid membrane whicli forms the posterior boundary of the cornea. Unlike Bowman's membrane, it is quite sharply separated from the stroma of the cornea, from which also it is chemically different. It is very re- sistant to chemical reagents, and likewise to pathological processes going on in the cornea. When the entire stroma of the cornea has already broken down into pus, we often see the thin Descemet's mem- brane still for days offering resistance and remaining unimpaired (see §33). 5. The posterior epithelium (endothelium, e. Fig. 35). This, under the form of a single layer of flattened cells, coats the posterior surface of Descemet's membrane. The cornea at its margin abuts against three membranes, the con- junctiva, the sclera, and the uvea (iris and ciliary body). Embryology teaches us that the cornea consists of three superimposed layers, each of which corresponds to one of the membranes adjacent, and may be said to represent its continuation over the most anterior portion of the eyeball. The cornea hence consists of three divisions — a conjunctival, a scleral, and a uveal. According to Schwalbe, the anterior epithelium forms the conjunctival portion of the cornea (the so-called conjunctiva cornese). Descemet's membrane, together with the posterior epithelium lining it, belongs to the uvea, while the entire stroma of the cornea, together with Bowman's membrane, represents the continuation of the sclera. In the fully developed eye these three divisions are fused into a common whole, although their community of origin with the adja- cent membranes still finds expression under pathological conditions; the conjunctival division suffering most of all in diseases of the con- junctiva, the uveal division in diseases of the uvea. The cornea contains no vessels. These cease at the margin of the cornea, forming there at the limbus the network of marginal loops, which is supplied by the anterior ciliary vessels (see page 41, and q, Fig. 22). From the marginal loops the blood plasma passes over into the system of lymph passages, by which the nutrition of the cornea is effected. The nerves of the cornea arise partly from the ciliary nerves, partly from the nerves of the bulbar conjunctiva. They are very numerous, particularly in the uppermost layers of the stroma, from which the nerve fibers pass forward through Bowman's membrane into the epi- thelium as far as the most anterior layers of the latter (Fig. 35, n). The cornea is therefore extremely sensitive to the touch. In the in- duction of narcosis the reflex that follows from touching the cornea (screwing together of the lids) is employed in order to test the depth of the narcosis, since this reflex is among those that are the last to disappear. Lesions of the cornea are particularly painful whenever they affect the uppermost layers which are so rich in nerves, as, for in- 134 DISEASES OP THE EYE. stance, in the case of exfoliation of the epithelium, by which the numer- ous fibers of the epithelial plexus of nerves are laid bare. While the cornea, viewed from in front, appears elliptical, it is circular, if looked at from behind. Hence the elliptical form of the front surface of the cornea is due to the fact that both sclera and conjunctiva overlap it farther above and below than at either side. There is not yet perfect unanimity of opinion as to the division of the cornea into three layers. Waldeyer liolds a different view from that represented in the text, regarding as the conjunctival portion the anterior epithelium, Bow- man's membrane, and the most anterior of the lamellae of the corneal stroma; the uveal portion would then be formed by the posterior epithelium, Descemet's membrane, and the most posterior of the lamellas of the corneal stroma, so that only the middle lamellae of the cornea would be left to form the scleral portion (cf. Fig. 89). The older authors ascribed an important part in the nutrition of the cornea to the aqueous humor, which was supposed to be constantly soaking through it, and thus supply it with nourishment and provide for the maintenance of its transparency. From experiments, performed especially by Leber, this view must be considerably modified. An exchange of fluid between the parenchyma of the cornea and the aqueous humor is conceivable as occuri-ing in two ways : by diffusion, which takes place only by means of diosmosis, and by the more rapid process of filtration, in which the fluid passes through comparatively large gaps in the tissue. The first sort of interchange — that, namely, by diffusion — is the only one that takes place in the healthy cornea; and the aqueous humor which gets into the cornea in this way may contribute to the nutrition of its posterior layers. Diffusion may also occur in the reverse direction— that is, from before backward. If, for instance, a solution of atropine is dropped upon the cornea, atropine is found a short time afterward in the aqueous humor. But interchange of fluids by flltration does not occur in the normal cornea. Leber has shown that it is the posterior epithelium which opposes the filtration of fluids. If this is removed, the aqueous humor penetrates in considerable quantity into the cornea, which in consequence becomes cloudy and swollen. Clinical Examination of the Cornea. 28. An examination of the cornea must have regard to the follow- ing points : 1. The size and form of the cornea. Both may be altered either in consequence of congenital defects or because of morbid processes. Overlapping of the cornea by the limbus to an unusual extent, or the presence of marginal opacities in the cornea, not infrequently simulates a diminution in size or an irregularity of form. 3. The surface of the cornea must be examined with regard to its curvature, its evenness, and its polish. In respect to (a) the curvature of the cornea as a whole, marked anomalies are recognizable at the first glance ; slighter changes, however, require more precise examination by means of the reflex images (see page 2). The cornea acts as a convex mirror, the greater the curvature of which the smaller is the reflected DISEASES OP THE CORNEA. 135 .-J ^ ®' «A 6' image. In order to be able to Judge whether the reflex image given by a particular cornea is of abnormal dimensions, we must compare it with the image reflected from another cornea which is healthy, and most conveniently with that from the cornea of the other eye, in case it is normal. The diagnosis is easy when the curvature varies at differ- ent portions of the same cornea (as, for instance, in keratoconus, in which the central portions have a greater curvature than those at the periph- ery). In such a case we cause the eye to move about in such a way that the reflection of a window op- posite falls successively upon differ- ent portions of the cornea, and then we see the reflex image becoming larger or smaller according to the varying curvature of the cornea. The evenness (b) of the corneal sur- face, together with the perfection of its polish, gives to the normal cor- nea its brilliant luster. Here again the reflex images afford the best means of testing both of these prop- erties. These images lose their reg- ularity of form at the place where the cornea is uneven ; they appear distorted, owing to their outlines being irregularly bowed in or out. The form and extent of the in- equality may be deduced from the kind of distortion of the reflex image. By the ophthalmoscope, too, we can recognize inequalities of the corneal surface, on account of the irregular astigmatism which they produce (page 18). The uneven spots upon the corneal surface are either depressions (losses of substance) or elevations. Furthermore, the cornea may be uneven from being wrinkled (rhytidosis* corneas) or from being entirely collapsed (collapsus cornese). Both of these conditions occur in cases of great diminution in the tension of the e3'e- ball, hence particularly after the escape of the aqueous or vitreous humors. If (c) the polish of the cornea is entirely lost, the latter Fig. 37.— Corneal Epithelium in a Case op Increase of Tension. Magnified 500 x 1. The specimen was from a case in which in- crease of tension set in after iridocyclitis. C, parenchyma of the cornea with the flat nuclei of the corneal corpuscles. B, Bowman's membrane, through which in two places fine nerve filaments are seen passing. At the anterior ends of these nerve filaments and also at other spots there are seen between the bases of the lowermost cylindrical cells (foot celis) light-colored rounded spaces, which rep- resent very minute droplets of liquid. The lines of division between the foot cells are in general represented by lighter col- ored lines, which indicate that the cells are to a certain extent pressed apart by fluid and their interconnections broken up. On the other hand, the cells of the middle layer are bordered by broad, dark lines corresponding to the interlocking teeth of these, the pectinate cells. In the uppermost layers there are numerous cells altered by imbibition of fluid. In the cell a this fluid occupies the greater part of the cell body, so that the cell itself is enlarged. At b the anterior wall of a cell that was filled with fluid has fallen off. At c t'le liquefied contents of a cell have been evacuated through a slender open- ing. Owing to these changes in the up- pcimost cells, the surface of the epithe- luim as a whole is uneven. * From pvrisy a wrinkle. 136 DISEASES OP THE EYE. becomes lusterless (dull) ; it looks like glass that has been breathed upon, or looks as if it had been smeared with grease. The reflex images show their normal size and form, but have lost their sharp outline. Lack of luster of the cornea is also caused by the. presence of inequali- ties so minute as to be nearly or quite imperceptible to the naked eye. Such inequalities may consist either of elevations or depressions. The latter are produced by the detachment of isolated epithelial cells in a number of places, thus leaving minute excavations (Fig. 37, b) ; the surface of the cornea looks as if stippled by needle pricks. In other cases we see the roughness of the cornea produced in the opposite way — that is, by its surface being covered with numerous small elevations, in which case the cornea looks as if it were made of shagreen. Here we have to do with multiple elevations, produced by a lifting up of the epithelium, and occurring under the form of minute vesicles. .3. The transparency of the cornea is a property which belongs to its parenchyma, not its surface ; which latter, in fact, is only a mathe- matical concept, an expression for the superficial space bounding the cornea and lying between it and the air. Dense opacities of the cornea are visible from a distance ; but for the recognition of slight opacities, lateral illumination, and often also the use of the magnifying glass, are indispensable. By means of these aids to diagnosis we determine the form, extent, and denseness of the opacity. We make out whether it is found in the superficial or in the deep layers of the cornea, and further whether it is diffuse or is com- posed of separate small points, spots, or strife. Many an opacity which appears diffuse when seen with the naked eye proves, when looked at with the magnifying glass, to be compounded of smaller opacities. Such an opacity may subsequently become really homogeneous by the enlargement and confluence of its components. 4. The sensitiveness of the cornea is tested by touching it with the end of a thread or a shred of paper. In many diseases the sensitiveness of the cornea is diminished, or is abolished altogether. I. Inflammation- of the Coknea. General Statement. 29. In the course of an inflammation of the cornea (keratitis *) we observe the following stages. The inflammation begins with an infil- trate (Fig. 38). Cells in increased number make their appearance within the parenchyma of the cornea, and these constitute the exudate. As a consequence of this the diseased part loses its transparency. The level of the cornea remains normal at this spot, only the epithelium suffers to the extent of losing its polish, so that this portion of the cor- * From Kepas, horn. DISEASES OF THE CORNEA. 137 FlQ, ■Infiltrate in the Cohnea. (After Saemisch.) The epithelium, e, and Bowman^s membrane, b, over the infiltrate are preserved. nea appears dull upon the surface. The clinical signs of the existence of an infiltrate hence are cloudiness of the cornea, and loss of luster over the clouded portion, but no unevenness of the surface. The subsequent fate of the infiltrate varies. It may go on to resorption or to suppuration. (a) Resorption occurs in those cases in which the accumulation of exudate between the lamellae of the cornea is not excessive, so that the lamellae of the cor- nea are not broken down by reason of its presence, and hence there is nowhere produced any destruction of the tissue of the cornea itself. In this case the resorption of the exudate represents the second or regressive stage of the inflammation, and with it the morbid process comes to a conclusion. In favorable cases, when the cells constituting the exudate have disappeared by resorption, the dis- eased spots may become perfectly normal once more and regain their transparency (healing without permanent sequelae — i. e., without opaci- ties). But it may also hap- pen that the stroma of the cornea may not be abso- lutely destroyed by the deposition of the exudate, and may yet have experi- enced such an alteration of its structure that, even after the disappearance of the exudate, it never again becomes perfectly transpa- rent. Or it may be that the exudate deposited be- tween the lamellae of the cornea does not disappear completely by resorption, but in part becomes organ- ized and is left permanently fixed in the cornea. In both of these cases the infiltrate disappears by a process of healing, but leaves a permanent opacity behind. All those cases in which resorption of the exudate oc- curs without breaking down of the corneal stroma are grouped together under the common name of nonsuppurative keratitis. Fig. 39.— Corneal Ulcer in the PRoaRESSrvE Stage. (After Saemisch.) The base of the ulcer is formed by an accumulation of pus cells, which also push their way some distance in between the lamella of the cornea that adjoin the ulcer. At the edges of the ulcer, which are somewhat raised, the epithehum, e, and Bowman's membrane, 6, end as if cut short off. 138 DISEASES OP THE EYE. (b) The infiltration goes on to siippuration, when the exudation is such as to be no longer compatible with the maintenance of life by the corneal stroma, so that the latter breaks down. The inflammation then enters upon its second stage, that of suppuration, which is associated with a localized destruction of the cornea. These cases of keratitis are known as suppurative keratitis. The most frequent form of suppurative keratitis is the corneal ulcer in which the process of purulent disintegration begins in the most anterior layers of the cornea (Pig. 39). In this way a superficial loss of substance is produced which is recognizable as a depression in the corneal surface. In the beginning, the loss of substance repre- sents only those parts which are most mark- edly infiltrated, and hence are the first to break down. Sur- rounding these are lay- ers, which likewise are infiltrated with the ex- udate, although not to as high a degree. Hence both the floor and the walls of the ulcer are still infiltrated, for which reason we call it a foul (coated, infiltrated, or progressive) ulcer. Later on the infiltrated portions forming tlie floor and the wall of the ulcer, so far as they are incapable of living, are also cast off ; but those parts of the corneal tissue which have retained their ability to live remain, are freed by a process of resorption from the exudate which infiltrates them, and become once more transparent. The ulcer has, it is true, become somewhat larger than before, but the cloudiness surrounding it has disappeared ; the ulcer has acquired a smooth, transparent base and edges ; it is a cleansed {regressive) ulcer (Fig. 40). ' Among the clinical signs by which we diagnosticate an ulcer, the most important is the unevenness of the corneal surface, the latter presenting a depression or loss of substance. In foul ulcers this de- pression is surrounded by clouded corneal tissue, which, moreover, is dull upon its surface ; the floor of the ulcer also is gray and uneven. In clean ulcers the cloudiness surrounding them is very slight, or is want- ing altogether, and the floor and edges of the loss of substance are smooth and shining; the ulcer gives a mirrorlike reflex. Fig. 40. — Corneal Ulcer in the Regressive Stage. (After Saemisch.) The base of t]ie ulcer is formed by the denuded lamellse of the cornea ; a sli2:ht increase in the number of cells between them can still be made out. At the edges {b) of the ulcer the epithelium, e, is beginning to grow out over the base. Newly formed blood-vessels (g), lying in the upper layers of the cornea, run to the ulcer. DISEASES OP THE CORNEA. 139 Fig. 41.— Cicatrix of the Cornea. (After Saemisch.) The epithelium, e, is everywhere present, but over the cica- trix it is irregular, and in places (at a) is thickened. Bow- man's membrane. 6, is wanting at the site of the cicatrix. The latter itself is distinguished from the tissue of the normal cornea by its denser and less regular texture. Every keratitis suppurativa entails a loss of substance in the cornea. This must be filled up again by newly formed tissue, in doing which the process enters upon its third stage — that of ^ cicatrization. The new- ly formed tissue is not corneal tissue, but con- nective tissue, and is ac- cordingly opaque (Fig. 41). Hence suppurative keratitis always leaves a permanent opacity after it. The opacity, indeed, is the principal clinical sign of a cicatrix, for the corneal surface has completely reacquired its luster, because its epithelium is restored to the normal state, and the excavation or loss of substance has disap- peared, at most a slight flattening of the surface being present. Kecapitulation. — As has been stated above, non-suppurative kerati- tis has two stages, the stage of infiltration and that of resorjDtion. In suppurative keratitis, on the other hand, we distinguish three stages : the stage of infiltration, the stage of suppuration, and the stage of cicatrization (reparation). The stage of suppuration is composed of two periods, the progressive period (foul ulcer) and the regressive pe- riod (clean ulcer). In the clinical diagnosis of the form and the stage of an inflamma- tion of the cornea we proceed in the following manner : We first ex- amine the corneal reflex. If the surface is dull, we are dealing with a recent affection, and in that case, if there is no loss of substance, with an infiltrate; hut if a loss of substance is present, with a foul ulcer. If the surface is lustrous, the affectioti is an old one, and, if a loss of substance is present, is a clean ulcer ; but if no loss of substance is visible, we are dealing luith a cicatrix. 30. Vascularization of the Cornea. — In inflammations of the cornea we very frequently observe the development of vessels which grow in upon the cornea from its margin. This occurs most frequently during i\\& 2:irocess of healing of corneal ulcers. At the time when the ulcer begins to become clean, we see vessels starting out from that part of the limbus lying next to the ulcer. These vessels lie in the most su- perficial layers of the cornea and extend toward th« ulcer, whose edges they soon reach (Fig. 40, g). Their chief office seems to consist in supplying the necessary material for filling in the loss of substance. 140 DISEASES OF THE EYE. Their ad rent is therefore to be regarded as a favorable occurreuce ; we know that at the spot where the vessels have reached the ulcer the further progress of the latter is ao longer to be apprehended — that, on the contrary, it will there enter upon the process of healing. After the loss of substance has been filled in the vessels gradually disappear, so that a corneal cicatrix contains fewer and fewer of them as it be- comes older. Nevertheless, the blood-vessels never entirely disappear from the large cicatrices. In other cases the formation of new vessels accompanies the prog- ress of the inflammatory process, and hence belongs, like the exuda- tion itself, to the clinical picture of the inflammation. The best exam- ple of this is afforded by the vascular form of parenchymatous keratitis (§ 41)- A kind of vascularization differing from both of these varieties is that which forms one of the symptoms of panniis. Here the vessels do not lie in the cornea itself, but in a newly formed tissue which is deposited upon the cornea and of which they form an essential constit- uent (Fig. 27). It is very important to determine the situation of the vessels in the cornea — that is, whether superficial or deep — since by this fact alone we can often diagnosticate what sort of keratitis we are confronted with. The type of superficial vascularization is afforded by paunus, that of deep vascularization by keratitis parenchymatosa. The signs which enable us to distinguish the two kinds of vasculari- zation from each other may be contrasted as follows : SuPEEFioiAL Vessels Deeply situated Vessels (Fig. 42) (Pigs. 43, 44) spring from the network of mar- spring from the vessels of the ginal loops of the. limbus, andean sclera close to the margin of the therefore be followed from the cor- cornea, and hence appear to come nea into the limbus, and thence on to an end suddenly at the limbus, to the vessels of the conjunctiva. as they disappear behind the latter to enter the sclera. On account of their superficial Are not distinctly recognizable, position are clearly visible and well- or are even unrecognizable, except defined, and have a vivid-red color, as a diffuse red coloration, and have a dirty-red (grayish-red) hue ; the reason for both of these appear- ances being that the vessels are veiled by the clouded layers of cor- nea lying in front of them. The vessels branch in an arbo- The vessels form fine twigs rescent fashion. which run parallel to each other (besom form of branching). DISEASES OF THE CORNEA. 141 The surface of the cornea is uneven, from the fact that the ves- sels raise up the epithelium that lies directly over them. The surface of the cornea is lusterless, it is true, but not un- even. Fig. 42.— Supekficial Blood- vessels IN Pannus. Mag- nified 8x1. Fig. 43.— Dkep-ltinq Blood- vessels IN Parenchyma- tous Keratitis. Magnified 3x1. Recent case with penicillate branching. Fig. 44.— Deep-lying Blood- vessels IN Parenchyma- tous Keratitis. Magni'fied 2x1. Old case with besora- like branching of vessels. Participation of Neighboring Organs in the Process. — Every kera- titis is accompanied by inflammatory symptoms, the most important of which is — ■ (a) The injection of the blood-vessels. The characteristic mark of corneal inflammation is ciliary injection. When the inflammation is great, conjunctival injection also makes its appearance, and may con- ceal the ciliary injection to a greater or less extent. Very violent sup- purative inflammations of the cornea are accompanied by cedematous swelling of the conjunctiva and even of the lids. {b) The iris and even the ciliary body become inflamed in cases of marked keratitis, so that we see the symptoms of iritis and iridocyclitis set in (see §§ 67 and 68). These accompanying inflammations may be intense enough to bring about the destruction of the eye. (c) Hypopyon * is the accumulation of a purulent exudate at the bottom of the anterior chamber. It forms a frequent symptom in keratitis suppurativa. We then find collected in the lowest portion of the chamber a yellow mass which, because it is fluid, is limited above by a horizontal line, and for the same reason is seen to change its place and seek the deeper portions of the chamber when the head is moved. In other cases the mass is viscid or pultaceous, so that when seen from in front it has a border that is convex upward, or it lies quite like a solid ball at the bottom of the chamber and does not change its position with the movements of the head. The quantity of the pus produced in this way varies greatly, ranging from a scarcely perceptible crescent lodged in the lowest sinus of the chamber up to masses of such size that the entire chamber is filled by the hypopyon. Hypopyon may * From vir6, beneath, and viov, pus. 142 DISEASES OF THE EYE. disappear by resorption, this process taking place the more rapidly the more fluid the hypopyon is. Pretty thick masses of exudation may become organized and lead to occlusion of the pupil, or, in rare cases, to adhesion of the iris to the posterior surface of the cornea. (d) The subjective phenomena associated with keratitis are pain and photophobia, together with the lachrymation and blepharospasm which these conditions cause, and also disturbance of vision — symp- toms which are met with in very varying degree. The Mstological processes occurring in inflammation of the cornea have been the subject of the most zealous investigations, and especially of investigations experimentally conducted, because the attempt was made to study in this field the problem of inflammation in general. For such studies the cornea is par- ticularly adapted on account of its transparency, and also on account of the characteristic form of the fixed elements of its tissue. There is no doubt that in every keratitis there occurs an increase in the number of the cellular elements, whose accumulation causes the cloudiness of the cornea, visible to the naked eye, and finally, if very considerable, terminates in the formation of pus. Never- theless observers could not agree as to the source of the new cells which made their appearance in the cornea. Some, the leader of whom was Cohnheim, look upon them as white blood corpuscles which have migrated into the cornea from the vessels of the corneal margin. Others, and especially Strieker, con- sider them derived from an increase in number of the normal fixed cells of the cornea. It is certain that both processes occur, although a different significance attaches to the two. Whenever an irritant productive of inflammation affects the cornea numerous white blood corpuscles wander into the latter. These are derived from two sources: In part they originate from the conjunctival sac, getting from there into the affected region of the cornea, because the epi- thelium here is lacking; in part they arise from the vessels of the corneal mar- gin, from which they make their way between the lamellse of the cornea until they reach the inflamed spot. The cells derived from the corneal margin in certain cases form a ring-shaped infiltration (invasion ring) about the diseased area, giving to the latter, especially in the case of ulcus serpens, a characteristic appearance. The white blood corpuscles that have emigrated from the net- work of marginal vessels into the cornea form the main mass of the exudate. On the other hand, the fixed corneal corpuscles, while taking but an insignifi- cant part in the formation of the exudate, do produce by their proliferation most of the material for the reparative process, that follows the inflammation, and which results in the development of new tissue. In the healing of the losses of substance produced by inflammation, the re- generation of the epithelium and the regeneration of the stroma of the cornea require separate consideration. The epithelium of the cornea is replaced by the growth of the epithelium from the edge of the ulcer. Losses of substances which affect the epithelium only, heal with a perfect restoration to the normal state and without leaving a permanent opacity. On the other hand, every loss of substance of the corneal stroma is filled up by cicatricial tissue which forms from the bottom and sides of the ulcer. The chief part in this is taken by the fixed cells of the cornea in the immediate neighborhood of the ulcer as these increase by division, and the cells which thus arise grow into connective-tissue DISEASES OF THE CORNEA. I43 fibers. The tissue thus formed is, however, essentially different from the normal tissue of the cornea (Fig. 42). The regular arrangement of the normal fibers of the cornea is wanting, and so, too, are the stellately branched fixed corneal corpuscles, which are replaced by ordinary connective-tissue cells. Bowman's membrane (Fig. 41, b) is never regenerated. The epithelium (Fig. 41, e) hence lies directly upon the cicatricial tissue, from which, being thinner in some places and thicker in others, it is separated by an irregular line. As a consequence of these peculiarities, the cicatricial tissue never possesses the perfect transparency of the normal cornea, and is hence recognizable even with the naked eye as an opacity. After having existed for a long time, the texture of the cicatricial tissue approximates somewhat more closely to the regular structure of the corneal tissue. It accordingly gains in transparency, and a " clearing up " of the opacity is observed to take place — a process, how- ever, which never gets to the point of producing a complete disappearance of the opacity except in the case of quite small and superficial cicatrices. In deep losses of substance the restoration of the normal epithelial coating does not delay making its appearance until the ulcer itself has been completely filled up by cicatricial tissue. On the contrary, from the moment when the ulcer has become clean the epithelium begins to grow over the latter, and hence begins to cover it at a time when there is no cicatricial tissue jiresent, or only a very thin layer of it (Fig. 40, at 6). At this time the ulcer (on account of the absence of opaque cicatricial tissue) is still almost completely transparent, and, as a consequence of the restoration of the epithelial covering, is smooth and shining. The formation of cicatricial tissue now goes on beneath the epi- thelium, and by this process the latter is gradually lifted up to its normal level. In proportion as the layer of cicatricial tissue becomes thicker, the degree of opacity naturally increases ; but it would be a very great mistake for the physi- cian to conclude from this fact that the disease was advancing. The signs before given, having regard to changes in the luster, evenness of surface, and transparency of the cornea, serve for the diagnosis of the variety of corneal disease that is present. They are not always, to be sure, found com- bined in a manner as schematic as has been represented. Some examples may show in what way exceptions to them occur. The opacities that are present upon the cornea may be old, and yet the cornea, because of a coincident in- crease of tension, may look dull and stippled. The surface of the cornea is not always smooth when there are infiltrates, nor yet when there are cicatrices. In the case of infiltrates, a bulging forward of the surface of the cornea often takes place on account of the deposition of an excessive quantity of exudation ; in the cases of cicatrices, on the other hand, a flattening may take place in consequence of an insuflicient filling in of the loss of substance. In doubtful cases, we must take still other factors into consideration, which may furnish points that will establish our diagnosis. Thus, in the case of a cicatrix, the outline of the opacity is commonly better defined than in the case of a recent opacity due to inflammation. The color of the latter form of opacity varies from gray to yel- lowish white and to yellow; cicatrices, on the contrary, present rather a pure white, or, if thin, a bluish-white hue. Recent inflammatory processes are asso- ciated with attendant inflammatory symptoms (ciliary injection, etc.), which are wanting in the case of cicatrices. By putting all these facts together the right diagnosis can almost always be made. Fluorescin is used to make more apparent those spots upon the cornea that 144 DISEASES OP THE EYE. are destitute of epithelial covering (erosions and ulcers). If a one-per-cent so- lution of potassium fluorescin is instilled into the conjunctival sac, and then ■washed out again with water, the highly fluorescent liquid penetrates solely into those portions of the cornea that are unprotected by epithelium, and such portions consequently are stained a vivid green. I use this method in clinical instruction to make small losses of epithelium more plainly visible ; but for the actual diagnosis of defects of the sort it is not necessary. The exudation into the anterior chamber, which accompanies every well- marked keratitis, depends upon the fact that irritant substances from the in- flamed cornea diffuse into the aqueous and then act upon the vessels of the uvea (i. e., the iris and ciliary body). As the first result of this, the aqueous, which under normal conditions contains only a trace of albumin, gets to con- tain such an amount of it that a layer of fibrin is precipitated upon the poste- rior surface of the cornea and often also upon the anterior surface of the iris (Figs. 90 and 99). In such cases the cornea, in addition to the circumscribed opacity that corresponds to the area diseased, presents over its entire extent a delicate diffused cloudiness produced by the layer of exudate upon its posterior surface. When the irritating substances produced by the inflammation are such as to excite a moi-e intense action, leucocytes pass out in considerable quantities from the vessels of the iris and ciliary body, and cause a cloudiness of the aque- ous, in which they become suspended. Later, by sinking to the bottom of the anterior chamber these cells form the hypopyon. The latter, therefore, origi- nates not from the cornea, but from the vessels of the uvea, as, indeed, is also apparent from the fact that many of the pus corpuscles contain pigment gran- ules, which they have transported with them from the inflamed uvea. Since the hypopyon has this origin, we understand why it is found to be free from pus cocci. It is owing to this freedom from germs that the hypo- pyon is tolerated by the tissues bordering the anterior chamber, and produces no special reaction in them. If ordinary pus containing cocci is injected into the anterior chamber of a rabbit, the eye is rapidly destroyed by panophthalmitis. But the pus that constitutes a hypopyon is not only tolerated by the eye with impunity, but can even undergo absorption without leaving any injurious effects behind. The resorption of the hypopyon takes place chiefly through the meshwork of the ligamentum pectinatum (§ 60). The rapidity with which absorption pro- ceeds varies exceedingly. In many cases a hypopyon of considerable size dis- appears so completely that after twenty-four hours scarcely a trace of it is to be found ; in other cases the hypopyon remains lying at the bottom of the cham- ber so long that it becomes organized. Sometimes we observe a rapid alterna- tion in the height of the hypopyon which at times decreases, and again increases once more. Subdivision of Keratitis. 31. The subdivision of keratitis into keratitis suppurativa and kera- titis non-suppurativa corresponds most fully to practical requirements. Every suppurative keratitis, since it is associated with destruction of corneal tissue, leaves behind it a permanent opacity, which in many cases injuriously affects the visual power. On the contrary, so long as purulent dissolution of the cornea has not taken place — that is, in non- DISEASES OF THE CORNEA. 145 suppurative keratitis — a complete restoration of its transparency, and with it of the normal power of vision, is possible, and, in fact, often does take place. Moreover, the above subdivision also corresponds to the essential characters of the corneal inflammations. For it is not merely a matter of accident whether an infiltrate in the cornea goes on to suppuration or to resorption. On the contrary, the forms which tend to the production of suppuration ordinarily present from the very be- ginning characters differing from those borne by forms in which there is no progress toward suppuration, so that these two categories are dis- tinct not only in their consequences but also in their clinical aspect. To each of the two categories a number of different forms belong, the most important of which are set forth in the following list : A. Keratitis Suppurativa. 1. Ulcer of the cornea. 3. Ulcus serpens cornese. 3. Keratitis e lagophthalmo. 4. Keratoma] acia. 5. Keratitis neuroparalytica. B. Keratitis Non- Suppurativa, {a) Superficial forms. 1. Pannus. 2. Keratitis with the formation of vesicles. {I) Deep forms. 3. Parenchymatous keratitis. 4. Deep keratitis. 5. Sclerosing keratitis. 6. Keratitis starting from the posterior surface of the cornea. A. SuPFUBATivE Keratitis. 1. Ulcer of the Cornea. 32. Symptoms and Course.— Every ulcer of the cornea develops from a superficially disposed infiltrate. In the beginning we find one spot upon the cornea cloudy and the surfcce over it dull (infiltrate). Then the epithelium exfoliates upon the surface of the affected spot, and soon, by the breaking down of the most strongly infiltrated por- tions of the cornea, a loss of substance forms in the parenchyma of the cornea, so that an ulcer is produced. This is at first surrounded by infiltrated portions of the cornea— a fact which we recognize by the base of the ulcer being gray and uneven, and its walls likewise gray and clouded. The walls of the ulcer are often surrounded for quite a dis- tance by a gray area, or slender gray striae, extending from the ulcer in 10 146 DISEASES OF THE EYE. different directions into the transparent cornea. This is an unclean or progressive ulcer (Fig. 39). In a favorable case, only so much of the cor- neal tissue breaks down during the further progress of the disease as was from the very beginning too strongly infiltrated to live. In this case the ulcer rapidly becomes clean without attaining great dimensions. But it very often happens that, simultaneously with the breaking down of the parts that are most strongly infiltrated, the inflammatory cloudiness keeps spreading, new portions of the cornea being constantly attacked by the infiltration. And since these, too, break down into pus, the ulcer grows constantly larger. This progressive growth of the ulcer takes place sometimes more in the direction of its depth, sometimes more along the surface. In the former case, perforation of the cornea is to be apprehended; in the second case, larger and larger areas of the cornea may be destroyed and thus extensive opacities be produced. Progressive growth along the surface often takes place chiefly in one direction — a fact which can be easily recognized by a particularly marked gray cloudiness, or even a yellow cloudiness, of the ulcer wall on the corresponding side. It may even happen that the ulcer keeps constantly advancing in one direction, while on the opposite side it heals just as fast, so that it goes creeping over the cornea {serpigi- nous * ulcer). The progressive stage of the ulcer is accompanied by symptoms of irritation like ciliary injection, lachrymation, photophobia, and pain, which not infrequently reach a considerable height ; moreover, in this stage hypereemia and even inflammation of the iris make their appear- ance (evidenced by turbidity of the aqueous humor, hypopyon, dis- coloration of the iris, contraction of the pupil, posterior .synechia). There are, however, cases of ulceration in which the irritative symp- toms are very slight, or are wanting altogether — cases constituting what are called torpid or asthenic ulcers — which nevertheless may be very dangerous. When the infiltration has finally come to a standstill, the ulcer enters upon its regressive stage. The tissue that has been destroyed is cast ofl', that which has not been destroyed becomes transparent once more from resorption of the exudate. The ulcer "cleanses" itself (Fig. 40). A clean ulcer presents a smooth base and edges with little or no opacity, and is chiefly to be diagnosticated by the excavation of the surface of the cornea, which we recognize when examining the cor- neal reflex. In proportion as the ulcer becomes clean, the associated symptoms of irritation disappear. After the ulcer has become entirely clean, cicatrization begins. Vessels extend from the nearest portions of the limbus to the ulcer, which latter, in cousequenco of becoming filled with the. opaque mass * Prom serpere, to creep. DISEASES OP THE CORNEA. 147 of the cicatrix, becomes again more clouded, but at the same time con- stantly shallower, until finally it reaches the level of the adjacent nor- mal cornea. Not infrequently, however, the new formation of the cica- tricial mass comes to a standstill before the loss of substance has been quite filled up, so that the surface of the cicatrix remains permanently a little sunken. When such cicatrices are small they are, on account of the thinness of the cicatricial tissue, almost or quite transparent, and disclose their presence by a flattening of the cornea {corneal facet), only discernible upon examination of the corneal reflex. On the other hand, cicatrices not infrequently occur which project above the level of the surrounding cornea. Such are the cases in which the cornea at the Fig, Keratectasia produced by an Ulcer. Magnified 25 x 1. The thinned and protruding cicatrix is distingui.shed by its denser texture from the adjacent normal cornea. The epitheUum, *', over it is thickeiied, while Bowman's membrane. 6, is wanting. On the other hand, Descemet's membrane, d, with its epithelium, is everywhere present— a proof that the ulcer has not perforated. base of the ulcer, having become thinned, does not offer resistance to the intra-ocular pressure, and bulges forward. The bulging may disap- pear, owing to the contraction of the cicatricial tissue; but it may also remain permanently {ectactic cicatrix, keratectasia* ex ulcere. Fig. 45). The formation of ectactic cicatrices is, however, of much more frequent occurrence after perforation of the cornea. 33. Perforation of the Cornea. — The course which an ulcer takes is much more complicated when the latter perforates the cornea. Per- foration takes place when the ulcer has penetrated down to the deepest layers of the cornea. The patient suddenly experiences violent pain, and feels a hot liquid (the aqueous humor) gushing out of the eye, after which, not infrequently, the severe pains previously existing sub- side. Perforation may occur spontaneously or in consequence of a sudden increase of the intra-ocular pressure, such as may be caused by bodily exertion (even, for example, stooping), or by coughing, sneezing, screwing together the lids, crying (in children), etc. The increase in intra-ocular pressure, which develops under these circumstances, is to be referred to two causes : it is partly a result of the increase of blood * From Ke'pos, horn, and cktoo-is, distention, from iRTiiveiv, to stretch out. 148 DISEASES OF THE BYE. pressure (from the straining of the muscles, and also from congestion in the district drained by the superior vena cava), partly produced by direct compression of the eyeball, and particularly by the pressure which the ocular muscles, and especially the orbicularis palpebrarum, at such times exert upon it. The perforation produced by such causes may develop with violent symptoms and entail very damaging results. After perforation has occurred we find the anterior chamber obliter- ated in consequence of the escape of the aqueous humor ; the iris and, in the region of the pupil, the lens also are applied to the posterior surface of the cornea. If the aperture made by the perforation is of suitable position and size, we see lying in it the iris which has been swept into the wound by the jet of escaping aqueous. The eye feels quite soft. Perforation is often preceded by a heratocele* For, Descemet's membrane being distinguished by the great resistance which, in com- parison with the corneal lamellaB, it offers to the inflammatory process, it often happens that the stroma of the cornea is destroyed throughout its entire thickness by suppuration, while Descemet's membrane still remains resistant. In that case it is protruded by the intra-ocular pressure under the form of a transparent vesicle which is visible upon the floor of the ulcer, or which may even project above the level of the adjacent cornea (keratocele or descemetocele). When this vesicle, too, ruptures, the perforation becomes complete. Sometimes the ulcer heals without the keratocele either rupturing or being flattened out. The latter then remains permanently under the form of a vesicle which pro- jects above the surface of the cornea, and which, itself transparent, is surrounded by a cloudy, cicatricial ring. The direct effect of a perforation upon the course of the disease is for the most part favorable, inasmuch as not only the pain and the other symptoms of irritation abate, but the progress of the ulcer also is, as a rule, arrested, and the ulcer rapidly becomes clean. The reason for this favorable influence is probably to be looked for in the fact that after the escape of the aqueous humor the intra-ocular pressure sinks considerably, and the resulting diminution in the tension of the cornea facilitates the circulation in the latter. The method in which the perforation in the cornea closes again varies according as it is placed in front of the iris or the pupil. If the opening is found in front of the iris, as is generally the case, it is quickly covered by the iris, which, after the escape of tlie aqueous humor, is driven forward as far as the cornea. In this way it becomes possible for the anterior chamber to be restored within a very short time, although, to be sure, the iris at the site of the perforation remains permanently connected with the cornea. If the perforation is quite * From Kepas, horn, and lefiKri, rupture. DISEASES OP THE CORNEA. 149 Fie. 46. -Partial PKOLArsE of the Iris (Schematic). The iris, which is thickened by the process of infil- tration, and is covered on its anterior and pos- terior surface by the exudate, e, ej, rises up be- tween the sharp edges of the mnrgins of the perforation, which are still infiltrated. Periph- erally from the prolapse the iris is approxi- mated to the cornea, although here a remnant, V, of the anterior chamber still exists. small, the iris simply applies itself to it from behind and there becomes solidly adherent. In case, however, the perforation is larger, the iris, as a rule, is driven into it by the escaping aqueous humor, and thus a prolapse or liernia of the iris is produced (Fig. 46). This is represented by a hemispherical prominence which, while re- cent, has the gray or brown color of the iris. Soon, how- ever, this color is changed be- cause of a layer of gray exuda- tion (e, Fig. 46) which covers the prolapse like a cap, and may be removed with a forceps. When the prolapsed portion of the iris is much stretched, the proper color of the iris is lost and the prolapse looks black, because of the retinal pigment on its posterior surface, which appears through the thinned stroma. This is particularly often the case in large prolapses of the iris. The extent of the prolapse of the iris is proportional, first of all, to the size of the perforation. In the worst cases the perforation may comprise the whole cornea, which has suppurated throughout ; in that case the iris prolapses through its entire extent {total prolapse of the iris, Fig. 47). The pupil is then gener- ally closed up by a plug of exudation {p). But the way in which the prolapse occurs has also an influence upon its size. If the perforation takes place with great force (e. g., while the patient is straining hard), or if the patient behaves in a restless manner after it has taken place, a relatively larger portion of the iris will be driven into the perforation. The cicatrization of a cor- neal ulcer, which is associated with a prolapse of the iris, oc- FiQ. 47.— Total Prolapse of the Iris (Schematic), Only the marginal portions, c, of the cornea are preserved, and these are still partially infiltrated. Between them bulges the iris, which is driven strongly forward and which consequently is thinned so that the pigment, i, upon its posterior surface shines through it and gives the prolapse a blackish hue. The pupil, p, is closed by a membrane. The space, h, between the ins and the lens is the enlarged posterior chamber. Of the anterior chamber only the shallow, slit-lilce, annular space, v, is left. This no longer commu- nicates anywhere with the posterior chamber (seclusio pupillse). curs in the following manner, if the prolapse is left to itself : The prolapsed iris in the first place becomes solidly agglutinated to the walls of the opening caused by the rupture, and wherever it is exposed it is converted by inflammation into 150 , DISEASES OP THE EYE. a sort of granulating tissue, so that the prolapse soon loses the color of the iris and becomes grayish-red. Subsequently there develops from the proliferating tissue of the iris cicatricial tissue, which first becomes visible under the form of isolated gray bands. By the contraction of these latter, constrictions are formed upon the surface of the prolapse. As the formation of the cicatrix proceeds, these bands become broader, fuse together, and render the prolapse constantly flatter and flatter. Hence in favorable cases the process terminates in the formation of a flat cicatrix situated at the level of the rest of the cornea, and at the site formerly occupied by the bulging prolapse. This cicatrix being mainly a portion of iris that has become cicatricial, it follows that the remainder of the iris still lying in the anterior chamber is solidly united to it. Such an adhesion of the iris to a corneal cicatrix is called an anterior synechia* Owing to the fact that the iris is drawn forward to the scar, the pupil loses its round shape and is drawn in toward the site of the adhe- sion. To what extent tliis is the case depends upon where the perfora- tion is situated and what part of the iris is prolapsed. In peripherally situated ulcers, it is a portion of the ciliary zone of the iris that pro- lapses into the corneal wound. In this case the pupil is drawn strongly toward the site of the perforation ; it has the shape of a pear, the sharp end of which is directed toward the site of the synechia. If, how- ever, the perforation is situated near the center of the cornea, the pupil- lary portion of the iris becomes engaged in it in healing (Fig. 46), and in this case the distortion of the pupil is slight, or entirely absent. If the perforatiou is so large that the entire pupillary margin of the iris is involved in the prolapse and becomes attached to the cornea in healing, the pupil is permanently closed by the cicatrix that is formed ; there are produced occlusio and seclusio pupillse, together with their de- structive consequences. In the healing of large perforating ulcers of the cornea, the shrink- ing of the cicatricial tissue is often so great that the corneal cica- trix appears flattened when compared with the normal curvature of the cornea. This flattening, moreover, may extend beyond the cica- tricial spot to the portion of the cornea which is still transparent, and which in that case becomes flatter over its whole surface {applanatio - cornecs). If the cornea has been entirely destroyed by suppuration, so that a total prolapse of the iris has developed, the latter ulti- mately becomes reduced to a small and perfectly flat cicatrix, which takes the place of the cornea {phthisis cornece). The distinction be- tween applanatio and phthisis of the cornea is as follows : In the former the cornea is still present, although it is in part cicatricial, and * From avvix^iv, to connect. The term lencoma adhiBrens (from AeuKiis, white) is also employed to denote a cicatrix of the cornea with anterior synechia. DISEASES OF THE CORNEA. 151 thus as a whole is flattened. In the latter, on the other hand, nothing of the cornea is left except a very narrow marginal rim, which gener- ally withstands the destructive process of ulceration. The flat scar which takes the place of the cornea is, in this case, the cicatrized iris. The healing of a prolapse of the iris with the formation of a fiat cicatrix must be regarded, even though the latter is opaque, as a com- paratively favorable outcome of a large corneal perforation. Such an eye, of course, is seriously impaired as regards its function, but yet, after the process has run its course, it remains in a state of quiescence, and generally causes its owner no further trouble. The case is differ- ent when healing takes place with the formation of an ectatic cicatrix. This occurs in the following manner : The prolapsed iris becomes cov- ered with cicatricial tissue, but this is not strong enough to effect the flattening of the prolapse. Hence the latter becomes consolidated in its original form as a protrusion, and is converted into an ectatic cica- trix with inclusion of the iris {staphyloma cornece). A large-sized per- foration opening and restlessness on the part of the patient favor the formation of such an ectasis. Whenever a prolapse of the iris has be- come so extensive that it is constricted by the margin of the perforation, and hence has acquired a mushroom shape, the formation of a flat cica- trix, without artificial aid, becomes altogether impossible. If the perforation in the cornea is not in front of the iris, but lies in the region of the pujyil, it can not be covered by the iris. Its occlu- sion in this instance takes place more slowly by an outgrowth of new- formed tissue (cicatricial tissue) from the margins of the opening, until the opening is filled up. In such a case the anterior chamber remains absent for a somewhat longer time, and meanwhile the lens is in con- tact with the posterior opening in the cornea. The lens may bear away permanent marks of this contact, most frequently in the form of a cir- cumscribed opacity at its anterior pole (anterior capsular cataract ; see § 89). If during cicatrization the delicate membrane occluding the opening is repeatedly ruptured (which generally occurs from improper behavior on the part of the patient), the perforation may end by re- maining permanently open, and a. fistula of the cornea is formed. This appears under the guise of a small dark point, surrounded by whitish cicatricial tissue ; the anterior chamber is absent, the eye is soft. If the fistula of the cornea persists for a long time, the eye gradually per- ishes. The cornea flattens out, the eye grows softer and softer, and at length goes blind from detachment of the retina. On the other hand, as soon as the fistula closes up, an increase of tension is apt to set m, that may lead to a renewed rupture of the occluding substance, which is still but slightly resistant. An alternation of this sort between an open fistula with softness of the eyeball, gradual closure of the fistula, and a consequent steady increase of pressure until the cicatrix ruptures anew, may be repeated for a long time, until finally a severe inflanima- 152 DISEASES OF THE EYE. tion occurs, which leads to the atrophy of the eye, and thus puts an end to the process. Other bad consequences of perforation of the cornea, which are sometimes observed, are : (a) Luxation of the Lens. — After the escape of the aqueous humor, the lens, to reach the cornea, must be pushed forward through the entire depth of the anterior chamber (2.5 millimetres), a movement associated with a considerable degree of stretching of the zonula of Zinn. If the forward movement takes place very suddenly, or if the fibers of the zonula have been rendered fragile by disease, the zonula ruptures. In consequence the lens may become tilted, or, if the perforation is large enough, may even be expelled from the eye. (J) Litra-ocular hcemorrhages are the result of the rapid diminu- tion in tension, by virtue of which an increased quantity of blood flows into the vessels of the interior of the eye, which have been thus sud- denly relieved of external pressure, and causes their rupture. Haem- orrhage takes place if the perforation occurs very suddenly, or if the eye beforehand was under an abnormally high tension. The latter is the case in glaucomatous and staphylomatous eyes, in which, further- more, there is generally also a degeneration of the vessels associated with an increased fragility of their walls. The haemorrhage may be so great that the entire contents of the eyeball are extruded by reason of it ; nay, more, the patient may almost be in danger of bleeding to death. (c) Suppuration starting from the cornea may be carried over into the deeper parts of the eye and lead to the destruction of the latter by purulent irido-cyclitis, or even by panophthalmitis. This occurs mainly in the case of extensive destruction of the cornea, especially if, at the same time, the suppuration is of a particularly virulent character, as in acute blennorrhoea or in ulcus serpens. The Clearing of Corneal Cicatrices. — After a long time has elapsed — months or years, that is — the cicatrix left by an ulcer appears less large and less opaque than it was directly after the healing of the ulcer was completed ; the cicatrix has partially " cleared up." In this way quite small cicatrices may become altogether invisible. The extent to which clearing takes place depends principally upon two circumstances : upon the thickness of the cicatricial tissue and upon the age of the indi- vidual. The deeper the cicatrix penetrates into the cornea, the less it clears up ; perforating cicatrices of the cornea, if they are ever so small, remain permanently opaque. (A fine example of this is afforded by the punctures which the discission needle makes, and which remain visible as gray points upon the cornea all during life.) The age of the individual influences the process of clearing, in that the latter makes greater advances the younger the patient is. For this reason cicatrices after blennorrhoea neonatorum often clear up in a wonderful way. DISEASES OF THE COENBA. I53 34. Etiology.— With reference to their etiology, all inflammations of the cornea may be divided into two great groups : primary and sec- ondary keratitides. By the former, we understand those which have their starting point in the cornea itself ; by the latter, on the contrary, those which have passed over to the cornea from other structures, and most frequently from the conjunctiva. This distinction, true with re- gard to keratitis in general, is especially so with respect to ulcers of the cornea. Primary ulcers of the cornea most frequently owe their develop- ment to traumatism. Under this head belong not only injuries in the narrower sense of the word, but also a lesion of the cornea by means of small foreign bodies, by faultily placed cilia, by papillary growths on the free border of the lids, etc. Primary ulcers, furthermore, de- velop after the separation of eschars produced by burns or the action of caustics. Other ulcers are dependent upon a disturbance in the nutrition of the cornea, as the ulcers in eyes with absolute glaucoma where the cornea has become insensitive, or ulcers which develop in old cicatrices of the cornea (atheromatous ulcers). Secondary ulcers are the results of an affection of the conjunctiva. All inflammations of the conjunctiva may be complicated with inflam- mations of the cornea ; and in severe inflammations of the conjunctiva, as in acute blennorrhoea and diphtheria, this is quite the rule. In accordance with our present views regarding suppuration we must expect to find that in the majority of cases the direct cause of the formation of ulcers in the cornea is constituted by the entrance of micro-organisms into the corneal tissues. We may have to do in this case either with specific organisms, as in the case of acute blennorrhoea, diphtheria, etc., or with the ordinary pus cocci. The latter are always found in the secretion of a conjunctiva affected with catarrh. If, now, owing to slight traumatism, to detachment of the epithelium by the formation of a vesicle (in herpes corneas), or to any other cause, the protective epithelial covering of the cornea is injured at some spot, the door is opened for the entrance of cocci into the tissue of the cornea. In people of the working class ulcers of the cornea occur much more frequently than among the well-to-do classes, because they very often suffer from neglected chronic catarrhs, and at the same time very fre- quently render themselves liable to injuries of the cornea. Treatment. — Ulcers of the cornea are very amenable to proper and energetic treatment. They hence in general afford a favorable prog- nosis if they come under treatment early ; in the great majority of cases it is possible to put a stop to their progress, and produce regular cicatrization. The treatment varies according to the stage in which the ulcer comes under treatment. («) Recent ulcers that are still foul (progressive) require, most of all, the consideration of the causal indication. In traumatic ulcers 154: DISEASES OF THE EYE. any foreign bodies that are.still present must in every case be removed. Cilia which are directed against the cornea must be epilated ; papillo- mata of the edges of the lids, when causing trouble in the cornea, must be removed. In the numerous cases in which the ulcer of the cornea is caused by a conjunctival lesion, the treatment of the latter forms, as a rule, the most important part of our therapeutics, and under it, moreover, the ulcer advances toward recovery. Hence, in corneal ulcers resulting from catarrh, trachoma, or acute blennorrhoea of the conjunctiva, we mnst by no means desist from cauterization of the latter, if it is required by the conjunctival trouble. The only precau- tion that must be observed is that the caustics applied should not come into contact with the cornea itself — a contingency which can be avoided by carefully washing off from the conjunctiva any excess that may be present. Furthermore, we should cauterize with the silver solu- tion only, and not with the copper stick, which is too irritating, and still less with the acetate of lead, which might lead to the formation of in- crustations of lead upon the cornea. Moreover, as long as progressive ulcers are present in the cornea, no irritating collyria, such as the col- lyrium adstriugens luteum and the like, should be instilled, as they would then come into contact with the cornea. The indicatio morbi requires in most cases the application of a bandage. Bandages are distinguished into protective bandages and pressure bandages, according as they are applied lightly or firmly. In recent ulcers a simple protective handage is sufficient. The object of this is to keep the lids closed and at rest without exerting any pres- sure upon the eyeball. The immobilization of the lids acts chiefly to prevent the floor of the ulcer from being swept by the lids with every movement of winking, which would give rise to constant irritation of the ulcer, and also to pain through contact with the nerve fibers lying exposed in it. Hence the pain is sometimes cut short at once by the application of a proper bandage. The bandage acts also to protect the ulcer from dust. The dust which is always falling upon the cornea is continually carried off by the movements of the lids ; but in the de- pression which constitutes the ulcer it is not reached by the lids as they sweep over it ; it consequently remains lying where it is, and may infect the ulcer. The bandage, as a rule, is to be kept on until the ulcer gets to be clean and becomes lined with an epithelial covering which protects the cornea against exterior influences. When the floor of the ulcer is thinned and shows a tendency to bulge, the use of the bandage must be kept up until the freshly formed cicatrix is sufficiently strong to offer resistance to the intra-ocnlar pressure. A contraindication against the bandage is furnished by a profuse secretion, because the latter would be retained in the conjunctival sac by the closure of the lids, and would remain in constant contact with the ulcer. For this reason, in ulcers resulting from conjunctivitis the DISEASES OF THE CORNEA. 15 5 bandage must be very often dispensed with. In quite small children, also, the bandage is generally useless, since it soon gets displaced ; and a badly applied bandage is more hurtful than any exposure of the eye could be. Next to the bandage atropine plays the most important part in the treatment of ulcers. It combats the inflammation of the iris, hence diminishes the general state of irritation, and so reacts favorably upon the ulcer itself. It must be instilled as often as is necessary, in order to keep the pupil steadily dilated. With these two remedies alone — the bandage and atropine — we attain our object in light cases. For those ulcers, however, which from the purulent hue or from the strong infiltration of their surrounding parts show a rapidly progressive char- acter, we must employ still other remedies. These are moist warm compresses, iodoform, subconjunctival injections, the actual cautery, and paracentesis of the anterior chamber. Moist warm compresses are made by taking a very light linen cloth folded several times, which simply covers the closed eye without press- ing upon it by its weight. Before being applied this is dipped in hot water and then well wrung out; and it must be changed frequently in order to be constantly warm. The warm compresses are applied every day for an hour or more, and the dressing must be left off each time for the same period. Very finely powdered iodoform may be sprinkled upon the ulcer itself. Stiiconjunctival injections of a l-to-1,000 sublimate solution may be also made beneath the bulbar conjunctiva. If in spite of these remedies the ulcer is evidently spreading, we must proceed to the operation of cauterizing the ulcer by means of the actual cautery (Gayet). For this purpose we use a small sharp-pointed cautery iron, or the galvano-cautery loop, or Paquelin's thermo-cautery. AVith one of these instruments the ulcer is cauterized wherever it shows a gray coating. In the case of extensive ulcers it is not necessary to cauterize the entire ulcerating surface, but it is sufficient to destroy the most infiltrated portion of its margin, at which an advance of the ulcer- ative process is to be expected. In performing the cauterization we make the cornea insensitive by the repeated instillation of a five-per- cent solution of cocaine hydrochloride. Another potent remedy for combating rapidly spreading ulcers is paracentesis of the anterior chamber (for the method of its perform- ance see the section on Operations, § 154). People were led to do this operation by observing that ulcers after spontaneous perforation generally went on to rapid healing. In a similar manner, artificial per- foration—!, e., puncture of the cornea— performed early prevents the extension of the ulcer and its threatened rupture. Why should we not wait until the ulcer spontaneously perforates the cornea? Because in 156 DISEASES OF THE BYE. the meantime the ulcer keeps enlarging superficially and thus would produce a more extensive opacity, and, furthermore, because after ulcer- ative perforation of the cornea a prolapse of the iris almost always develops, leading to the formation of an anterior synechia, while with a properly performed puncture this is not the case. If perforation is imminent, and we prefer not to bring it about artificially by puncture, we take care to have the patient kept quiet — a thing best done by making him lie in bed, in order that the perforation may take place slowly, and that as little as possible of the iris may be driven into the opening. (J) When perforation of the cornea has taken place treatment has to aim at the following objects : in the first place, that the iris shall not adhere to the cornea, or at least shall do so to the smallest possible extent ; in the second place, that a firm and fiat (not ectatic) cicatrix shall be formed. The two objects are attained as follows : 1. If the perforation is small the iris does not prolapse into it, but simply becomes applied to its posterior orifice. In such cases, rest, a bandage, and atropine suffice for the treatment. There then remains only a punctiform adhesion of the iris to the corneal cicatrix, and this is often subsequently drawn out into a thin filament. In particularly favorable cases no anterior synechia at all may be produced ; for in- stance, if the iris, before it has become firmly adherent to the site of perforation, is pushed away from it again by the reaccumulating aqueous. 3. If — in the case of a perforation of greater size — the iris has pro- lapsed, it should be excised. A replacement of the iris into the anterior chamber (reposition) is in most cases impossible of performance, and, even if it should succeed, would have no lasting results, since the iris would continually prolapse again. For the performance of excision we first make the cornea insensitive by means of cocaine. Then with a sharp-pointed instrument (conical sound) we separate on all sides the adhesions of the prolapse to the perforation opening, draw the iris as far as possible out of the wound with the forceps, and snip it off close to the cornea (Leber). If the operation has been successful, the iris ought no longer to be attached anywhere to the margin of the aper- ture ; on the contrary, there should be a coloboma of the iris with free pillars, as after a regular iridectomy. In this way we obtain a firm cicatrix without inclusion of the iris. The performance of excision is possible only in recent prolapses (prolapses a few days old), as afterward the prolapsed iris becomes so solidly adherent to the margins of the perforation that the separation of the iris from the latter is no longer feasible. Similarly it is not to be recommended in the case of a very large perforation. In these two cases — i. e., 3. In old or very extensive prolapses of the iris we abstain from re- DISEASES OP THE CORNEA. I57 leasing the iris from the cornea ; we confine ourselves to the attempt to transform the prolapse into a firm and flat cicatrix. In many cases a pressure bandage applied for a long time accomplishes this end. If we can not attain our object in this way, as is particularly the case when the prolapse is constricted at its base like a mushroom, we must produce flattening of the prolapse by repeatedly puncturing it or by excising a small portion. In the case of a very bulging total prolapse of the iris, it is advisable to split it transversely, and then, after open- ing the anterior capsule, to expel the lens. If there is a remnant of sound cornea left broad enough for the performance of an iridectomy, this operation is an excellent means for securing the formation of a flat cicatrix. 4. In keratocele, the maintenance of rest, the application of a band- age, and ultimately the puncture of the protruding vesicle, are em- ployed. 5. In fistula of the cornea, in order to effect its closure, everything must be avoided that might temporarily increase the ocular tension, and thus force the fistula open again just as it is closing. Tor this pur- pose we order rest in bed, with the application of a light bandage to both eyes, while at the same time we instill a miotic (eserine or pilo- carpine, see § 04) in order to diminish the pressure in the anterior chamber. An iridectomy has a very good effect, but this can be per- formed only when the anterior chamber has been, at least to some ex- tent, restored. If these measures fail, we must remove the cicatricial margins of the fistula either by excising or by cauterizing them (with a blunt galvano-cautery or thermo-cautery point) so as to fill the fistula up with new, firm scar tissue. If, however, we are going to perform cau- terization, there must be some remnant, even though a shallow one, of the anterior chamber present, as otherwise we should singe the anterior surface of the lens. (c) The treatment of ulcers in the regressive period, or period of cicatrization, should aim at filling the loss of substance completely with a resistant cicatrix, and at rendering the latter as transparent as possible. For the attainment of both objects irritants are employed. AYe begin cautiously with the weaker remedies, passing gradually, if these are well borne, to the stronger ones. One of the mildest of irritants is powdered calomel ; more energetic is the action of the yellow-precipitate ointment (from one to four per cent), the collyrium adstringeus luteum,* and tinctura opii crocata.f In applying the yellow-precipitate ointment, we insert it into the conjunctival sac [* See p. 33.] [f The tiuctura opii crocata of the Austrian Pharmaoopceia is made by extract- ing 10 parts of salfron with 100 parts of aqua cinnamomi aquosa (cinnamon-water containing 5 per cent of alcohol) and mixing the solution thus obtained with opium in the proportion of 10 parts of the former to 1 part of the latter. — D.] 168 DISEASES OP THE BYE. with a brush or glass rod, and then rub it about with the upper lid so as to perform a sort of massage upon the clouded cornea. Another irritant remedy that is recommended is nebulization — ^that is, the ap- plication of hot vapor (of water either alone or with the addition of irritant iiuids) to the cornea by means of an atomizer, such as is em- ployed for inhalation. It is advisable to continue the application of these irritants for a long time in order to secure the greatest possible clearing up of the cornea, but in so doing the remedies must be changed from time to time, as otherwise the eye gets accustomed to them and they lose their efficacy. Ulcers of the cornea are among the most frequent affections of the eyes, and special significance attaches to them because the opacities that they leave very often impair the sight. Ulcers of the cornea, if we except those resulting from conjunctivitis eczematosa, are found much more frequently in adults, and espe- cially in elderly people, than in children. It seems that in the later years of life the cornea is less well nourished, and is hence more disposed to disintegrate than in youth. The physician who is called to a patient with an ulcer of the cornea must, after examining the eye, have acquainted himself not only with the diagnosis but also the prognosis; he must tell the patient beforehand to what extent his sight will suffer permanent impairment, in order that such impaii-meot may not afterward be charged against the medical treatment. The prognosis for vision depends upon the situation, the extent, and the density of the opacity which the ulcer has left behind it. Small opacities, even when dense, are generally less injurious to vision than those which are less dense but extensive (§ 45). It is hence less serious for an ulcer to extend into the depth of the tissues than upon the surface. If an ulcer is progressing in the direction of the center of the cornea, every millimetre of advance causes additional injury to the vision, while an extension toward the corneal margin is almost a matter of indifference. No further disintegration is to be apprehended at those portions of the margin of the ulcer to which vessels have already penetrated, and so, too, a portion of the cornea, covered by pannus, is protected against suppuration in acute blen- norrhoea. In every instance the ulcer is arrested at the limbus, as it never makes its way into this or into the adjacent sclera. The only exception to this is formed by those ulcers which not infrequently develop from the nodules of conjunctivitis eczematosa situated in the limbus. Even extensive suppuration of the cornea, as in acute blennorrhoea, ulcus serpens, etc., always leaves a narrow rim of cornea intact, which, to be sure, is often not of sufficient size to render possible an iridectomy for the restoration of vision. Corneal ulcers occur under many various forms, some of which are well . characterized, partly by their etiology, partly by their aspect and course. These may be enumerated as follows : 1. In conjunctkitis eczematosa, as well as in conjvveti»itis ex acne rosarea, we find small, superficial, generally marginal ulcers, which, as a rule, get well rapidly. There are, however, cases of conjunctivitis eczematosa in which the ulcers, without spreading along the surface, keep on steadily penetrating deeper and deeper until abrupt crater-shaped losses of substance are produced which speedily perforate the cornea. These ulcers, too, are commonly situated at the DISEASES OF THE CORNEA. I59 margin of the cornea, and hence leave behind tliose peripheral incarcerations of the iris with marked displacement of the pupil that are characteristic of a con- junctivitis eczematosa which has run its course. 3. The 'caseular fasciculus (keratitis fascicularis) is likewise observed in con- junctivitis eczematosa, and is produced by an ulcer making its way from the margin of the cornea farther and farther into the latter, and trailing after it a leash of vessels from the limbus (page 94). 3. Catarrhal ulcers are cliaracterized by their crescentic shape, as well as by their position near the corneal margin, and concentric with it. 4. In pannus trachomatosus small ulcers frequently occur, which develop from the infiltration at the margin of the pannus. Sometimes along the margin of the pannus a whole series of such ulcers is found, which also may coalesce into one large crescentic ulcer. Other ulcers develop in the midst of the pannus in spots where the infiltration penetrates more deeply into the cornea and leads to ulcerative disintegration. 5. The central, non-irritative ulcer occurring in trachoma develops generally in the center of the cornea. It is distinguished by the abKence of accompany- ing symptoms of irritation, so that often the disturbance of vision is the only thing that calls the patient's attention to his trouble. Objectively, the ulcer is distinguished by the fact that even during the progressive period it is but very slightly clouded, so that it scarcely gives any evidence of its presence, except the loss of substance that it produces; it may therefore be very easily over- looked if we do not examine the cornea by carefully testing its reflex. It has a tendency to fill up incompletely with cicatricial tissue, so that a central facet remains which causes very great deterioration of sight by the production of ir- regular astigmatism. 6. Ulcers in acute hlennorrTuea anA in diphtheria of the conjunctira generallj spread rapidly, and often lead to destruction of the entire cornea, or even to panophthalmitis. 7. Traumatic ulcers of the cornea are, as a rule, small and superficial, and occur for the most part in elderly people. They are located in the zone of the cornea that lies in the palpebral fissure ; the upper third of the cornea, which is covered by the upper lid, therefore generally is exempt from them. But be- sides these ulcers, which run a rapid course and are benign, there also occurs — and usually after inconsiderable injuries— the dangerous sort known as ulcus serpens (see § 35). For the ulcers which develop as a result of desiccation of the cornea, see keratitis e lagophthalmo (§ 37). 8. Small marginal ulcers of the cornea occur frequently in elderly people, especially of the male sex, without any conjunctival lesion or external trauma- tism being discoverable as their cause. They develop with pretty violent com- plications, but are scarcely of the size of a pin's head, and heal rapidly without penetrating deeply. They are particularly troublesome from the fact that they are prone to recur, so that many people have to go through with attacks of this kind of keratitis one or more times every year. The uratic diathesis appears to be a frequent cause of these ulcers, and general treatment directed against this diathesis and consisting of the proper dietetic regulations or the use of mineral waters often puts an end to the recurrence of the ulceration. 9. Herpes comew febrilis (rarely also herpes cornece zoster, see § 43) may give rise to ulcers formed from the ruptured herpetic vesicles. These have the prop- 160 DISEASES OP THE EYE. erty of not penetrating deeply, but of being very prone to spread superficially. This superficial extension may take place in two ways: either the ulcer extends in all directions uniformly, in which case we have a large but quite superficial loss of substance everywhere surrounded by a narrow, sharp, usually festooned, gray, and infiltrated margin, which pushes its way farther every day (Pig. 48) ; or extension takes place in certain directions only. In the latter case, from the loss of substance, which originally is small, gray striae extend in one or more directions into the transparent cornea, and grow constantly longer, at the same time becoming forked, and also sending out lateral branches. Thus there is produced in the cornea a very pretty gray figure which is branched like a tree, and often bears nodular swellings at the extremities of its branches — keratitis dendritica (Emmert). This branched infiltrate breaks down into an ulcer having the form of a deep, branched furrow, with gray margins inclosing it (Fig. 49). Then this ulcer becomes clean and heals, leaving behind it an opacity, whose Fig. 48.— Large but quite Sd- PKRPiciAL Ulcer follow- ing Herpes Febrilis. The central gray ring corre- sponds to an earlier stage of the ulcer, which since then has advanced nearly to the margin of the cornea. Fig. 49. — Keratitis Dendri- tica. To the left of the large branched ulcer lies a group of delicate minute maculae, representlng_ the remains of the herpetic ef- florescences. Fig. 50.— Keratitis Stella- TA. The whole inner half of the cornea is moderately clouded and in it are four large and two very small ulcers, showing a stellate branching. branched form allows us to recognize, even some time afterward, the nature of the antecedent affection. In many cases of herpes, instead of a single large ulcer, numerous minute ulcers develop which are star-shaped and provided with short processes (kera- titis stellata (Fig. 50). All these forms of keratitis are characterized by their long duration (one to three months). 10. Ulcus rodena (Mooren). A superficial ulcer develops from the margin of the cornea (usually the upper margin) with marked inflammatory complications. Prom the sound portion of the cornea it is limited by a gray, clouded margin, which is evidently undermined. This latter symptom is characteristic of ulcus rodens. After a short time the ulcer begins to grow clean and to cicatrize, be- coming covered with vessels from the limbus. Just when one supposes the process to be nearing complete recovery, a relapse sets in with a return of the symptoms of irritation, and in this the ulcer pushes its way forward some- what farther in the cornea. So the disease goes on with discontinuous attacks and intervening remissions, until the ulcer has covered the entire cornea. The latter is thus everywhere deprived of its superficial layers, and hence remains permanently clouded throughout its entire extent, so that vision is very greatly diminished. Perforation of the cornea in this affection has never been ob- served. This rare disease attacks elderly people, and not infrequently invades both cornesB either simultaneously or in succession. It was regarded as incur- DISEASES OF THE CORNEA. 161 Fig 51 —Keratitis Margi- ^A^,IS SlIPERFICIALIS At the inner margin of the cornea is a pseudo-ptery- gium. able as long as surgeons were unacquainted with the cauterization of the cornea by means of the actual cautery. If, however, we destroy the margin of the ulcer by this means, the ulcer itself is sure to be cured. 11. Keratitis marginctUs superjicialis is another rare disease, found in persons in middle life. A quite superficial ulceration spreads over the cornea, starting from its margin. It does not, however, start from all parts of the margin at the same time, nor does it advance uniformly. Consequently the ulcerated mar- ginal zone of the cornea is demarcated from the trans- parent central portion by a sinuous border formed by a fine gray line (Pig. 51). This variety of keratitis drags on for a long time — sometimes for years — periods of intermission alternating with relapses, which are associated with moderate symptoms of irri- tation. It is distinguished from ulcus rodcns in that the ulcer is extremely shallow, and hence the cornea within its limits shows only a very faint and grayish opacity. Moreover, the edge of the ulcer, scarcely visible in any case, is not undermined. The ulceration never reaches the center of the cornea, so that the extremely faint opacities that remain do not interfere with sight. Kera- titis marginalis superficialis often gives rise to a drawing of the conjunctiva up over the cornea in the form of a pseudo-pterygium (see page 116). The vascular fasciculus, keratitis dendritica, ulcus rodens, and keratitis mar- ginalis superficialis have the common trait of creeping along slowly in the cor- nea, for which reason they are also designated by the name of serpiginous ulcers of the cornea. 12. Atheromatous ulcers develop in old cicatrices of the cornea when the latter have undergone degeneration through the deposition of lime or colloid masses or when they are exposed to mechanical injuries (as, for example, when at the apex of a corneal staphyloma). These ulcers torment the patient by the frequency of their recurrence and the associated symptoms of irritation ; they may also produce perforation of the cornea, and through this panophthalmitis. 13. In the eyes which are rendered blind by glaucoma ahsolutum, purulent ulcers, usually under tlie form of ulcus serpens, may develop. These are ordi- narily associated with considerable hypopyon, and frequently terminate either in perforation of the cornea with resultant hemorrhages from the eyeball or in panophthalmitis. Like atheromatous ulcers, they aie caused by insutHcient nutrition and innervation of the cornea, an insufficiency already made apparent from the insensitiveness of the latter. With both varieties of ulcers, the enu- cleation of the blinded eye is sometimes the only remedy that permanently re- lieves the patient of the repeatedly recurring tormenting ulceration. The treatment of corneal ulcers has very recently made great progress, chiefly because of the introduction of cauterization by means of the actual cau- tery, which we owe principally to Gayet ; for those very purulent and infiltrated, rapidly progressive ulcers that we hitherto were often powerless to oppose are just the ones that are usually arrested at once by this means. The application of the cautery is painless when cocaine is employed, and does not, as might be supposed, cause any marked irritation of the eye. On the contrary, after its application, the pain often ceases instantly, while the other symptoms of irri- tation abate. In private practice, when one has no other means to resort to, 11 162 DISEASES OF THE EYE. the head of a probe or of a knitting needle, heated red-hot, may be employed for cauterization. The chief thing is to make the cauterization extensive enough. Perforation of the thinned floor of the ulcer can, with care, be easily avoided ; should it occur, however, it lias no bad results beyond what the per- foration itself gives rise to, since the hot point is cooled at once by the out- pouring aqueous humor. An opacity remains permanently at the cauterized spot; but since we only cauterize such places as would otherwise go on to puru- lent disintegration, the final opacity is not greater than it would have been in any case. Among antiseptics, iodoform dusted in the form of a fine powder on the diseased spot is of most service. From other antiseptic remedies I have seen no special results accrue, at least when applied externally. However, sublimate under the form of auhconjunetwal injections has been repeatedly employed in corneal ulcers (Reymond, Darier). After the eye has been cocainized, a few minims of a l-to-1,000 sublimate solution (to which cocaine may also be added) are injected beneath the bulbar conjunctiva, not too close to the limbus. The injection is followed by pain as well as by marked congestion and swelling of the conjunctiva, the latter symptoms not usually disappearing until after several days. The injections are made at intervals of several days. Besides being em- ployed in suppurative processes in the cornea, they are used in parenchymatous keratitis, scleritis, iritis, and irido-cyclitis ; likewise also in chorioiditis and reti- nitis. Moreover, tile attempt has been made to apply them in purulent infection from wounds of the eyeball, whether consequent upon injury or upon operation. Subconjunctival injections of sublimate are mainly of service in progressive corneal ulcers ; in other sorts of cases the results obtained from them are rather uncertain. Eserine is employed by many in the place of atropine in purulent ulcers of the cornea. It seems to me, however, to have no action upon the corneal pro- cess itself, and, on the other hand, enhances the condition of irritation of the iris and leads to the formation of numerous posterior synechiee. It is more in- dicated in those cases in which there exists near the margin of the cornea a small perforation, to the posterior aperture of which the iris has become ap- plied after the escape of the aqueous humor. Here we may hope to produce, by means of eserine, so powerful a contraction of the sphincter iridis that the iris will be drawn away from the aperture, and thus the formation of an anterior synechia be prevented. On the other hand, if the site of perforation should be nearer the center of the cornea, so that the pupillary portion of the iris is ap- plied to it, we must employ atropine in order to draw the iris away from the opening. If, however, the iris has already fallen through the opening in the cornea, so that a real prolapse exists, neither atropine nor eserine, as a rule is able to release the iris from the wound and return it to the anterior chamber. In this case excision of the prolapse, as recommended by Leber, is the only remedy. Fistulm of the cvrnea mainly occur as a sequel of perforations that lie opposite the pupillary margin of the iris, so that the iris can not cover the opening com- pletely, but is simply attached by its pupillary border to the cicatricial tissue closing the gap. In this case, the iris, by continually dragging upon the cica- tricial tissue, prevents it from becoming consolidated. "While, then, such corneal fistulas do not as a rule present wide canals lined with epithelium, and while, on the contrary, we find the perforation opening filled with scar tissue, this DISEASES OF THE COENBA. Ig3 tissue is not dense, but is permeated by fissures through which the aqueous keeps oozing until it reaches the exterior surface of the cornea (Czermak). The origin of other flstulte is that the prolapsed iris splits apart under the strain produced by the pressure of the aqueous, and the opening thus formed never closes solidly again. Lastly, in very extensive prolapses of the iris, it may happen that in the process of cicatrization a fistula is left at the spot cor- responding to the pupil. It is usually hard to effect firm union in fistulse of the cornea. In some cases I have ultimately obtained success by sewing over the fistula a fiap taken from the adjacent conjunctiva. The flap by growing fast to the surface of the scar, whose epithelium had previously been removed, closed the fistulous open- ing. Another procedure consists in excising by means of the corneal trephine the fistula, together with the cicatricial tissue surrounding it, and implanting in the opening an equally large piece of healthy cornea. 5. Ulcus Serpens Cornem* 35. Symptoms. — A recent ulcus serpens appears under the form of a grayish-white or yellowish disk, which occupies nearly the cen- ter of the cornea. The opacity of the disk is greater at its edges than in the center, and generally the edges themselves show a particu- larly well-marked gray or yellow opacity in one special direction. The disk is surrounded by a delicate gray area, and frequently fine, radiat- ing, gray stris extend from the margin of the disk into the transpar- ent part of the cornea. The surface of the cornea over the disk is dot- ted, and often at the beginning is raised some distance above the level of the surrounding parts. Soon, however, this spot is seen to be de- pressed, although not with abruptly depressed edges, as in the case of an ulcer, but rather under the form of a shallow dimpling. Moreover, the rest of the cornea that is not occupied by the serpent ulcer proper is less lustrous, being covered with a delicate uniform cloudiness. These changes in the cornea are always associated with a violent iritis. The aqueous humor is turbid, a hypopyon lies at the bottom of the anterior chamber, the iris is discolored and is fastened by posterior synechiee to the lens capsule. Corresponding to the severity of the inflammation is the violence of the irritative symptoms : slight oedema of the lids, intense injection of the conjunctival and ciliary vessels, photophobia, and pain, which latter often reach a very considerable height. Nevertheless there are also torpid cases, which are associated with very slight symptoms of irritation. The subsequent course consists in the enlargement, both super- * Synonymous terms for ulcus serpens corneEe (Saemisch) are hypopyon kera- titis (Roser) and abscess of the cornea. The latter name, used by the older authors, I myself employed to denote the affection in former editions of this text-book, but the name ought to be given up, since in ulcus serpens there is no actual abscess cavity in the cornea. 164 DISEASES OF THE EYE. ficially and in depth, of the serpent ulcer. The superficial enlargement takes place chiefly in that direction in which the margin is marked by a specially dense opacity — an opacity which not infrequently looks like a yellow crescent placed upon the serpent ulcer. Inasmuch as the anterior lamella of the cornea within the region occupied by the ulcus serpens keep breaking down more and more, there is formed an exten- sive ulcer, the floor of which is coated with pus. Soon after this, gen- erally, those lamellse of the cornea which now form the base of the ulcer are also destroyed, so that an extensive perforation of the cornea is produced. The contents of the anterior chamber, consisting of aqueous humor and pus, are evacuated, and a large prolapse of the iris forms. While the ulcus serpens is going through with its process of devel- opment, the accompanying iritis keeps on increasing in the same pro- portion up to the time of perforation of the cornea ; the hypopyon, too, keeps growing until it tills the greater part of the anterior chamber, and the pupil is closed by an exudation membrane. After the perforation of the cornea has taken place the irritative symptoms generally abate and the suppuration may now come to a standstill. In other cases, however, the purulent disintegration of the cornea keeps on just the same, so that the latter is entirely destroyed, with the exception of a narrow marginal rim. Panophthalmitis may even result from the suppuration passing over into the deep parts. An ulcus serpens always leaves a very dense corneal cicatrix which can not be cleared up, and in which the iris is almost always incarcer- ated. Furthermore, in consequence of the iritis, there are usually left adhesions of the iris with the capsule (posterior synechias), and even a closure of the pupil by a membrane (occlusio pupillse). The corneal cicatrix itself is in favorable cases flat, in unfavorable cases ectatic, so that the ulcus serpens ends by forming a staphyloma. If panophthal- mitis has followed upon the ulcus serpens, a shriveling up of the eye (phthisis bulbi) takes place. The clinical picture which is characteristic of ulcus serpens and by which the diagnosis is made is only present in the beginning of the dis- ease. Its important features are the dislcUlce form and central situation of the opacity, the more pronounced opacity of the margin in comparison with the center, the character of the corneal surface, which, at the site of the ulcus serpens, shows only a shallow depression, and finally the early onset of hypopyon and iritis. 1\\e prog7iosis of ulcus serpens is always serious, as, on account of the malignancy of its course, it belongs to the most dangerous of the diseases of the eye, and, if not checked early, it generally ends by pro- ducing blindness through an incurable opacity of the cornea. And even in the favorable cases, which either spontaneously or with the help of art come to a stop early, a dense, centrally situated opacity re- DISEASES OP THE CORNEA. 105 mains, so that usually the sight can only be restored by the perform- ance of an operation (iridectomy). 36. Etiology. — An ulcus serpens originates in infection of the cor- nea by organisms (the pneumococcus) which set up in it a purulent inflammation. Such infection presupposes two conditions : first, a le- sion of the corneal epithelium, which in the normal state protects the cornea against the entrance of micro-organisms ; and, second, the pres- ence of pyogenic organisms which find their way to the spot where the epithelium is wanting. Both of these conditions occur in many cases of injury of the cornea. The body which inflicts the injury may itself be the carrier of infection and inoculate the cornea with germs. Much more frequently the inJLiry, by producing a loss of substance in the epithelial covering, simply affords the opportunity for the entrance of infection, the infecting germs being furnished by the secretion con- tained in the conjunctival sac. The injuries which in this manner lead to the formation of ulcus serpens are, as a rule, very slight, consisting in a simple scaling off of the epithelium. Among such injuries, for example, is the scratching of the cornea with the finger nail, a thiug which children very often do to their mothers who are carrying them in their arms. A rough cloth, a leaf, or a branch grazing the cornea, and small foreign bodies, especially minute fragments of stone, which fly into the eye, likewise produce these superficial injuries. Even in those cases in which a typical ulcus serpens has appeared to originate spontaneously, it is probable that there has been an antecedent injury, since such slight injuries of the cornea as these are readily overlooked by the patients. In exceptional cases severe perforating injuries, and in a similar way operation wounds, may also give rise to an ulcus serpens. Associated with the injury, as the second factor in the production of ulcus serpens, is the presence of a chronic lesion of the conjunctiva (catarrh or trachoma), or a blennorrhcEa of the lachrymal sac (present in about one third of the cases of serpent ulcer), by which the infecting secretion is furnished. Traumatic ulcus serpens attacks adults exclusively, and especially those belonging to the working class. These are more frequently ex- p^osed to injuries of all kinds, and, besides, more often suffer from neglected affections of the conjunctiva and lachrymal sac than do mem- bers of the well-to-do classes. Great heat favors the formation of ulcus serpens, which is hence much more frequent in the hot season than in winter. For this reason reapers are not infrequently affected with the disease, since in cutting the grain they scratch their eyes with its awns, and, besides, they do their work during the hottest days of the year. Stone masons also are particularly apt to be attacked by ulcus serpens. In ulcus serpens resulting from acute blennorrhcea and from diph- theria of the conjunctiva there is likewise without doubt a penetration of phlogogenic germs into the cornea from the conjunctiva. 166 DISEASES OF THE EYE. Ulcus serpens also occurs in acute infectious diseases, such as small- pox, scarlet fever, measles, typhus, etc. The form that results from variola is most frequently observed. In this case it makes its appear- ance not at the height of the disease but in the stage of desiccation, and, in fact, sometimes even in patients who have already left their beds. These variolous ulcers are found in children as well as in adults, and not infrequently affect both eyes so that total blindness may be produced by them. Since the ulcus serpens in variola develops such a length of time after the stage of eruption, it obviously can not be regarded as a small- pox pustule that has been localized upon the cornea. Hence in this case as well as when occurring with other infectious diseases, it has been considered to be a metastatic affection. If the metastasis is sup- posed to occur in the way of embolism, we should have to assume, since the cornea itself is bloodless, that the embolus is arrested at some point in the marginal network of vessels surrounding the cornea, and that acting from this point it sets up the suppuration. But the clinical picture presented by ulcus serpens, which is a process that begins in the center of the cornea, does not agree with this view. Hence ob- servers are now inclined to the belief that the variolous ulcer, like other ulcers, is to be referred to infection from without. There is no lack of opportunity for such infection to take place, since the free border of the lids is a favorite seat for variolous pustules, which thus can come into direct contact with the cornea. Treatment. — In consideration of the rapid progress which an ulcus serpens usually makes, and which threatens the entire cornea with de- struction, a particularly prompt and energetic interference is required. The treatment is partly medicinal, partly operative. The medicinal treatment is the same as in purulent ulcers of the cornea — namely, the application of a bandage, atropine, iodoform, moist and warm compresses, and subconjunctival injections of sublimate. At the same time, any lesion of the conjunctiva or lachrymal sac that may happen to be present is to be suitably treated. This treatment is only adapted to the case of small recent ulcers without an excessively large hypopyon. It should be undertaken only under the condition that the disease is closely watched, so that in case the latter progresses in spite of it, we may immediately proceed to operative treatment. Operative treatment must be initiated without delay in all severe cases of ulcus serpens, but is also required in the lighter cases when they resist the mild treatment. It consists either in the cauterization of the ulcer by means of the actual cautery or in its incision according to the method of Saemisch. Gaiiterization is performed in the same wav as in the case of progressive ulcers of the cornea; special attention must be paid to the destruction of the progressive portion of the mar- gin. Cauterization has the advantage over incision of not causing a DISEASES OF THE CORNEA. 16Y perforation of the cornea, and hence of not giving rise to inclusion of the iris. It is suitable, however, only for those ulcers that have not yet undergone perforation, and in which the hypopyon is not ex- cessively large, for the latter is not removed from the eye by this method ; it can disappear from the anterior chamber only by resorption. Incision of the ulcus serpens (puncture by Saemisch's method, see the section on Operations, § 154), beside dividing freely the corneal lamellas, which are saturated with pus, also effects the evacuation of the hy- popyon ; it, however, entails the disadvantage of a frequently extensive incarceration of the iris. Incision is suitable for very extensive ulcers, for those in which perforation is imminent, and for those which are associated with a large hypopyon. We should not let the matter rest with a single performance of the incision, but must every day separate anew with a blunt instrument the edges of the wound, as they speedily reunite, and we must keep this up until the ulcer begins to grow clean. At the same time that this operative procedure is being performed, the medicinal treatment above mentioned must be continued. Perforation and prolapse of the iris, when once they have occurred, must be treated according to the plan that has been laid down for perforating ulcers (page 156). According to our present views, purulent inflammations everywhere are, with rare exceptions, to be referred to the presence of ScMzomycetes. In the special case of pamlent inflammation of the cornea, the presence of fungi has for a long time been a matter of demonstration, the principal organisms found being the staphylococcus, streptococcus, pneumobacillus (of Friedlander), and the pneumococcus (of Friinkel and Weichselbaum). The last named is the most frequent exciting cause of the typical ulcus serpens, which possibly owes its very peculiarities to the special properties of this germ (Uhthofi and Axen- feld). In rare cases mold fungi (Aspergillus fumigatus) have been found as the cause of suppurative keratitis. The micro-organisms, whose presence in the suppurating cornea has been demonstrated, are also without doubt the real exciting cause of the suppura- tion. Traumatism alone, without infection, does not give rise to suppuration. We may cut, scrape, crush, or, in short, injure in any way, or even cauterize the cornea of an animal without getting any purulent inflammation of it ; in every case simply a gray cloudiness develops, which generally disappears again quickly. But when, by repeatedly touching the conjunctiva with nitrate-of- silver solution, we have artificially produced a conjunctival catarrh, and in this way have given the opportunity for the production of infection, we then see purulent infiltration follow upon these same lesions of the cornea (Thilo.) What is true of the cornea of animals is also true of that of man. Provided we avoid infection by cleanliness and antiseptic measures, we can with impunity subject the cornea to operations both light and severe ; even crushing of the cornea, such as, for example, is often enough produced in the expression of a cataract, does not always by any means lead to suppuration. But if we undertake the same operation in the presence of a conjunctival catarrh or a suppuration of the lachrymal sac, we risk the loss of the eye from a purulent infection of the wound. 168 DISEASES OP THE EYE. In what way does infection of the cornea by pus germs lead to the develop- ment of a suppurative heratitis f We owe our knowledge in regard to these processes and the true explanation of them chiefly to the investigations of Leber, who made inoculations of various kinds of germs upon the corneffl of animals. The morbid processes that he observed to result from these inocu- lations he refers to the toxic eflect which the products of the tissue metamor- phosis of the cocci induce. He assumes that the chemical substances produced by the cocci exert upon the cell protoplasm an irritant action, when but slightly concentrated, and, when more concentrated, a paralyzing and ultimately fatal eflEect. When pus cocci are introduced into the cornea by inoculation they first increase in number within the corneal tissue. Then the cornea for a cer- tain distance about the colony of cocci dies, because the toxic substances ex- creted by the cocci are present within this area in a state of strong concentration. According- ly, the colony of cocci now lies in the center of the necrotic area (Fig. 52). In the meantime violent inflammatory symptoms have made their appearance in the eye. The toxic substances by diffusion have reached the margin of the cornea, and there cause dilatation of the vessels and in- creased permeability of the vessel walls, entail- ing as a necessary consequence increased diape- desis of the blood plasma. In addition to this diapedesis of serum an emigration of white blood corpuscles also takes place from the ves- sels. This is effected by active movements of tlie leucocytes, which, irritated by the toxic substances, emigrate toward the focus of inflam- mation (chemotaxis). This migration of thb leu- cocytes may be explained in the following man- ner: The degree of concentration of the toxic substances diminishes gradually from the spot where the irritation originates to the periphery. Hence, that side of the body of a leucocyte that is turned toward the starting point of the irritation is in contact with a more irritating fluid than is the side which is turned in the opposite direction. Hence the protoplasmic processes push out more on the former side than on the latter, and the whole cell consequently moves toward the source of irri- tation. The leucocytes, however, do not make their way into the necrotic district itself, the pus cells that are found there being such as have emigrated from the conjunctival sac. In fact, the leucocytes derived from the margin of the cornea are paralyzed at the border of the necrotic area owing to the great degree of concentration of the toxic substances at this spot. Thus it happens that a constantly increasing number of cells are arrested at the margin of the necrotic spot, and die there. In this way is produced the infiltration (or mi- gration) ring, which is apparent to the naked eye. Now leucocytes have the property of dissolving by a kind of digestive action tissues in which they are present in large quantities. They effect by this means the exfoliation of the necrotic area, and give rise to a delimiting suppuration. The inflammatory phenomena in the cornea, consequently, appear under the guise of a process Fig. 52.— Inoculation Keratitis. (After Leber.) Magnified 3x1. Surface section through a rabbit's cornea, into the center of which a dilute suspension of Staphylo- coccus aureus had been injected three days before. In the middle of the cornea is seen the mass of Eroliferating cocci, surrounded y a necrotic zone. This latter is bordered by a broad migra- tion ring, adjoining which below there is a second one, narrower and not complete. DISEASES OP THE CORNEA. 169 having a definite purpose to subserve, the principal end and object of which are to eliminate the necrotic area, and with it the morbific agents that it con- tains. But beside this the pus corpuscles, as experiment has shown, have the additional property of directly inhibiting the growth of germs, so that they oppose the diffusion of those schizomycetes that may have chanced to grow out beyond the necrotic mass. Since the cornea is an organ which extends mainly in one plane, the migra- tion zone does not form a spherical shell, but a ring. Yet, according to Leber, migration is not wanting on the posterior surface of the cornea also. The way in which this occurs is, that first the endothelium of Descemet's membrane over the necrotic area becomes detached and a clot of fibrin is precipitated from the aqueous upon this portion of the posterior wall of the cornea. Then leucocytes migrate into the clot, so that soon a plug of pus can be seen on the posterior surface of the cornea at a point corresponding to the site of the inoculation. This pus, by sinking down to the bottom of the anterior chamber, forms the hy- popyon. Leber's experiments were all made upon animals, in which it is not possible to produce a morbid picture perfectly similar to the ulcus serpens in man. And, for reasons that will be readily comprehensible, anatomical researches on human eyes affected with ulcus serpens do not exhibit its early stages, whose anatomical character must be inferred from what is found to obtain in the more advanced cases. I have in my possession preparations made from nine cases of ulcus serpens (including four of Dr. Elschnig's), and from the concurrent testi- mony of these the course of the disease shapes itself as follows : An infiltrate forms in about the center of the cornea. This infiltrate is like that represented in Fig. 38, but is somewhat more superficially placed, and, on the other hand, is denser. The corneal lamellae placed over the infiltrate become necrotic, and then swell up and exfoliate. Thus, in place of the infiltrate there is formed a flat open ulcer, the floor of which consists of fibers of the cornea, that have been heaved up and are swollen to an almost homogeneous mass, and between which only a very few, sparsely scattered pus corpuscles are to be seen. It is only at the margins of the ulcer that the remains of the infiltrate can still be distinguished, and here it penetrates— appearing in cross section like a wedge —into" that portion of the cornea that still is sound (Fig. 53 C, a). This residue of infiltrate corresponds to the yellow, advancing border of the ulcus serpens; it keeps insinuating itself farther and farther along between the tamelljB of the cornea, so as first to lift up and then to detach the layers that overlie it. In many cases of ulcus serpens the infiltration of the margin soon disappears at some portion of its circumference, so that the ulcer advances in one direction only. This progressive portion of the ulcer's border then looks like a yellow crescent (Fig. 53 J, a) applied to the disk-shaped ulcer, which itself is often so little clouded that one can scarcely recognize it except by the shallow depression that it produces in the surface of the cornea. In this case wherever in the living eye the yellow margin is no longer visible anatomical dissection shows the wedge-shaped infiltrate to be absent (Fig. 58 C, I). At this point the epithelium passes over the edge of the ulcer and out upon its floor, covering the latter in an irregular uneven layer, often as far as the ad- vancing portion of the border. This fact explains why such ulcers give an almost mirrorlike reflex. It would, however, be erroneous to assume that the portions of the cornea that have once more become covered in this way with 170 DISEASES OP THE EYE. B Fig. 53.— Ulcus Serpens. A^ front view ; .B, cross sec- tion. Magnified 3.} X 1. C, cross section. Magnified 20 X 1. In tliis, as in most of the cases of ulcus serpens that have been examined anatomically, the eye was af- fected with absolute glaucoma. The ulcer occupied about the center of the cornea ; its upper, advanc- ing border, a. was clearly recognizable as a .yellow crescent, while the lower border, being but slightly opaque, did not specially stand out against the sub- jacent masses of pus which lay in the anterior chamber and extended as low down as c. Farther below, between the cornea and the iris, is seen the hypopyon, the upper border of which (d) is convex. Owing to the glaucoma, the iris has, rather pecul- iarly, become adherent by its periphery to the cor- nea, e, posterior abscess in the cornea. ute to the production of perforation. Here takes place early, and these migrate toward their way mainly along the posterior surface epithelium have healed. Nature tries to cover every wound with epithelium as rapidly as possi- ble, in order to protect it from the outside world. In such a case it often happens that the epithelium covers masses of dy- ing tissue, and even masses of pus. So also in Fig. 53 0, we see at a how the epithelium has grown over the advancing por- tion of the border, which is on the very point of disintegration. Moreover, those lamellis of the cornea that lie directly beneath the epithelium and form the floor of the ulcer are no longer capable of surviving; they are swollen up, destitute of corneal corpuscles, and contain only a few pus cells. The deeper-lying lamellse are apparently normal ; but upon careful examination it is found that no corneal corpus- cles susceptible of staining can be distinguished in them, so that they also in large part are on the way to destruction. Hence it is that although in ulcus serpens the purulent infil- tration does not go very deep, nevertheless very extensive per- foration of the cornea occurs. The changes which simulta- neously take place at the poste- rior surface of the cornea contrib- an accumulation of pus corpuscles the inflammatory deposit, making of Descemet's membrane. They DISEASES OP THE CORNEA. 171 are derived from the vessels of the uvea, and chiefly from the vessels surround- ing the sinus of the anterior chamber ; and as proof of their origin, many of them contain small granules of pigment derived from the uvea. The pus cor- puscles congregate to form a mass of pus upon the posterior wall of the cornea ; they then penetrate into Descemet's membrane and ultimately into the cornea itself. In this latter, therefore, there is formed a sort of posterior abscess (Fig. 53 G, e) at a point corresponding to the site of the ulcus serpens. Directly in front of this abscess lie those corneal lamellae which, as already mentioned, are destitute of corneal corpuscles and are undergoing dissolution ; and their necrosis in conjunction with the abscess gives rise to the perforation of the cornea. If we compare these observations with the results obtained in Leber's experiments upon rabbits, we must regard the posterior abscess and the wedge-shaped infiltration at the advancing margin as parts of the migration zone. The pus of the posterior abscess, which lies within the cornea itself, is in direct communication with the purulent masses that are applied to the posterior surface of the cornea. These latter form coherent lumps (c. Fig. 53 C), which sink to the bottom of the anterior chamber until they unite with the hypopyon {d, Fig. 53 C) present there. In the living eye these masses of pus upon the pos- terior surface of the cornea often render it impossible to make out precisely the limits of the ulcus serpens, inasmuch as the latter does not contrast sufficiently with the yellow background made by the pas (Fig. 53 A). The hypopyon has usually a border that in front view appears convex upward (Fig. 53 A, d). It is, moreover, agglutinated to the posterior surface of the cornea (Fig. 53 C, d), so that when we look into the anterior chamber from above we can see down between the hypopyon and the iris. The older authors were well acquainted with tliese appearances, but gave them a different interpretation. They regarded the thread of pus extending dovrn into the anterior chamber as a hypopyon situated in the cornea itself, assuming that the pus settled down between the corneal lamellae. They explained the flattened shape of the hypopyon and the convex curve of its upper border as being due to the contracted space occupied by the pus inclosed between the corneal lamellae. On account of the convexity of its upper border they compared the hypopyon to the lunula of the finger nail, and hence called it unguis or onyx (nedl). These expressions would therefore .denote a settling of pus down between the lamellae of the cornea — a phenomenon, however, that does not actually occur. The variety of keratitis produced by mold fungi Qceratomycosis aspergillina) presents even upon external examination a clinical picture differing from that of the ordinary ulcus serpens. There forms in the central portions of the cor- nea an infiltrate which later undergoes superficial disintegration, and is distin- guished by its peculiar, dry, crumbly surface. About this area a gray or yellow annular line of demarkation forms, which gradually deepens into a gutter and ultimately leads to the exfoliation of the inclosed portion of cornea, which in the meantime has become necrotic. The latter being thus detached en masse from the cornea, cicatrization of the resulting loss of substance ensues. Hypopyon is present, but the irritative symptoms are slight, and the whole course is very chronic. Examination of the sequestrum shows it to be permeated by a growth of the mycelium of the Aspergillus fumigatus. It is probable that, as a general 172 DISEASES OF THE EYE. thing, this fungus is carried into the cornea by the foreign body that caused the original injury. A keratitis that has a certain resemblance to ulcus serpens consists in the development in the middle layers of the cornea of a gray, disk-shaped opacity, •which is sharply limited by a border of deeper gray from the transparent periphery of the cornea. In the center of the disk a small, more deeply clouded speck is commonly observed. The gray border of the disk may be made up of several concentric circular lines. This disk- shaped infiltrate never becomes yellow and never leads to disintegration of the cornea; only excep- tionally a small loss of substance develops over a circumscribed area. The irritative symptoms are mostly not very pronounced, and hypopyon is absent or but scanty. The course of the disease is a protracted one, as it takes one or more months for the eye to become free from congestion and for the infiltrate to be transformed into a corneal opacity. This latter is permanent. In the course of the disease it often happens that -scattered, superficial, or deep-seated blood-vessels develop which extend into the infiltrate. Cases of similar nature were described by the older ophthalmologists under the name of abseessus siccus, by which term they meant an abscess in which no suppuration had occurred. In reality it is likely that in these cases, as well as in ulcus serpens, infection of the cornea from without lies at the bottom of the trouble. In argument for this view it may be said that the central graj'er speck represents the point of entry of the bacteria and the gray marginal line the migration zone. The dis- tinction between this and ulcus serpens would consist in the fact that the inflammation does not advance to the point of supjDuration, and the reason for this may be that we have here to do with bacteria that give rise to a milder, non-suppurative form of inflammation. The way in which the infiltrate origi- nates is not known, since no history of injury is given by the patients, and usu- ally, too, there are no lesions of the conjunctival or lachrymal sac present. The disease has a certain resemblance to keratitis profunda (see § 43), in which likewise a deep-seated, gray, non- ulcerating infiltrate develops in the center of the cornea. But this is composed of gray strias and maculfe, and merges gradu- ally into the transparent cornea. The infiltrate here described, on the contrary, appears uniformly gray and only under a very high magnifying power can be resolved into extremely minute, well-defined, white, closely agglomerated points ; moreover, it is quite sharply separated from the healthy cornea by the gray circular line forming its border. The annular abscess of the cornea usually occurs after perforating injuries of the latter, and also after operations (especially cataract operations). No mat- ter where the corneal wound that gives rise to it is situated, it develops in the central portions of the cornea as a yellow ring which is concentric with the limbus and is separated from it by a slightly cloudy marginal zone, one to two millimetres broad. The ring itself has about the same width ; the central por- tions of the cornea inclosed by it are again less cloudy and simply gray, not yellow. In the next few days, however, the yellow coloration spreads over the entire cornea ; the latter disintegrates completely, and not infrequently panoph- thalmitis ensues. Here accordingly we have to deal with an afl'ection of the cornea of a peculiarly fulminating course, so that it is best to enucleate at once such an eye affected thus with annular abscess. The treatment of ulcus serpens had in general but little success to chronicle until Saemisch substituted the operation of incision for that of paracentesis, of DISEASES OF THE CORNEA. 173 iridectomj', etc., previously in vogue. In performing the operation -we raust take care not to injure the lens and not to let the escape of aqueous take jslace too suddenly. The hypopyon is either evacuated spontaneously, especially if the patient makes pressure with his lids, or it can be grasped by means of a for- ceps introduced into the wound, and drawn out. For, in ulcus serpens, it is not thin and liquid, but of a tenacious, viscid consistence. In consequence of the diminution of pressure after the escape of the contents of the anterior cham- ber haemorrhages often take place from the iris, which, already hypersemic be- fore the operation, now becomes still more distended with blood. This is probably the cause of the violent pain which regularly follows upon the evacu- ation of the contents of the anterior chamber, although the incision itself is but little felt. After incising the ulcus serpens we always get an attachment of the iris to the cornea during healing, which, however, would not have failed to occur, even apart from the operation, in tliose cases in which incision is indi- cated at all. Recently an old, partly forgotten procedure has been again brought into use. This consists in scraping the ulcus serpens with a small sharp spoon. The loss of substance thus produced may be brushed over with antiseptic substances or with iodoform. Prophylaxis against the formation of an ulcus serpens is possible in the sense of our being able to remove iu season the source of infection, as, for instance, the secretion from a lachrymal sac affected with blennorrhoea. If, in such a case, a small erosion of the cornea exists, this is to be treated with special care by the application of disinfectant remedies. Even in cases of varioloui vlcers of the cornea prophylaxis undertaken in season would often prevent the infliction of great injury. During an eruption of smallpox the lids are much swollen, and hence are not opened by the pa- tient, and even the physician generally neglects to look at the eye from time to time. In that case, when the swelling of the lids goes down during the stage of desiccation and the patient opens his eyes again the morbid process in the cornea is often already in pi-ogress, and we are just so much behindhand in un- dertaking the treatment. Horner, therefore, is right in demanding that a physician treating a smallpox patient should prevent the agglutination of the lids by applying a pledget smeared with ointment, should examine the eyes every day, and should cleanse the conjunctival sac with antiseptic solutions. Careful watching will enable us to recognize the very commencement of the corneal disease, which in these early stages presents the most favorable condi- tions for treatment. At the time when smallpox was very widespread it formed one of the most frequent causes of blindness, so that about one third of all cases of blindness were produced by it. Since smallpox, owing to the in- troduction of vaccination, has become less prevalent, the blindness due to it has correspondingly diminished. Thus, in France, before the introduction of vaccination, thirty-five per cent— and after its introduction seven per cent— of all the blind lost their eyesiglit by reason of smallpox (Carron du Villards). In Prussia, before the introduction of compulsory vaccination, thirty-flve per cent— after its introduction two per cent— of all the blind people in the coun- try were rendered so by smallpox. 174 DISEASES OF THE EYE. S. Keratitis e LagophtJialmo. 37. Keratitis e lagophthalmo originates from a desiccation of the cornea in consequence of its being insufiSciently covered by the lids. The conjunctiva of the eyeball, wherever it lies constantly exposed to the air in the open palpebral fissure, appears reddened, and generally somewhat swollen as well. It secretes a small amount of discharge, drying upon the conjunctiva in crusts, which not infrequently also cover the exposed portion of the cornea. After removing the crusts we find the cornea dry on the surface, dull, slightly depressed, and at the same time clouded and gray. In the subsequent course of the disease the cloudiness becomes more and more intense, until finally disintegration of the superficial layers of the cornea takes place, with the consequent formation of an ulcer. At the same time there exists iritis with hypopyon. The ulcer may heal without perforation, but leaving an opacity behind it, or it may perforate the cornea, and thus lead to prolapse of the iris, or even to panophthalmitis. The cause of keratitis e lagophthalmo is the desiccation of the cor- nea in consequence of the defective closure of the lids (lagophthalmus). Owing to this desiccation the corneal epithelium becomes fissured and desquamates in spots. Then germs migrate into the corneal lamellae thus exposed, and produce suppuration. The defective closure of the lids arises either from mechanical ob- stacles, such as contraction of the lids, marked protrusion of the eye- ball, etc., or from paralysis of the orbicularis palpebrarum. In high degrees of lagophthalmus the cornea is uncovered all the time ; in lighter cases, on the contrary, in which the closure of the lids is not impossible but only impeded, the danger of desiccation taking place is particularly present during sleep. In daytime, owing to the feeling of dryness of the cornea, the act of winking is pretty frequently excited through reflex action, and thus the cornea is repeatedly moistened. But in sleep the reflex winking of the lids is absent, and hence the cor- nea is unmoistened by this means and becomes dry wherever it lies ex- posed in the open palpebral fissure. The desiccation in this case always affects the lowermost part of the cornea, because in sleep the eyeball is turned upward, and hence the lower part of the cornea lies in the pal- pebral fissure. The corneal lamellse, as fast as they become desiccated, die and are cast oflE by a process of suppuration. An ulcer is then produced which extends below as far as the margin of the cornea, while above it reaches a greater or less distance, according to the extent to which the cornea is uncovered, and ends in a horizontal border. This desiccation of the lowermost portion of the cornea occurs when the lids remain incompletely closed because the consciousness is clouded, as is the case in persons who, in severe diseases, lie unconscious for a long time. If such patients escape with their lives, they may have opaci- DISEASES OP THE COKNEA. I75 ties of the cornea in both eyes in consequence of keratitis e lagoph- thalmo, or they may even lose their eyes altogether. The treatment consists in taking care that the cornea shall be cov- ered by the lids. In this way the development of a keratitis is pre- vented by prophylaxis, or, if a keratitis already exists, the chief condi- tion is afEorded for its cure. AVe must accordingly initiate the proper treatment for the cure of the lagoph thalmus (see § 112), and in the meantime, until a cure has been accomplished, take pains to effect a perfect closure of the lids by means of a properly applied bandage. In order to do this, it is generally necessary to fasten the lids themselves together by strips of sticking plaster before the bandage is applied over the eye. In slight cases of lagophthalmus it is sufficient to keep the eye bandaged through the night only. But if the lagophthalmus is con- siderable, or if keratitis has already set in, the eye must be kept band- aged all the time. If the treatment is initiated early, the prognosis is good, inasmuch as the process comes to a standstill as soon as the desiccation of the cornea is arrested. ^. Keratomalacia. 38. Symptoms and Course. — Keratomalacia * occurs only in child- hood. The disease begins with night blindness (hemeralopia). This consists in the patient's visual power being perfectly good in bright daylight, but so very greatly reduced when the illumination is dimin- ished (e. g., in twilight) that>he is often no longer in a state to go about alone. In very small children who do not go about alone yet, this symptom naturally can not be made out. In such children, the first thing that strikes us is the dryness of the conjunctiva, which next de- velops, and which appears under the form of triangular xerotic spots on both sides of the cornea (see page 120). The conjunctiva in these spots is covered with a fine white substance like foam, and, as the lachrymal fluid can not moisten it, looks as if smeared with grease. The dryness extends rapidly over the rest of the conjunctiva and also over the cornea. The latter becomes dull, insensitive, and uniformly cloudy. Soon the cloudiness in the center of the cornea increases, a gray infil- trate forming there. This spreads rapidly, takes on the yellow color of pus, and terminates in the disintegration of the cornea— a disintegra- tion which, in bad cases, may- take place within a few hours. In the beginning the affected eye is not discolored ; afterward, when the cor- nea is already greatly involved, there appears about the latter a dusky venous injection. The lachrymal secretion is not increased, but rather diminished ; moreover, other symptoms of irritation, like photophobia and blepharospasm, are slight or are wanting altogether. The striking * Softening of the cornea, from [/c^pas, horn, and] /laKaKds, soft. 176 DISEASES OF THE EYE. contrast between the severity of the corneal affection and the insignifi- cance of the accompanying symptoms of irritation, together with the dryness of the eye, stamps the disease with quite a peculiar character. This affection usually attacks both eyes. Children suffering from keratomalacia show a disturbance of the general condition, which is generally pronounced even before the out- break of the eye trouble, and which afterward grows still greater. The children become strikingly apathetic, have diarrhoea alternating with constipation, become rapidly emaciated, and often ultimately die either from exhaustion or from a complicating bronchitis or pneumonia. The prognosis in very small children is bad, as in most cases they lose not only their eyes, but their lives as well. In somewhat older chil- dren the disease runs a less severe course, so that they escape with their lives and get off with smaller or larger cicatrices of the cornea ; indeed, the cornea itself may subsequently clear up once more (G-ouvea). Etiology. — Keratomalacia is the result of an insufficient nourish- ment of the cornea, which evidently is only one of the symptoms of a severe general disease. The real nature of the latter is indeed at pres- ent unknown to us, although there are various facts that do not permit us to doubt its existence. Thus the hemeralopia is nothing but the expression of the depressed nutrition of the retina. The latter still performs its functions well when it is acted upon by powerful impres- sions, such as images made by a strong light. But as soon as the brightness of the images falls below a certain limit, the images of the object are no longer able to excite the retinal elements, the energy of which has been depressed (torpor retinae). This condition is in har- mony with the general apathy exhibited by these patients. Another thing that points to a severe general disorder is the rapid decline of strength, which often develops in an altogether inexplicable fashion even in those cases in which the children at the beginning of the dis- ease were apparently healthy. Keratomalacia develops, as a rule, in consequence of enfeebling in- fluences affecting th6 children, and acting detrimentally upoQ their nutrition. Among these influences belong insufficient or unsuitable nourishment (rearing of children by hand), severe diseases like scarlet fever, measles, typhus, etc., and particularly hereditary syphilis. The disease occurs in Eussia much more frequently than with us, as there it attacks infants during and after the time of the great fast, because during this period the mothers lose their milk in consequence of fast- ing. For a similar reason it is frequently observed in Brazil among the badly nourished children of the negro slaves. Keratomalacia does not occur in adults, although the kind of hemeralopia that occurs with xerosis of the conjunctiva (see § 104), and which likewise occurs chiefly in poorly nourished persons, may be a milder form of the same disease. DISEASES OP THE COKNEA. 177 The chief task that treatment has to accomplish is to support the child's strength by means of fitting nourishment. In addition we must try to stimulate the vitality of the tissue of the cornea, a thing best performed by means of moist and warm compresses placed upon the eyes. If the apathetic little patients do not close their lids prop- erly, the cornese must be protected from desiccation by bandaging the eye. 5. Keratitis Neuroparalytica. 39. Symptoms. — In this affection, which occurs in consequence of paralysis of the trigeminus, the cornea becomes dull and slightly cloudy. Then the epithelium begins to be thrown off, first at the center, then more and more peripherally, until at length the entire cornea, with the exception of a marginal rim two to three millime- tres broad, is bared of its epithelium. This gives the cornea quite a peculiar appearance, such as is found in no other disease of it. In the meantime the cloudiness of the cornea also has increased. This is most marked in the center, and there is uniformly gray ; toward the margin it gradually decreases, and may be resolved by the magnifying glass into separate gray maculae. Subsequently the hue of the cloudi- ness becomes yellowish, hypopyon sets in, and ultimately the cornea in its center breaks down into pus. Thus a large ulcer forms, which cica- trizes with inclusion of the iris, and generally with flattening of the entire cornea. Not all cases, however, run so severe a course ; the keratitis may get well without the occurrence of any purulent disinte- gration of the cornea, although there always remain an opacity of con- siderable dimensions, and often, besides, a flattening of the cornea. The course of the disease is slow, and is characterized by the slight- ness of the associated symptoms of irritation. There is, indeed, marked ciliary injection but no laehrymation, since the secretion of the lachry- mal gland, due to reflex action, is diminished or abrogated. Owing to the coincident paralysis of the trigeminus, pain obviously is altogether absent. The prognosis is unfavorable, treatment having very little influence on the course of the disease, which, whether the formation of ulcers does or does not take place, leads, almost without exception, to the production of a dense opacity over the entire cornea, and hence to an almost complete annihilation of the visual power. Keratitis neuroparalytica has its cause in a paralysis of the tri- geminal nerve, which induces trophic disturbances in the cornea. The paralysis of the trigeminus also causes the simultaneous arrest of secretion of the lachrymal gland as well as the absence of pain. It is a matter of indifference whether the lesion which causes the paralysis of the trigeminus affects the trunk of the nerve or its nucleus of origin in the brain. 13 ITS DISEASES OF THE BYE. The treatment consists in the application of a bandage, warm com- presses, and atropine. Besides, we may try electricity, or, following NieJen's recommendation, strychnine (three to five milligrammes by hypodermic injection beneath the skin of the temple). The three affections of the cornea just described — keratitis e lagophthalmo, keratitis neuroparalytica, and keratomalacia — have been frequently confounded with each other. Thus the keratitis e lagophthalmo, which makes its appear- ance in patients during the death agony, has been regarded as a keratitis neuroparalytica, its cause being attributed to the depressed state of the nerv- ous influence. Conversely, some have explained keratitis neuroparalytica and keratomalacia as produced by desiccation of the cornea, and in this way have placed them in the same category with keratitis e lagophthalmo. Many authors deny absolutely the existence of keratitis neuroparalytica as an icde- pendent afllection. Hence this latter should be the first to receive careful con- sideration. The theory of keratitis neuroparalytica was founded by Magendie, who found that after section of the trigeminus in animals a keratitis made its appearance. He referred this to trophic disturbances. Snellen and Senftleben showed that the development of keratitis could be prevented by sewing to the eye a metallic capsule (the lid of a pipe). They hence concluded that the keratitis did not depend upon trophic disturbances, but was to be referred to traumatism ; for, as the animal has become destitute of sensation on the side operated upon, he strikes his eye against everything or rubs it against objects — e. g., against the walls of the cage in which he is confined. But inasmuch as simple mechanical injuries produce only attacks of cloudiness in the cornea, which rapidly pass off and never produce attacks of purulent keratitis like keratitis neuropara- lytica, the further assumption had to be made that the cornea, in cunsequence of the trigeminal paralysis, has a diminished power of resistance against exter- nal injuries. Then Peuer, by experiment, proved the inrorrectness of this ex- planation. After section of the trigeminus, the cornea can be injured in any way whatever beneath the metallic capsule sewed on in front of it, without anything but transient cloudiness of the cornea being produced. Hence, after section of the trigeminus, the cornea reacts toward external injuries just as it did before, and the cause of the efficacy of the metallic capsule must be sought for in something besides the prevention of traumatism. Peuer thought that he had found it in the fact that the metal capsule prevents the desiccation of the cornea. For in trigeminal paralysis the act of winking produced by reflex action is abolished; consequently the cornea becomes dry in its central, most exposed portion, and a delimiting suppuration develops about this dried and necrosed area. This sort of keratitis, which Feuer designated with the name of keratitis xerotica, is the alleged keratitis neuroparalytica. He was able to excite just the same sort of inflammation by producing lagophthalmus arti- ficially in animals with an intact trigeminus. For this purpose he sewed the two lids and the nictitating membrane so far back that they could no lono-er cover the cornea. Hence the efficacy of the metal capsule after section of the trigeminus consists, according to him, only in the fact that it prevents the desiccation of the cornea; for, as the animals strike the capsule ao-ainst the walls of the cage, they push the lids, to which it is fastened by sutures, in different directions over the cornea [and so moisten the eye]. Hence too DISEASES OF THE CORNEA. I79 Peuer was able to obtain the same eflfect with an open ring of cork, which he sewed in front of the eyes. Then Peuer applied his results to man, and demonstrated that the keratitis which is seen to develop in soporose patients is clinically and anatomically identical with that which is developed in ani- mals and men through imperfect covering of the cornea (keratitis e lagoph- thalmo). He went too far, however, in denying altogether the existence of a true keratitis neuroparalytica. Tliere is no doubt that the keratitis which is sometimes in man observed in connection with trigeminal paralysis is in solitary instances caused by desic- cation of the cornea, and thus is a keratitis e lagophthalmo. The desiccation is produced by the abolition of the regular movement of the lids and by the deficiency of the secretion of tears. In this way, for instance, are those cases to be explained in which paralysis of the oculo-motor nerve, and consequently incomplete ptosis, exist at the same time with paralysis of the trigeminus, and in which the cornea, as occurs in keratitis e lagophthalmo, is aflected only in its lowermost portions which are not covered and protected by the drooping upper lid. But there are cases, nevertheless, which present the characteristic picture of genuine keratitis neuroparalytica as above described— a picture which is altogether different from that of keratitis e lagophthalmo. Moreover, it is de- veloped in those cases of trigeminal paralysis in which the movements of the lids and the moistening of the cornea are perfectly normal, or in which, in consequence of complete ptosis, the cornea is entirely covered by the lid, and is thus protected from desiccation. Furthermore, since the application of a band- age, which is a sure preventive of keratitis e lagophthalmo, is of no avail against the development of a true keratitis neuroparalytica, the latter can not depend upon desiccation of the cornea. Again, the frequently repeated injuries to which the development of keratitis neuroparalytica in animals has been re- ferred can not be thought of as existing in the case of a human being who takes good care of his eyes. Hence we can only explain keratitis neuroparalytica by the assumption of a trophic disturbance. The fact that it does not occur in all cases of trigeminal paralysis is no evidence to the contrary, for the disease may have affected only the sensory and not the trophic fibers of the trigeminus. The trophic fibers, according to the views of different authors, arise from the sympathetic and attach themselves to the medial aspect of the trunk of the trigeminus. In fact, keratitis neuroparalytica has been obtained after sections of the trigeminus affecting only the innermost fibers of the nerve, although, in consequence of the sensory fibers being intact, the cornea and the lids have retained all their sensitiveness. We are therefore obliged to acknowledge the existence of a genuine keratitis neuroparalytica, and to make a sharp distinction between it and keratitis e lagophthalmo. The confounding of the three forms of keratitis— keratitis e lagophthalmo, keratitis neuroparalytica, and keratomalacia — with each other has been favored by the fact that they display various features in common.. Among these are the dryness which the eyes exhibit, and also the insignificance of the irritative symptoms in comparison with the severity of the keratitis, an insignificance shown in the absence of increased lachrymal secretion, of blepharospasm, and often also of pain. And yet the dryness of the eyes in these three forms of kera- titis is to be referred to very different causes. (a) In keratitis e lagophthalmo an actual desiccation of the cornea from evaporation exists. It affects only the exposed portion of the cornea, and may 180 DISEASES OF THE EYE. be relieved by closure of the lids. The desiccation in this case is the one cause of all the subsequent changes. (b) In keratomalacia the cornea is not actually dry, but only looks so, be- cause the lachrymal fluid does not adhere to its surface. This dry appearance is present even when the eye is swimming in tears or when it is kept constantly closed ; evidently, bandaging is of no effect against this sort of dryness. It is caused by a fatty metamorphosis of the epithelial cells, which consequently are not wetted by the lachrymal fluid. (c) In keratitis neuroparalytica there is neither real desiccation of the cor- nea, as in keratitis e lagophthalmo, nor a peculiar fatty condition of its surface, as in keratomalacia; on the contrary, the eye looks dry simply because, in spite of the marked inflammation of the cornea, the lachrymation, which we usually see under these circumstances in other cases, is absent. The secretion of the lachrymal gland is in fact diminished or altogether abrogated; nevertheless, the moistening of the eye is quite sufficient, as indeed it is after extirpation of the lachrymal gland. The absence of marked symptoms of irritation, which characterizes these three varieties of keratitis, is accounted for in the keratitis e lagophthalmo of very sick people and in keratomalacia by the general depression of strength, and in keratitis neuroparalytica by the insensitiveness of the eye. The irritative symp- toms, which in other cases are put in action through reflex impulses originating in the sensory nerves, are absent in the case of paralysis of the trigeminus. The three forms of keratitis are hence, in spite of their external similarity, entirely difllerent from each other, and can be readily differentiated by the clinical picture which they present. Keratitis e lagophthalmo occupies, as a rule, the lowermost part of the cornea. Keratomalacia begins in the center of the cornea, and is found only in children who are the subjects of a rapid decline of nutrition. Finally, keratitis neuroparalytica is characterized above all by the rapid exfoliation of epithelium over the whole extent of the cornea, and does not occur except in conjunction with a trigeminal paralysis which can be diagnosticated at once. The confusion between the three varieties of keratitis jnst described is fur- thermore favored by their nomenclature. The designation keratitis xerotica, chosen by Feuer for the keratitis of desiccation (keratitis e lagophthalmo), would be quite a good one if it did not lead to confusion with simple local xerosis of the cornea on the one hand and on the other with keratomalacia, in which xerosis of the conjunctiva and cornea likewise exists. And, as a matter of fact, some authors designate keratomalacia under the name of keratitis xerotica. In order to avoid this confusion, I have dropped the expression kera- titis xerotica altogether ; and as I do not wish to increase the number of epithets still further by the invention of a new name, I use the old expression keratitis e lagophthalmo for the keratitis of desiccation. B. Nonsuppurative Keratitis. (a) Superficial Forms. 40. 1. Pannus.— Pannus consists in the new formation of a tissue resembling granulations directly beneath the epithelium of the cornea. Pannus is to be looked upon as an affection of the conjunctival layer DISEASES OP THE CORNEA. 181 of the cornea (conjunctiva corneae, see page 40), and in every instance is simply one of the symptoms of a conjunctival disease — that is, either of conjunctivitis trachomatosa or conjunctivitis eczeraatosa. We hence make a distinction between pannus trachomatosus and pannus eczema- tosus. For further particulars, see under these two diseases of the con- junctiva. 2. Keratitis with the Formation of Vesicles.— Vesicles on the cor- nea are generally small, and are filled with a limpid liquid. Their an- terior wall is very frail, for it is formed simply by the epithelium of the cornea, which is lifted up from Bowman's membrane by serum. More rarely larger-sized blebs (bullEe) occur, the anterior wall of which gen- erally consists of a new-formed connective tissue in addition to the epi- thelium, and is hence more resistant. The small vesicles are ordinarily present in some numbers, while the large blebs generally occur singly. Violent symptoms of irritation, such as ciliary injection, lachrymation, photophobia, and more especially great pain, are usually present dur- ing the development of the vesicle. These, doubtless, are caused by the pulling upon the corneal nerves which pass into the epithelium, and which, in the process of formation of vesicles, are first stretched and finally torn in two. The irritative symptoms ordinarily disappear with the rupture of the vesicles. This occurs so quickly in the case of small vesicles that we generally do not get a sight of these themselves at all, but only of the subsequent small epithelial defects to the mar- gins of which the detached epithelium still adheres in loose shreds. The large blebs, on account of the greater firmness of the anterior wall, are of longer duration. They are not tightly distended, but form a lax, tremulous, somewhat dependent sac. After their rupture the lax anterior wall still lies upon the cornea, and can be readily made out by the way in which it can be displaced by movements of the lids. The sensitiveness of the cornea to touch is ordinarily diminished or entirely abrogated in cases in which there is a formation of vesicles. There are the following varieties of keratitis with the formation of vesicles : (a) Herpes * Fehrilis Cornem (Horner). — In febrile diseases, espe- cially of the respiratory organs (most frequently in epidemic influenza, next oftenest in bronchitis, pneumonia, ordinary influenza, etc.), less frequently in other febrile diseases, like typhus, intermittent fever, etc., small vesicles often make their appearance on the lips, the alae of the nose, the eyelids, the ears, etc.f At the same time an eruption of small transparent vesicles, which are associated with violent symptoms of irritation, may occur upon the cornea. These are scarcely the size of a pin's head, and are often disposed in rows or in groups. The vesi- cles very speedily rupture, leaving small abrasions, the floor of which * Prom iifnrew, to creep. f Hebra's herpes facialis. 182 DISEASES OP THE EYE. shows a faint opacity. Generally these abrasions soon heal, so that after two or three weeks the disease is over, without leaving any lasting opacity of the cornea. In severe, and especially in neglected, cases, however, large corneal ulcers, which not infrequently have a branching form (keratitis dendritica, see page 160), may develop from the small abrasions. There is no doubt that the vesicles upon the cornea are entirely analogous to those that develop upon the skin. Just as the latter are generally present only upon one side of the face, so also the affection of the eyes is usually unilateral in its development, and is, moreover, confined to the same side as the vesicles upon the face. With careful treatment the prognosis is good, as in that case the disease generally gets well without leaving any opacity. The treatment is purely symp- tomatic, being that which is indicated for corneal ulcers generally — that is, in the main, the employment of a protective bandage and of atropine. (/8) Herpes Zoster CornecB. — This is one of the symptoms of herpes zoster* ophthalmicus — that is, zoster which is localized in the region of distribution of the trigeminus (see the section on Diseases of the Lids, § 106). The cornea participates in the morbid process by form- ing small vesicles, which generally are arranged in groups and rupture speedily, as in the case of herpes febrilis. From the latter, herpes zos- ter is distinguished by running a considerably severer course, since the irritative symptoms persist after the rupture of the vesicles, the paren- chyma of the cornea at the spots where the vesicles were situated be- comes markedly opaque, and iritis occurs in conjunction with the keratitis. It takes a longer time for the opacities to disappear, nor is it always the case that they disappear completely. Naturally this is even more true of those cases in which large ulcers develop from the vesicles. The insensitiveness of the cornea to touch is especially pro- nounced in herpes zoster. Eeduction of the intra-ocular tension not infrequently exists so long as the inflammation is still recent. The prognosis of this variety of herpes, from what has Just been said, is less favorable than that of herpes febrilis ; the treatment is the same. (y) Keratitis Vesiculosa {ef Bullosa). — This variety occurs in eyes the cornea of which is more or less clouded and insensitive ; in eyes with a large corneal cicatrix, or eyes which have been rendered blind by irido-cyclitis, or by increase of tension. Either vesicles which are small and of short duration form with the accompaniment of violent inflam- matory symptoms upon the cornea (keratitis vesiculosa), or large tremu- lous bulls develop, which last for several days before they rupture (kera- titis bullosa). In all cases the vesicles show a great tendency to take * = girdle-eruption, from iaariii), girdle. We also speak of it as zona ophthal- DISEASES OF THE CORNEA. 183 on frequent recurrences, in each of which the irritative symptoms set in anew. The cause of the formation of vesicles appears to lie in the abnor- mal conditions of lymph circulation that are without doubt present in sucli eyes. By stasis of the lymph cedema of the cornea is produced ; the (Edematous fluid penetrates forward until it gets beneath the epi- thelium, and then lifts the latter up in places from Bowman's mem- brane. The prognosis is so far unfavorable in that the disease frequently recurs, on which account the affected eye, besides being useless for pur- poses of vision, is the source of constant discomfort to the patient. Treatment should aim at relieving the condition of irritation produced by the eruption of vesicles, and at preventing the recurrences. The former object is attained by opening the vesicles, the smaller ones being , pricked, and in the case of the larger ones the anterior wall being removed. When the vesicles recur frequently at the same spot we must try to modify the character of the base from which they develop by removal of the vesicle wall with the galvano-cautery, by superficial cauterization of the spot with a nitrate-of -silver solution, or by ablation of the most superficial layers of the cornea. Sometimes we do not put a stop to the recurrences until we have improved the conditions for the nutrition of the eye by means of an iridectomy ; we may even find our- selves compelled to perform enucleation of the diseased eye in order to give the patient ease. Apart from the forms above described, the formation of vesicles upon the cornea is further, in rare cases, observed under special conditions — e. g., as a re- sult of the action of various, and particularly of corrosive, substances upon the cornea, after burns, after a cataract operation beneath the bandage, etc. For the vesicles that usher in fresh recurrences of former erosions of the cornea, see § 43. Cases also occur in which, without known cause, there develop upon a perfectly sound cornea vesicles or bullae the formation of which we are inclined to attribute to nervous influences, as we do also in the case of herpes febrilis and herpes zoster. Cases of this- sort are usually characterized by periodical recurrence. I know one old lady who for twelve years suffered from occasional attacks of inflammation in her eyes, which otherwise were sound. The attack occurred once or twice a year, and afllected sometimes one eye, sometimes the other. It was associated with violent pain, great photophobia, and profuse lach- rymation. In the first days of the attack the only things found were cedema of the lids, great ciliary injection, and a cornea covered with minute elevations, as if it had been strewn with sand. Then a large transparent bulla developed upon the cornea, after the rupture of which the inflammatory symptoms rapidly abated and the epithelial defect healed without leaving a trace behind. A form of superficial keratitis which is related to herpes febrilis cornea?, but is not associated with the formation of vesicles, is l-erntitis ■pmictiita siiper- fciab's. It begins with the symptoms of an acute conjunctivitis. Changes in the cornea are observed either at the same time or not till some days or weeks afterward. These changes consist in the presence of minute gray spots 184 DISEASES OF THE EYE. which, as in the case of herpes febrilis, are often arranged in groups or in short rows (Fig. 54.) They are sometimes only ten to twenty in number, sometimes very abundant — upward of a hundred. They are either scattered irregularly over the cornea, or they are chiefly massed together in the central portion ; in every case, however, the marginal portions of the cornea are the part least covered by the spots. The spots lie in the most superficial layers of the cornea, which latter looks dull because the epithelium over the spots bulges out in the form of a nodule. The irrita- tive symptoms soon vanish, but the spots, as well as the punctate look of the corneal surface, generally remain for months almost unchanged, and then very gradually disappear. If the spots are not numerous, the sight remains undisturbed ; if, however, many spots are pres- ent, particularly in the center, the acuity of vision is iG. . .— ERATiTis reduced considerably. Keratitis punctata superficialis is found most frequently in young people, and affects sometimes one, sometimes both eyes. It often begins at the same time with a catarrh of the air passages, just as herpes febrilis corneoe does, but is distin- guished from the latter mainly by the absence of the formation of true vesicles. Hence, too, in keratitis punctata superficialis the superficial losses of substance, which develop from the vesicles in herpes, are wanting, and for the same reason the formation of ulcers in this variety of keratitis is observed only as a rare ex- ception. In various slight, superficial affections of the cornea, in which its epithelium is affected, we observe that fine filaments are formed, which adhere by one end pretty firmly to the surface of the cornea, while the other end, which is often swollen in a club shape, hangs down free. This phenomenon has been described as Jilamentary heratitia (Leber, TJhthoff, Fischer). The filaments are produced by a process of outgrowth from the epithelial cells of the cornea (Hess, Nuel). (J) Dee2} Forms of Non- Suppurative Keratitis. 41. These forms have as a common characteristic the develop- ment of an infiltrate in the middle and deep layers of the cornea, an infiltrate, however, which shows no tendency toward purulent dis- integration, but — generally not till after existing quite a while — disap- pears again by resorption. When this takes place, the cornea in favor- able cases clears up again completely, while in other cases opacities of a varying degree of intensity are left, and are sometimes even accom- panied by flattening of the cornea. In keeping with the deep posi- tion of the infiltrate in the cornea, the uveal tract, and especially the iris and ciliary body, are almost always implicated. S. Parenchymatous Keratitis* Symptoms and Course. — This afPection may run its course in two ways, according as it begins in the center or at the margins of the * Synonyms: keratitis interstitialis, keratitis prof unda, keratitis diffusa, uveitis anterior. DISEASES OP THE COEKEA. 185 cornea. If the disease invades the center of the cornea first, we see small, dim, gray maculae making their appearance in this situation, and lying in the middle and deep layers of the cornea ; the surface of the latter is lusterless and dull. The number of macule gradually increases, so that they keep extending farther and farther toward the margin ; but they are always massed most thickly in the center, where they frequently become confluent. Since even between the maculse the cornea is not clear, but shows- a fine diffuse cloudiness, the entire cornea may in severe cases get to look uniformly gray, like ground glass. As soon as the opacity of the cornea has advanced somewhat farther, vascularization begins by the penetration of vessels into the cornea from different spots upon the corneal circumference. We see the vascular trunks coming out from beneath the limbus, because — as opposed to the vessels in pannus — they arise from the deeply situated vessels of the adjacent sclera (Figs. 43 and 44). They branch in tufts, like a brush, in the deep layers of the cornea, and often appear quite in- distinct and of a dirty-red or grayish-red color, because they are cov- ered by the clouded superficial layers of the cornea. In those cases in which the disease begins at the margin of the cor- nea, the first thing that strikes us is that the latter has grown luster- less and clouded at some spot upon its margin. The cloudiness is deeply situated, and when regarded with the naked eye looks uniformly gray, but with the magnifying glass can generally be resolved into sepa- rate maculse or dim parallel streaks. Soon similar areas of cloudiness appear at other spots of the corneal margin, and then push their way forward concentrically from all sides toward the center of the cornea. Simultaneously with the appearance of the marginal opacities the cor- responding portions of the limbus become injected and the vessels of the corneal margin begin to grow out. The formation of vessels, as far as it originates in the network of marginal loops in the limbus, soon comes to an end, so that the limbus advances only a little way out upon the cornea, where it looks red and swollen (" epauletlike " swelling of the limbus). On the other hand, the deep vessels, which come out from beneath the limbus, grow farther and farther into the cornea, and follow closely upon the opacity which advances in front of them ; it looks as if they were pushing the opacity before them. These vessels have, as in the case of those of the first form, the char- acters of deeply situated vessels, shown by their penicillate branching and by their dull, dead, grayish-red hue. When parenchymatous keratitis has attained its acme, the cornea is often so opaque that we scarcely recognize the iris through it. At the same time it loses its luster completely, so that it looks as though smeared with grease (with the magnifying glass we recognize numer- ous minute elevations of the epithelium, which make the surface of the cornea rough, as if made of fine shagreen). Sight is so reduced 186 DISJ5ASBS OF THE EYE. that the patient can only count fingers held very close to him, or, still worse, can only recognize the movement of the hand before his eye. Now gradually the process of recovery begins, starting from the mar- gin, virhere the cornea first becomes transparent again, while at the same time the vessels grow constantly fewer and fewer. The center of the cornea remains opaque the longest, but finally clears up, too, until only a fine diffuse cloudiness remains, which causes but little impairment of sight. This cloudiness, together with a few very minute blood-vessels which are only visible with the magnifying glass, can still be made out years afterward, and are certain signs of the previous existence of a parenchymatous keratitis. Parenchymatous keratitis always runs a chronic course. The in- flammatory symptoms keep on increasing for one or two months, until the disease has reached its acme. Then the irritative symptoms very soon abate, and the process of clearing up of the cornea makes at first rapid progress. Afterward, however, it goes on more slowly again, and the center of the cornea in particular remains for a long time opaque, so that sight is not restored until late in the disease. It takes from half a year to a year, or even more, for the cornea to acquire the full degree of transparency which it is possible for it to assume with an in- flammation of the given intensity. All the cases do not run their course in the way described. There are, for example, many lighter cases in which the changes do not go far, and which hence, too, are completed in a shorter time. Thus the process may go no further than the formation of a few maculee, which gradually disappear again without the associated inflammatory symp- toms being at any time marked. If the opacity begins at the margin of the cornea, it often remains confined to that section of it from which it originally started. In that case, if it pushes its way farther from the margin toward the center, only a sector, and not the entire cornea, is rendered opaque. Conversely there are also — luckily not often — very severe cases in which dense opacities remain as a permanency. Again, owing to the inflammatory infiltration, softening of the cornea may be produced, so that the latter gives way before the intra-ocular pressure and keratectasia develops ; in this case also the cornea remains permanently opaque, and to quite a marked degree. The worst cases are those in which, by subsequent shrinking of the exudate, the cornea becomes flattened, densely opaque, and of a tendinous appearance, in which case the sight is nearly or quite lost. _ Just as great variations exist in regard to the density and extent of the infiltration, so they do also in regard to the vascularization. In many cases the cornea is so abundantly vascularized that it looks like a red cloth; in others, on the contrary, it is almost devoid of vessels, and is like white ground glass. Lying between these extremes are numer- ous cases in which vessels develop from only single spots upon the cor- DISEASES OP THE COENEA. 187 neal margin, so that simply a sector of the cornea looks red, or so that only single tufts of vessels are discoverable. Hence we may distinguish between a vascular and a non- vascular form, according to the relation? of the vessels. It must be remarked, however, that even in the non- vascular form one 'or two vessels can generally be made out with the aid of the magnifying glass. When we consider how the cases vary both in respect to the opacity and to vascularization, we comprehend why parenchymatous keratitis should present a very varying clinical picture, and hence often offer diffi- culties in the way of diagnosis for the beginner. But we shall generally be able to make the diagnosis with certainty if we hold fast to those symptoms which are common to all the cases — namely, the deep situa- tion of the opacity and of the vessels, the typical increase in the in- filtration up to a certain, usually considerable, degree, and finally the absence of purulent disintegration, so that the formation of ulcers never takes place. Parenchymatous keratitis is accompanied by irritative symptoms, such as pain, photophobia, and lachrymation. These are sometimes very slight, sometimes violent; in general we may say that they are more pronounced, the greater the amount of vascularization with which the keratitis is associated. Furthermore, parenchymatous keratitis is almost always complicated with inflammation of the uveal tract. In the lightest cases there is merely hypereemia of the iris, which makes itself apparent by the failure, complete or nearly so, of the pupil to dilate under atropine. In severe cases there is iritis, which may lead to the formation of posterior synechia, the formation of deposits upon the posterior surface of the cornea, and seclusion and occlusion of the pupil. In particularly bad cases a plastic irido-cyclitis develops, which terminates in flattening of the cornea, or even in atrophy of the eyeball. Parenchymatous keratitis generally attacks both eyes, and more frequently both in succession than both at once. Sometimes there is even an interval of several years between the involvement of the two eyes. Kecurrences of the disease take place, but are not common. T\\(i prognosis of the disease, from what has been said, is unfavor- able as regards its duration, inasmuch as it drags on for months and years, especially if the two eyes are successively attacked. On the other hand, the prognosis in regard to the ultimate outcome must be put down as good, because in by far the greater number of the cases a good, or at least serviceable, degree of sight comes back. By holding up this prospect of recovery the physician must keep up the courage of his pa- tient, who, because of the slow progress of the disease, is very apt to lose all hope of a restoration of his sight. Etiology.— Parenchymatous keratitis is a disease of youth, appear- ing, as a rule, between the sixth and the twentieth year of life. It is only the exception that persons before or after this age (sometimes 188 DISEASES OF THE EYE. even after the thirtieth year) are attacked. The female sex suffers from it more frequently than the male. The ordinary cause of the disease is syphilis, and especially hereditary syphilis. To prove the existence of hereditary syphilis from the history of the case directly — i. e., by getting the father or mother to confess to syphilis — is often a difficult thing to do. Besides, in most cases it is not at all necessary, since hereditary syphilis can generally be recognized vfith sufficient certainty from a series of symptoms. In that case, we abstain from questioning the parents in regard to this matter, the more so since it would be a severe reproach to them to have to recognize in their own persons the cause of their children's illness. On the other hand, it is a good thing to determine by questioning whether many children have died in the family (the mortality of the children of syphilitic parents amounts, on an average, to fifty per cent), whether premature labors, and especially those in which the fostus was dead or putrefied, have not occurred, etc. The symptoms of hereditary syphilis which patients with paren- chymatous keratitis frequently exhibit are as follows : 1. A peculiar formation of the face and cranium. The upper jaws are markedly flat, and the bridge of the nose low and often sunken in. Not infrequently there exists ozsena or blennorrhoea of the lachrymal sac, the latter in consequence of the changes in the nose. The frontal eminences are very prominent. The intelligence of these patients is often abnormal, they being either precocious, or, on the other hand, backward in the mental development. 2. The incisor teeth are abnormally shaped (Hutchinson), so that, instead of a straight edge, they show a semilunar indentation. This change exists only in the teeth of the second dentition, and then most frequently in the upper central incisor teeth. The incisor teeth are often also stunted in their growth as a whole, so that they are either too small or are altogether wanting. 3. At the angles of the mouth we may find fine linear cicatrices as relics of former rhagades ; so also cicatrices in the buccal and pharyn- geal cavities (especially on the hard and soft palate) point to the exist- ence of antecedent syphilitic ulcerations. 4. Numerous enlarged lymphatic glands can be made out, especially upon the neck. These are small, hard, painless, and with no tendency toward ulceration, by which characters they are distinguished from the lymph glands of scrofulous subjects, which are large and soft, and readily undergo caseation. 5. Swellings of the periosteum (tophi), which are hard and are but little or not at all painful, occur on the long bones. They are most frequently and most easily found upon the anterior border of the tibia. Sometimes a serous inflammation of the knee joint (hydrops genu) is present ; caries is rare. DISEASES OE THE CORNEA. Igg 6. We frequently find hardness of hearing, which, with the outbreak of the keratitis, sometimes increases to absolute deafness. It is important to look for all of these symptoms, for any one of them by itself is not to be looked upon as conclusive evidence of the existence of hereditary syphilis ; and, on the other hand, we ought not to expect to find all the changes above given distinctly marked in the same individual at once. The more carefully we make our investiga- tion, the greater is the number of these symptoms that we are able to establish ; so that we arrive at the conviction that by far the greatest number of cases of parenchymatous keratitis are to be referred to hereditary syphilis. In very rare cases this form of keratitis is also ob- served in acquired syphilis. A few cases may depend upon scrofula, while in many no cause at all that we can be sure of is discoverable to account for the eye disease. Treatment. — Local treatment during the period of progression con- sists in combating the inflammation by protecting the eyes from light and by instilling atropine, which latter counteracts the complications arising from the iris. Moist warm compresses often ameliorate the symptoms of irritation, and accelerate somewhat the progress of the dis- ease. In the regressive period, the thing to do is to secure as thorough- going a clearing up of the cornea as possible. For this purpose the well-known irritant remedies — like calomel, tincture of opium, yellow- precipitate ointment, hot steam, etc. — are indicated (see page 157). These, however, should only be brought into application when, on making cautious tests, the eye is found to bear them well — i. e., does not through their use fall into a state of renewed irritation. It is ad- visable to keep on with these remedies, interchanging them frequently, for a very long time — for months or years. If ectasis of the cornea threatens, it is to be combated by a pressure bandage, which, if neces- sary, can be combined with repeated paracentesis of the cornea. General treatment in those cases in which hereditary syphilis is the cause must be directed against the latter. Mercurial treatment, which is of such marked service in acquired syphilis, is here ordinarily less efficient. Since it is at the same time a very drastic method of treatment, it is advisable to apply it in the severe cases only. In adults we had best select the treatment by inunction. If from the circum- stances of the case this can not be done, we may give mercury inter- nally or still better in the form of hypodermic injection. A hypo- dermic syringeful of a one-per-cent sublimate solution (to which from one to five per cent of sodium chloride is added) may be injected once a day or once every other day into the glutei. In children the inter- nal administration of corrosive sublimate is preferable. We give pills of one milligramme, beginning with one a day, and increasing the dose to from six to ten pills a day, according to the age. In doing this we must be mindful to pay careful attention to the condition of the mouth. 190 DISEASES OP THE BYE. in order to avoid salivation. In the lighter cases of parenchymatous keratitis we prefer, in place of mercury, a simple corroborative treat- ment with the simultaneous employment of remedies containing iodine (cod-liver oil with iodine, iodide of iron, and minei-al waters contain- ing iodine, the latter especially as a form of after treatment). Unfor- tunately, we must say that, in general, treatment is pretty nearly pow- erless against this disease. Parenchymatous keratitis in many cases, even under the most careful treatment, runs a course that is not essen- tially different from what would have been the case without any treat- ment ; not infrequently we see the disease while under treatment break out in the other eye, without our being able to prevent the opacity from spreading gradually over the entire cornea in this eye also. The chief use of treatment consists in its combating the complications aris- ing from the uvea, and also in securing a more rapid and more perfect clearing up of the corneal opacities during the period of regression. Up to the present time it has been possible to make an anatomical examina- tion of an eye affected with parenchymatous keratitis in a few cases only. The examination shows dense infiltration of the most posterior layers of the cornea, so that they sometimes appear as if transformed into granulating tissue (i, Fig. 55) ; moreover, in the posterior and middle layers of the section we see numer- ous newly formed blood-vessels (Fig. 55, g). The infiltration at the margin of the cornea is continued into the ligamentum pectinatum, the iris, and the ciliary body. In one case (in a fourteen-year-old boy) I found this region infil- trated with numerous nodules which were composed of small cells and which had a certain resemblance to tubercles, although it was not possible for me to demonstrate the presence of tubercle bacilli or of other micro-organisms. In- stances of similar nodule formation have since then been observed by others, and it has hence been conjectured that parenchymatous keratitis may be caused by tuberculosis more often than has hitherto been supposed. According to the results of anatomical as well as clinical examination, there- fore, parenchymatous keratitis is situated in the most posterior layers of the cornea, which, according to the teachings of embryology, are to be classed with the uvea (see page 133). It should not, therefore, excite our astonishment if the uvea proper is also always implicated. To be sure, the participation of the uvea in the inflammation is not by any means equally pronounced in all cases. Minute deposits, which are discovered in making a careful examination of the cornea with the magnifying glass at the time when the opacity is resolving, are scarcely ever wanting. Besides these, the most frequently occurring complica- tions are posterior synechiije and also chorioiditic foci ; hypopyon, on the other hand, is extremely rare. In many cases the part that the uvea takes is so slight as not to be clinically demonstrable ; in other cases, on the contrary, it is so very prominent, as compared with the process in the cornea, that what we have before us is really an irido-cyclitis— the implication of the cornea being evi- denced only by the presence of a few spots of opacity in its deep layers. Thus there is a continuous series of intermediate forms between typical par- enchymatous keratitis and iridocyclitis e lue hereditaria. Among the more frequently occurring variations in the clinical picture of parenchymatous keratitis the following may be mentioned : In that form which DISEASES OP THE CORNEA. 191 begins with macula) in the central portions of the cornea it not infrequently happens that the maculae at a certain distance from the cornea are placed par- ticularly close together, and thus form a very opaque ring, which still remains visible as a gray circle even when the separate macula! have coalesced into a continuous mass of cloudiness (hence described by Vossius in brief as lera- titis centralis annula/ris). Allied to these cases are those in which the cen- tral part of the cornea becomes particularly opaque through the confluence of r r Fro. 55. — Cross section through a Cornea with Parenchymatous Keratitis. Magnified 100 x 1. (After a preparation of I>r. Nordenson.) The stroma, S, of the cornea shows an infiltration, which begins in the middle layers, and keeps on increasing more and more posteriorly, so that the deepest layers, i, have assumed the aspect of a granulating tissue. On account of the inequality in the degree of thickening of these layers, Descemet's membrane, I), is undulated ; upon its endothelium there are depos- ited in places small accumulations of round cells, r. In the middle and deep layers of the cornea we see the transverse and longitudinal sections of newly formed blood-vessels, devised specially for itself. In injuries produced by chips of iron, the magnet is employed. Forms of apparatus have been constructed to determine in doubtful cases whether a piece of iron is present in the eye at all. In these the injured eye is brought as close as possible to a very sensitive magnetic needle (astatic needle of L6on Gerard, sideroscope of Asmus) which undergoes deflection if there is a chip of iron present in the eye. By ascertaining at what point of the surface of the eyeball this deflection is the greatest, we can determine approximately the situation, of the iron. Much more frequently the magnet is employed for removing the foreign body. The extraction of a chip of iron from the vitreous by means of a bar magnet introduced tlirough an incision on the sclera was first performed by MacKeown (1874). Hirschberg constructed the first available electro-magnet, wliich is the form now commonly employed. About a rod of soft iron is wound a spiral coil of copper wire, not too thin, the two ends of which are connected with a powerful galvanic element. The ends of the iron rod, which project somewhat beyond the spiral, are a little bent and end in a blunt point, adapted for introduction into the interior of the eye. For this latter purpose we enter either through the wound itself, in case this is large enough and is still open, or we make an incision in a suitable situation in the cornea or sclera, according to the location of the foreign body. Recently very powerful electro-magnets have been used (Haab, Schloesser). These are not introduced into the eye, but are merely applied to it exteriorly, as they are able to attract even small frag- ments of iron when at some distance from them. It is not often that the point of entry of the iron chip is a proper place to apply the magnet to, in order to extract the fragment from the eye. Generally, it is better to place the tip of the magnet against the center of the cornea, so as to bring the fragment through the pupil and into the anterior chamber, from which it may then be removed by an incision made at the margin of the cornea. The large have the follow- ing advantages over the small magnets: (1) It is not necessary to make a 244 DISEASES OF THE EYE. wound in the sclera ; (3) the situation of the fragment need not be known pre- cisely ; (3) even very small fragments can be removed in this way. III. Ectasia of the Sclera. (a) Partial Ectasia. 55. Partial ectasia of the sclera is represented by a circumscribed protrusion taking the form of a dark prominence or swelling. The sclera at this spot is thinned, so as to be readily dimpled with the point of a sound ; in consequence of the thinning, the chorioidal pigment appears through it, and imparts to the ectasia a dark, slate-gray, or bluish-black color. By means of focal illumination, light can often be made to pass through the sclera at the ectatic spot, and the coating of pigment on its inner surface can be seen through it. According to the situation of the ectasia, various forms of it are distinguished — namely : 1. Anterio?- Ectasim (anterior scleral staphylomata). — These occupy the portion of the sclera adjoining the cornea (Figs. 67 and 68). They appear in the beginning under the form of small, dark spots, which afterward become larger and bulge out. When several lie close together they become confluent, forming a large swelling which surrounds the cornea like an arch or ring. This swelling at various points is con- stricted in a radial direction by the stronger, less distended fibers of the sclera, so that in a small way it resembles the large intestine with its sacculations. The limbus, under the form of a somewhat depressed gray line, marks the boundary between the ectasia and the cornea. When the latter is also opaque and ectatic, the sharp line of demarca- tion between scleral and corneal ectasis is often lost, and both ectasise unite to form a single protuberance occupying the anterior segment of the eyeball. It often happens that an anterior scleral staphyloma exists, or, at all events, has its chief development, on one side only. Then the base of the cornea at this side is pushed forward, so that the entire cornea gets to lie obliquely. If, for instance, the scleral staphy- loma occurs on the inner side, the cornea looks outward instead of straight forward (Fig. 68, h). 2. Equatorial Ectasim (equatorial staphylomata).— These are dark prominences in the region of the equator of the eyeball. They can be seen only when the eyeball is turned strongly toward the side opposite the staphyloma. They occur at either one or more spots upon the equator, but never surround the entire eyeball like a ring, as is fre- quently the case with anterior scleral staphylomata. 3. Posterior Ectasice.—These occupy the posterior segment of the eyeball, and can not, therefore, be seen in the living eye. In respect to origin and significance, they are essentially distinct from anterior and equatorial staphylomata of the sclera. There are two kinds of posterior DISEASES OP THE SCLERA. 245 scleral ectasiis : a. The staphyloma posticum Scarpm. This consists in a thinning and protrusion of the sclera at the posterior pole of the eye to the outer side of the optic-nerve entrance. If the ectasia takes ou greater dimensions, the optic nerve is also involvedin it (Fig. 221). This form of ectasia, as Arlt was the first to discover, is the most frequent cause of short-sightedness, because owibg to the recession of the sclera the eyeball undergoes an elongation of its sagittal axis (axial myopia). The diagnosis of a posterior staphyloma can be made in the living eye only by demonstrating the existence of a high degree of myopia and of the accompanying changes in the opthalmoscopic picture (§ 77). /3. Posterior scleral protrusioti of Amman. This does not, like posterior staphyloma, lie just at the posterior pole, but below it. Contrary to the case of the other ectasite of the sclera, it is not acquired but congenital, being formed in consequence of an incomplete closure of the foetal ophthalmic cleft. It is found simultaneously with the formation of a fissure (coloboma) in the chorioid and frequently, also, with coloboma of the iris (see §§ 76 and 80). Acquired ectasise of the sclera are designated under the name of staphylomata of the sclera, as has been done in the preceding lines, but the expression staphyloma is not applied to the congenital scleral pro- trusion of Ammon. (h) Total Ectasia of the Sclera. This consists in a uniform dilatation of the entire sclera, so that the eyeball is enlarged in toto. The sclera is everywhere thinned and the chorioidal pigment shows through it, so that it has a bluish-white appear- ance. Total ectasia can develop only in youth when the sclera is still everywhere yielding ; the sclera of adults is so rigid that it can protrude only at certain weaker spots, and hence it admits of only partial ectasise. Total ectasia occurs most frequently at the same time with staphyloma of the cornea or with anterior scleral staphyloma. By the combina- tion of these two kinds of ectasia a very extraordinary enlargement of the eyeball sometimes develops. Much more rarely a second, pure form of scleral ectasia is observed, in which the eye shows simply a uniform enlargement in all its dimensions — an enlargement in which the cornea also participates (megalocornea). This condition is charac- terized as hydrophthalmus or buphthalmus (/3o{)s, ox, on account of the resemblance to the large eyes of oxen). Hydrophthalmus is either con- genital or is acquired in early childhood, and is probably analogous to the glaucoma of adults, under which disease, therefore, hydrophthal- mus will be treated of in detail (see § 83). Etiology. — Every ectasia of the sclera is the result of a dispropor- tion between the intra-ocular pressure and the resistance of the sclera. Either the tension of the eye is pathologically heightened or the tenac- ity of the sclera is diminished. The former is much the more fre- 246 DISEASES OP THE EYE. quent cause of scleral ectasise (if the posterior ectasias are excepted). Scleral ectasiae develop slowly, and the disproportion between the ten- sion of the eye and the resistance of the sclera must persist for a pretty long time before it can make the sclera become ectatic. (a) The result of elevation of the intra-ocular tension is that every square millimetre of the interior surface of the sclera has to bear the same increase of pressure. If the sclera possessed the same constitu- tion throughout it would, in case it yielded to the pressure at all, ex- pand in a perfectly uniform fashion. But some portions of the sclera are constructed less solidly than others, and these give way first to the increased pressure. These less tenacious spots are those in which the sclera has nerves or vessels passing through it into the interior of the eye, and in which, therefore, it is perforated and thinned. Chief among these places is the lamina cribrosa, and next those portions of the sclera where the venae vorticosae and the anterior ciliary vessels perforate it. At the site of the lamina cribrosa the sclera is reduced to a thin mem- brane, which is riddled with holes like a sieve, and which, under in- creased pressure, bulges out backward. This bulging, however, is not counted among the staphylomata of the sclera, but is designated as an excavation of the optic nerve, because the head of the optic nerve recedes simultaneously with the lamina cribrosa (§ 81). Equatorial staphylomata develop at those spots where the venae vorticosaB perforate the sclera and anterior scleral staphylomata at the spots where the anterior ciliary vessels are transmitted. The other, more resistant sec- tions of the sclera remain unchanged, even under increased intra-oeu- lar pressure ; it is only in children, in whom the sclera is capable of expanding as a whole, that total ectasia develops. The most frequent causes of the elevation of intra-ocular pressure are glaucoma, seclusio pupillae, and ectatic cicatrices of the cornea. In glaucoma, in which the venae vorticosae are the main seat of congestion and inflammation, equatorial staphylomata generally de- velop ; seclusio pupillae and staphylomata of the cornea, on the con- trary, in which the inflammation expends itself upon the most an- terior sections of the eyeball, mostly induce anterior ectasise of the sclera. < {I) The result of diminished resistance of the sclera may be that the latter is unable any longer to withstand even the normal intra- ocular pressure. Diminished resistance develops in consequence of inflammations of the sclera, and hence occurs in the deep form of scleritis, which leads to anterior scleral ectasiae (page 239) ; it also occurs when tumors (malignant new growths, gummy or tuberculous nodules) develop in or beneath the sclera. Injuries of the sclera also diminish its tenacity, and hence the cicatrices after penetrating wounds (and especially after ruptures) of the sclera very frequently become ectatic. Scleral ectasiae arising in this way lead subsequent- DISEASES OP THE SCLERA. 24T ly to elevation of the intra-ocular pressure, which then, however, must be regarded not as the cause, but as the result of ectasis, even though it does contribute to make the latter still larger. Here, then, the same process that occurs in ectasise of the cornea (page 215) is repeated. Posterior scleral ectasise are likewise referred to a diminution in the resistance of the sclera. With regard to the development of staphyloma posticum, the cause of it is assumed to be a congenital weakness of the sclera in its posterior portion. With respect to Ani- mon's scleral protrusion, the idea is held that the foetal ophthalmic cleft is filled up with a sort of intermediary tissue which does not possess the firm texture of the normal sclera, and hence gives way be- fore the ocular pressure. Consequences of Scleral Ectasise. — In anterior and equatorial staphy- lomata of the sclera the sight is at length completely destroyed through rise of tension. If the ectasia does not come to a stop, the enlargement of the eyeball keeps growing greater and greater. The eyeball projects far beyond the palpebral fissure, can be covered but incompletely by the lids, and is extremely disfiguring. Conjunctival catarrh, lachryma- tion, and blepharospasm develop as a result of the mechanical irrita- tion, and not infrequently the lower lid is pushed so far out by the enlarged eyeball as to be everted (ectropion). Finally, some light injury suffices to cause the rupture of the staphyloma at a particularly thinned-out spot. The greater part of the liquefied, vitreous is evacu- ated, and in consequence a violent haemorrhage may take place, and the eye may undergo destruction with the symptoms of panophthal- mitis. Staphyloma posticum, if it enlarges, causes a considerable increase in the short-sightedness, without, however, inducing elevation of ten- sion and the other deleterious consequences of anterior and equatorial staphylomata. The scleral protrusion of Ammon remains stationary and entails no injurious consequences. Treatment. — It is only anterior and equatorial, not posterior, ectasias of the sclera that are amenable to treatment. In the former, which, in the great majority of cases, have developed in consequence of an increase of tension, the main indication is iridectomy, provided that it is still technically practicable. Inasmuch as this operation dimin- ishes the intra-ocular pressure, it puts a stop to the further enlarge- ment of the scleral ectasiae (and in especially favorable cases even causes diminution in the size of an ectasia already existing), and likewise pre- serves the sight, so far as it still exists, from total destruction. If, as indeed is generally the case, iridectomy is on technical grounds no longer practicable, there is nothing else left to do but enucleation, in case the eye distresses the patient by its size, its painfulness, or the disfigurement it causes. 248 DISEASES OP THE EYE. The anatomical structure of scleral staphyloma is essentially different from that of staphyloma of the cornea. While the latter consists of cicatricial tissue which replaces the cornea that has been destroyed, a scleral staphyloma is formed of the sclera itself, which has not ceased to exist at the site of the ectasis, but is simply thinned, so that often it is no thicker than a sheet of paper. In posterior staphyloma the thinning is uniform ; in anterior and equatorial staphylomata we often find that the thinning is not uniform, and commences suddenly, owing to the abrupt disappearance of the inner layers of the sclera at the margin of the ectasis. The sclera then in the spot where it bulges looks as if it had been gnawed into from the inner side, and thus deprived of its innermost layers. Prob- ably this is owing to the fact that the innermost layers of fibers of the sclera, in consequence of the great stretching to which they are exposed, first rupture at some spot and then gradually separate from each other (Czermak and Bim- bauher). The uvea is always solidly adherent to the inner surface of the ectasia, and is here so atrophic that scarcely anything is left of it but its pigment layer, which forms the dark coating of this inner surface. Dissection of ectatic eyeballs shows that anterior scleral staphyloma may be of two kinds — ciliary or intercalary staphyloma. The former (Fig. 67) belongs Fig. 67.— Staphyloma Ciliare. (After Pagenstecher.) The eye is bisected horizontally. Surrounding the cornea there is an ectasia, o, of the sclera, which attains its greatest breadth at the tetnporal side, t ; and on the nasal side, n, is nar- rower and less prominent, for which reason the cornea appears displaced toward the nasal side. The inner surface of the ectasia is coated with the elongated cihary processes • the iris is invisible because it is pressed against the posterior surface of the cornea which hence looks pigmented in black. The retina and chorioid have been to some extent separated from their bed b.y the dissection ; in the retina, groups of punctate haemorrhages b are observ- able. The head of the optic nerve, o, shows a deep excavation due to pressure.' Fig. 68.— Staphyloma Intebcalaee. The eyeball is horizontally bisected and is drawn of somewhat more than the natural size The ectasia, s, of the sclera is interposed on the nasal side, n. between the cihary body, c, and the cornea, h, so that the latter is displaced toward the temporal side. The inner surface of the ecta-sia is covered with pigment, representing the remains of the root of the iris which has become adherent to the thinned sclera : this pigment, in consequence of being spread over so large a surface, shows numerous gaps. Toward the outer side the ectasia con- stantly diminishes in breadth, so that, at the spot where the temporal wall of the eye- ball, t has been cut through, nothing but a very narrow interspace is observable between the cihary body and the ins, a condition due to that agglutination of the root of the iris to the sclera which characterizes an increase of tension. In the bisected optic nerve, the nor- mal conical contraction of the intra-scleral section, i, can be recognized : and in the retina can be seen the fovea centralis, /, and the expansion of the retinal vessels. to that part of the sclera, the inner surface of which is coated by the ciliary body; the latter (Pigs, 68, 69), on the other hand, develops in that narrow portion of the sclera which is situated in front of the ciliary body, between it and the margin of the cornea; for the anterior border of the ciliary body, and hence, DISEASES OF THE SCLERA. 249 too, the root of the iris, as it springs from the ciliary body, do not correspond precisely to the sclero-corneal junction, but lie somewhat behind it — that is, the most anterior portion of the sclera, which lies in front of the root of the iris, be- longs to the anterior chamber. But, although it is just in this portion that an intercalary staphyloma develops, the iris does not lie behind the latter but in Fig. 69.— Intercalary Staphyloma. Magnified 4x1. The figure represents a vertical section through the anterior half of the ectatic eyeball, which presents a great resemblance to the eye shown in Fig. 68, except that the most marked ectasia in the present case is situated above the cornea. The limits of the cornea are marked by the linibus I and Ij. At Z may be seen how the root of the iris is apphed to the sclera ; and the beginning of a process of thinning in the sclera can be made out. while on the other side of the eye there is a fully developed mtercalary staphyloma, which extends frorn a to 6, and which in the living eye formed a dark translucent prominence. In the region of the staphyloma the sclera is reduced to half its normal thickness, and its inner surface is covered with a thin pisment coating representing the rnmains of the iris. The iris is adherent to the sclera from the ciliary body, a, to the anterior border, b, of the ectasia. The ciliary processes, owing to atrophy, are flatter than normal. front of it, just as in the case of ciliary staphyloma. This comes to pass in the following way : The formation of the ectasia is preceded by increase of tension, which causes the most peripheral portion of the iris to be pressed forward and to become united with the sclera (see § 84 and Figs. 118 and 119). Hence that pait of the iris lying free in the anterior chamber is given off from the sclera at a point farther forward tlian usual. Looked at with the naked eye, it seems as if the insertion of the iris had been pushed forward, up to the scloro-corneal junc- tion or beyond it. Now, an intercalary staphyloma develops precisely in that region of the sclera which is united with the periphery of the iris — i. e., at I in Fig. 69, where the beginning of such an ectasia may be made out from the fact that just in front of the point where the iris is given off the innermost lamellES of the sclera have separated and the iris has been pushed into the gap. Hence the ectasia always lies between the real origin of the iris at the anterior border of the ciliary body and its apparent origin at the spot where the portion of the iris that is yet free commences; and does so still even when it gets to be as large as represented on the left side of Fig. 69 (between a and h). The inner surface of an intercalary staphyloma is coated with a layer of pigment, which is nothing but the completely atrophic root of the iris that has become united to the sclera. In an eyeball which has not been dissected, the distinction between a ciliary and an intercalary staphyloma is more difficult to effect than in an anatomical specimen, but may still be made from the following diagnostic points: In intercalary staphyloma the anterior ciliary vessels are seen emerging from the 250 DISEASES OP THE EYE. sclera at the posterior border of the ectasia, in ciliary staphyloma at its anterior border. A thin ciliary staphyloma usually transmits light, and so admits of our recognizing the elongated ciliary processes as black strise on its inner surface (c, Fig. 67). Ectasis of the sclera usually entails still further changes in the interior of the eyeball. In consequence of the enlargement of the ring formed by the ciliary body, the iris becomes stretched and atrophic, and may even in places be sepa- rated from its insertion (spontaneous iridodialysis). The same is true of the zonule of Zinn, which, through atrophy, gets to be so deficient that the lens be- comes tremulous or even undergoes luxation. The ciliary body, chorioid, retina, and optic nerve become atrophic ; the latter generally presents a deep excava- tion due to the increase of tension (o, Fig. 67). TJlcebs akd Tumors of the Sclera. — The sclera is not very apt to become inflamed, and still less are the products of its inflammation apt to undergo purulent disintegration; thus, for example, ulceration of scleritic nodules is never observed. Ulcers which originate in the adjacent part of the cornea are always arrested as soon as they reach the sclera; nor are ulcers of the con- junctiva any more likely to extend to the sclera beneath them. Hence ulcers in the sclera are among the greatest of rarities. They originate from injuries associated with infection and also from the disintegration of new growths (gum- mata, tuberculous and leprous nodules, malignant new growths). New growths, too, occurring primarily in the sclera are extremely rare; although, of course, tumors originating in other parts of the eye do pass over to the sclera. Fibromata, sarcomata, and osteomata are the primary tumors that have been observed in the sclera. CHAPTER IV. ANATOMY AND PHYSIOLOGY OF THE UVEA, EMBRYOLOGY OF THE EYE. I. Anatomy. 56. If we carefully remove the sclera and cornea from an eyeball, we have presented to us the iris, ciliary body, and chorioid in connec- tion. Together these form the middle tunic of the eye, which takes the shape of a sphere, colored dark brown by the pigment which it contains. In front this has a large aperture, the pupil; behind it has a small one, the opening designed for the transmission of the optic nerve. On account of the similarity of the dark sphere, hanging upon the optic nerve as upon a stalk, to a grape {uva), the middle tunic of the eye has received the name of uvea, and also of uveal tract. (a) Iris. The iris * is a disk-shaped membrane, perforated in the center by the pupil.f By its peripheral or ciliary border it springs from the anterior surface of the ciliary body. Prom this point it stretches over the lens, its central or pupillary border lying upon the anterior capsule, and gliding upon it with the movements of the pupil (Pig. 71). By lying in this way upon the lens, the iris obtains a firm support. Hence, when the lens is absent or has lost contact with the iris, the latter is seen to tremble or vibrate with movements of the eyeball (tremulous- ness of the iris, iridodonesis J). Since the umbo of the lens lies farther forward than the spot where the iris originates in the ciliary body, the iris forms a shallow cone, whose apex, directed forward, is cut off short by the presence of the pupil. The shallower the anterior chamber becomes through advancement of the lens, the greater is the altitude of this cone ; if, on the other hand, the lens is absent, the iris extends in a plane. * Iris on account of its rainbow shape, not on account of its color. + Pupilla properly means girl ; perhaps so called because in the pupil one sees a diminutive image of himself reflected from the cornea. So, also, in old German works the pupil is named " Kindlein " (= little child). In Greek, too, the pupil is called K( ,, , i ■ . .1 j. 1 -j j; groove ; re, nasvus ; p, peripheral ( 6 ) ; that lying tO the central Side 01 it is the much narrower pupillary zone (P), which is often distinguished from the ciliary zone by a different coloration. Along the circulus minor may be noticed pitlike depres- sions (crypts, c) in the surface of the iris. Similar but much smaller openings in the anterior surface also exist at the periphery of the iris, close to its root ; but these are not perceived in the living eye, partly because they are too small, partly because they are concealed by the margin of the sclera, which projects in front of them. It is only in blue eyes, especially in children, that this peripheral perforated zone becomes apparent as a dark, almost black, circle {p) close to the root of the iris. The pupillary margin of the iris is seen to be lined by a narrow black fringe (r), which stands out with especial prominence in eyes affected with cataract ; for it contrasts much more forcibly with the white background of the clouded lens than with the black of the pupil of a normal eye. Microscopical Anatomy. — The stroma of the iris consists essentially of numerous vessels running in a radial direction from the ciliary to the pupillary margin. The vessels are inclosed in a thick adventitia, and are surrounded by a loose meshwork of branched and pigmented cells, which fill up the interspaces between them. The vessels, together with the cellular meshwork, form the stroma of the iris, which conse- quently is a very loose, spongy sort of tissue. Close to the pupillary margin of the iris the muscle which closes the pupil — the sphincter iridis — is found imbedded in the stroma (Fig. 71, sp). This is a flat band of smooth muscular fibers, one millimetre broad, lying close to the posterior surface of the iris. On the anterior surface of the iris there is a specially dense layer ANATOMY AND PHYSIOLOGY OF THE UVEA. 253 of cells (anterior limiting layer, Pig. 90, v). Next to this is a layer of endothelium, which is a continuation of the endothelium of Descemet's membrane, and covers the entire anterior surface of the iris as far as the pupillary margin. It is deficient only at those spots which corre- spond to the crypts, including both those at the pupillary (Fig. 71, cr) and those at the ciliary margin (c, c). These crypts, therefore, form apertures which lead into the interior of the tissue of the iris and place its tissue spaces in free communication with the cavity of the anterior chamber. This arrangemen': lavors the rapid change in volume of the iris in the alternating movements of the pupil, since it enables fluid to pass rapidly from the tissue of the iris into the anterior chamber and vice versa. The posterior surface of the stroma of the iris is covered by the posterior limiting membrane and the retinal pigment layer. The for- mer (Fig. 90, h) consists of very even, tense fibers, which extend in a radial direction from the ciliary to the pupillary margin, and hence have been regarded as a dilator pupillae. Physiologically speaking, the function of a dilator does really belong to the posterior limiting membrane, since the pupil is actively dilated by its contraction. Prob- ably, however, this is a case not of muscular but of elastic traction. To the posterior limiting membrane succeeds the retinal pigment layer, which coats the posterior surface of the iris. It extends to the pupillary margin, round which it turns so as to appear a little on the anterior surface of the iris (Fig. 71, at jo), and so forms that black rim which we perceive along the pupillary margin, when looking at the eye from in front. The pigment layer consists of two strata of epi- thelial cells (v and A, Fig. 71, and c and d, Fig. 72), which merge into each other at the pupillary margin. The two together, as embryology teaches us, represent the continuation of the retina to its termination at the pupillary margin (Fig. 89). This layer of the iris is therefore designated as the retinal layer (pars retinalis iridis sive pars iridica retinse), in contradistinction to the anterior layers, which, as they be- long to the uvea, are comprised under the name of pars uvealis iridis (Schwalbe). The color of the iris, which is either light (blue or gray) or dark (brown), is caused by the iridic pigment. There are two kinds of pig- ment in the iris : one lies in the branched cells of the stroma, and is hence called the stroma pigment ; the other fills up the epithelial cells of the retinal pigment layer (retinal pigment). Upon the proportion between the amount of pigment deposited in these two the color of the iris depends. The retinal layer of the iris always abounds in pigment, while the amount of stroma pigment that the iris contains varies greatly. When the stroma contains little pigment, the retinal pigment shows through the thin iris, and appears blue. This is due to the same phe- nomenon that causes a dark background always to appear blue when ANATOMY AND PHYSIOLOGY OP THE UVEA. 255 looked at through a more or less opaque medium. Thus, for instance, through a delicate skin the veins look blue. If the stroma is deficient in pigment, but pretty thick and compact, the iris appears gray. And, finally, the greater the amount of brown stroma pigment that the iris contains, the more this pigment becomes visible and makes the iris ap- pear of its own brown color, while the retinal pigment layer, which lies behind, is more and more concealed by the stroma pigment and with- drawn from view. Not infrequently in an iris, that is but slightly pigmented as a whole, one or two isolated accumulations of pigment are found in the stroma. These then stand out as dark (rust-colored, brown, or black) spots in an otherwise gray or blue iris (nasvi iridis, Pig. 70, n). The presence of a pretty large number of them gives the iris a mottled appearance. Exceptionally, cases occur in which the iris has no pigment either in its stroma or in its retinal layer. Such an iris is found in albinos ; it is translucent, and, on account of its numerous vessels, has a deli- cate, grayish-red color. The examination of the iris in the living eye shows us, besides the details of relief mentioned above, a number of concentric curved lines near the ciliary margin of the iris (/, Fig. 70). They are particularly well seen in a dark iris with a contracted pupil, when by their light color they show ofi well upon the brown background. These are the contraction furrow% of the iris; so called be- cause, as the iris becomes narrower during the dilatation of the pupil, its an- terior surface is disposed in folds, and depressions between the folds (/, /, Fig. 71) form the furrows in question, at the bottom of which the stroma of the iris generally contains less pigment. When the pupil contracts, these folds are smoothed down, and the furrows open out and are then easier to be seen. With the varying dilatation and contraction of the pupil we also notice a change in the rim of pigment upon the pupillary margin : the more contracted the pupil is, the broader this becomes ; on the other liand, when the pupil is strongly dilated, it disappears entirely. When the pupil is very much contracted, we not infrequently observe even Explanation op Fig. 71. — Meridional Sectfon through the Anterior Portion of the Eye. Magnified 16 x 1. — The boundary between cornea, C and sclera, S, is marked at its pos- terior surface by the cross section of Schlemm's canal, s- Anteriorly it is covered by the limbus conjunctivse, Z- ; farther back the cross section of an anterior ciliary vein, cz, is seen in the sclera. The iris is attached by the lig:amentum pectinatura, Z, to the inner posterior wall of Schlemm's canal. On the anterior surface of the iris may be recognized tlie orifices of the crypts both in the circulus minor i.cr) and in the periphery (c), also tlie contraction furrow,/. The posterior surface of the iris is covered with a sheet of retinal pigment which turns forward sharply lilie a spur at the pupillary margin, p. At one spot the posterior layer, ft, of the pig- ment has separated so that the anterior layer, w can be seen isolated. Close to the pupillary margin, the cross section, sp. of the sphincter pupillge is visible. From the posterior wall of Schlemm's canal rises the ciliary muscle, consisting of longitudinal fibers, M, and circular fibers, Mu : the transition from one portion to another is effected by the radial fibers, r. At the anterior margin of the circular portion is seen the cross section of the circulus anteriosus iridis major (a). Upon the ciliary muscle are situated the ciliary processes, P, which are cov- ered by the two layers of the pars ciliaris retinae— namely, by the pigmented cellular layer, pe, which is the continuation of the pigment epithelium, Pe, and by the non-pigmented layer, jyc, the continuation of the retina proper, R. The flat part of the ciliary body, the orbiciilus cili- aris, 0, extends to the ora serrata, o, where the chorioid, Cft, and the retina, P, begin. Upon the orbiculus lie the fibers of the zonule of Zinn, 2, which farther forward pass into the free portion, z,, of the zonula and there inclose the cavity of the canal of Petit, i. The lens, J^, shows at its equator, besides the attachments of the zonular fibers, the cross section, fc, of the ring of nuclei. 256 DISEASES OF THE EYE. Fig. 72. — Posterior Layers of THE Iris of an Albinotic Hu- man Eve. Magnified 350 x 1. a, branched cells of the iris stro- ma; b, posterior limiting mem- brane ; c, anterior, and rf, pos- terior, stratum of the retinal pigment layer. in normal eyes a faint tremulousness of the iris (iridodonesis), which otherwise occurs only in dislocation of the lens. This is due to the fact that with a con- tracted pupil the posterior chamber is deeper and at the same time the greatly dilated iris is considerably thinned — circumstances both of which favor waver- ing of the iris. The retinal pigment layer is composed of two strata of cells, the recognition of which, however, is rendered very difficult by their profuse pigmentation. The two strata can be clearly distinguished from each other only in the albinotic eye (Fig. 73) and in the embryo (and sometimes also in the new- born infant) ; we can then also establish the fact that they are the continuation of the two layers of the retina upon the posterior surface of the iris. The anterior stratum of pigment (c, Fig. 73) arises from the pigment epithelium of the retina; the posterior {d) from the retina proper (Fig. 89). In the adult eye a separation not in- frequently takes place between the two strata, because they are not attached with the same de- gree of firmness to the iris. While the anterior stratum is very intimately adherent to the pos- terior surface of the iris, the posterior stratum readily becomes separated from it (in Fig. 71 the separation has resulted accidentally from the dissection). When adhesions of the posterior surface of the iris to the capsule of the lens (posterior synechias) are torn away the posterior stratum is left as a black coat- ing upon the anterior capsule, while the anterior stratum remains upon the iris. So, too, by penciling the iris we can easily remove the posterior stratum, leaving the anterior stratum behind upon the posterior surface of the iris. Then, when we make a microscopical examination of the iris that we have penciled, we find the anterior stratum intimately connected with the posterior limiting mem- brane. As is universally known, the color of the iris changes in the first years of life. Most children are born with a deep-blue iris. The stroma contains but little pigment and is still very thin, so that the posterior pigment layer is seen through it, having a bluish look. With increasing age the stroma becomes thicker and thicker. If, while this is taking place, the pigmentation does not increase, the iris simply becomes of a light blue or gray; but if, simultaneously, there is an increase of the pigment of the stroma, the iris takes on a brown color. The transformation of a blue iris into a brown one is sometimes confined to a part of the membrane, so that a brown sector is seen in an otherwise light- colored iris. Moreover, the iris of one eye may be blue and that of the other brown. The color of the iris is always proportioned to the pigmentation of the rest of the body. The dark races always have a dark iris. (5) Ciliary Body. 57. The ciliary * body is brought into view when the eyeball is bisected, and the vitreous, the lens, and the retina are removed, so that * From cilia, lashes, because of the fine, radiating folds. The ciliary body is also called cyclon (hence oyolitis), from KixKos, a circle. ANATOMY AND PHYSIOLOGY OP THE UVEA. 257 the uvea is everywhere exposed. The spot where the retina is torn away anteriorly is marked by a jagged line — the ora serrata (u, o, Fig. 73). Corresponding to this there is a change in the coloration of the uvea, which behind this line is brown (chorioid), in front of it black (ciliary body). At the anterior margin of the black zone rise the ciliary processes, about seventy in number. These are conspicuous not only because they jut forward, but also because of their lighter color, their apices being less strongly pigmented than are the depressions between them. The anterior zone of the ciliary body, bearing the ciliary processes, is called the folded part of the ciliary body — corona ciliaris (c^. Fig. 73) ; back of this is the posterior part of the ciliary body — orbiculus ciliaris (or) — which is smooth and of a uniform black color. If we strip off the entire uvea from the cornea and sclera, we get a view of the outer side of the ciliary body. This is covered by a layer of gray tissue — the ciliary muscle. Longitudinal sections (i. e., those carried in a meridional direction, Fig. 71) are the ones best adapted for accurate study of the ciliary body. In such sections the ciliary body appears triangular. Its short- est side looks forward, and at about its center gives origin to the iris. The two long sides of the triangle look inward and outward respec- tively. The inner side bears the ciliary processes {P, Fig. 71), while the outer side is formed by the ciliary muscle (M). Microscopical Anatomy. — If we examine the separate layers of the ciliary body, proceeding from without inward, we first come upon the ciliary muscle. This was discovered by Briicke, and was called by him the tensor chorioideee. It consists of two portions, distinguished by the differing direction of their muscular fibers, (a) The external por- tion contains the longitudinal or meridional fibers — that is, those run- ning from before backward {M, Fig. 71). As these are the ones first discovered by Briicke, they are also called Briicke's portion. The longi- tudinal fibers arise from the external fibrous tunic of the eye, at the boundary between the cornea and sclera (at I), and run straight back- ward to a point at which they gradually are lost in the external layers of the chorioid (Oh), (b) The second portion of the ciliary muscle lies to the inner side of the first, and contains those fibers which have a cir- cular course, and which, hence, in sections made meridionally, are seen in cross section (JJu, Fig. 71). They are designated as Miiller's portion, from their discoverer, Heinrich Miiller. The ciliary processes {P, Fig. 71) are placed upon the ciliary mus- cle. They consist of a connective-tissue stroma, which, along with branched pigment cells, contains an extraordinary number of blood- vessels, so that the ciliary processes must be regarded as the most vascu- lar portion of the entire eyeball. The inner surface of the ciliary body is covered by three layers of tissue. The first of these is a homogeneous 17 naeal a' on 258 ANATOMY AND PHYSIOLOGY OF THE UVEA. 259 membrane, the hyaline lamella of the ciliary body. Succeeding this is a layer of pigmented cells, the pigment epithelium {P, Figs. 74 and 75) ; and, lastly, a single stratum of non-pigmented, cylindrical cells {0} forming the most superficial layer— i. e., the one that adjoins the vitreous humor. The last two layers are the continuation of the retina, which here has ' become reduced to a double row of cells i. e., a pig- mented and .non-pigmented row. They are hence called the pars ciliaris retinm. All three layers pass over upon the posterior surface of the iris, the deepest layer, or hyaline membrane, being continued into the posterior limiting membrane of the iris, while the layers of pig- mented and non-pigmented cells are converted into the two strata of the retinal pigment layer of the iris (pars iridica retinas, c and d, Fig. 73). The place where the iris and the ciliary body are attached to the sclera deserves particular attention. We can readily convince ourselves that the iris does not arise from the sclero-corneal junction, but farther back, so that the most anterior portion of the sclera is still in the con- fines of the anterior chamber. The connection between the sclera and the root of the iris is made by means of loose tissue which arises at the margin of the cornea, and from this point extends backward to the root of the iris (Fig. 71, 1). This tissue, which is called the Ugafnentum pectinatum, fills up the angle between the iris and the corneo-sclera, so that this angle is rounded oif into a sinus — the sinus of the anterior chamber. Histologically, the tissue of the ligamentum pectinatum is composed of superimposed, laminated lamellae, which start from the margin of Descemet's membrane and run backward to a point at which a part of the longitudinal fibers of the ciliary muscle abuts against them. These lamellee consist of trabeculse inclosing rounded alveoli, so as to form, when superimposed, a spongy tissue (Fig. 76). Directly to the outer side of them, just at the boundary between the cornea and sclera, is observed an open space (Fig. 71, s), representing Schlemm's canal (sinus venosus sclerse), the inner wall of which is thus formed by the ligamentum pectinatum. The iris and ciliary body take part in the formation of the two chambers of the eye. The anterior chainler is bounded in front by the Explanation op Fig. 73. — The nasal wall of the orbit is formed by the lamina papyracea (OS planum) of the ethmoid, L, the lachrymal bone, T, and the frontal process, F, of the su- perior maxilla. The last two bones bound the fossa sacci lacrimalis, in which lies the lachry- mal sac, S. The bony walls of the orbit are coated by a periosteum (periorbita), P, from which the palpebral ligaments take their origin. The internal palpebral ligament, I, divides into an anterior limb, v, and a posterior limb, A, which together inclose the lachrymal sac. From the posterior limb arise the fibers of Horner's muscle, H. Ze, external palpebral ligament ; fi and fe, the slips of fascia, likewise passing from tlie periosteum to the internal rectus muscle, J, and the external rectus, B. The skin, N, of the dorsum of the nose passes into the lower lid. at whose free border are seen the cilia and the orifices of the Meibomian glands, m ; between the two extends a gray line, i. At the inner extremity of the lid lies the inferior punotum lacri- male, p, and farther along in the conjunctival sac the caruncle, c, and the plica semilunaris, n. From the eyeball, the lower half of which is exhibited, the lens and along with it the vitreous humor have been taken out, and the pigment epithelium has been removed by penciling. The anterior chamber, fc, the iris, ir, and the ciliary body, consisting of the corona ciliaris, Cj, and the orbiculus ciliaris, or, are visible. Back of the ora serrata, o, is the chorioid with its veins which are aggregated into vortices, v. f, fovea centralis retinae ; c^, central vessels of the optic nerve, O, entering it at e. 260 DISEASES OF THE EYE. cornea, behind by the iris and in the region of the pupil by the an- terior capsule of the lens, and at its margins by the tissue of the liga- mentum pectinatum, beneath which lie Schlemm's canal and the an- terior border of the ciliary body. Even under normal conditions the P c z F c Fig. 74. Fig. 75. Fig. 74. — Portion op a Meridional Section throdgh a Ciliary Process, somewhat behind ITS Apex. Magnified 240 x 1.— The stroma of the ciliary process, S, con.sists of delicate con- nective tissue in which lie the broad and very thin-walled blood-vessels, g. Succeeding these are the two layers of the pars ciliaris retinae. One is the pigment layer, P, representing the continuation of the pigment epithelium ; its cells, on account of their deep pigmentation, dis- close peither their nucleus nor their contour, and they also conceal (as too they do in Fig. 75) the hyaline lamella, which can be rendered visible only by penciling these cells out. The second layer, C, which is uupigmented, consists of a single layer of cubical cells, represent- ing the continuation of the retina proper. Fig. 75. — Superficial Layers op the Flat Portion ^Orbiculus Ciliaris) of the Ciliary Body in Meridional Section. Magnified 270 x 1.— Taken from the same section as Fig. 74. The cells of the pigmented layer, P, of the ciliary body dip into the stroma, 5, of the latter in the form of processes which are club-shaped or gland-shaped (but contain no gland cav- ity). The cells of the superficial non-pigmented layer, C, are here longer than in Fig. 74 and cylindrical. On their tree surface lie the fibers of the zonule of Zinn. depth of the anterior chamber is variable. It is greatest in the eyes of the young, and diminishes with advancing age. Myopic eyes have a deep anterior chamber, hyperopic eyes a shallow one. Even in the same eye the depth of the anterior chamber varies, as it becomes shal- lower during the accommodative act from the protrusion of the anterior surface of the lens. Th& posterior chamber is produced by the iris not being in contact with the capsule of the lens by its whole posterior surface, but only by its pupillary margin. Thus an open space is left between the iris and the lens, which increases in depth from the pupil- lary to the ciliary margin of the iris, and hence in cross-section has a triangular shape. This space, the posterior chamber of the eye, is bounded in front by the iris and \o the outer side by the ciliary body, while its inner and posterior wall is formed by the lens {L, Fig. 71) and the zonule of Zinn (21, Fig. 71), the latter bridging over the inter- space between the lens and the ciliary body. The two chambers com- municate only by means of the pupil. The ciliary muscle is composed of smooth muscular fibers, which do not present a compact mass but are disposed in flat bundles, which are separated by connective tissue, and which interlace repeatedly so as to form a sort of ANATOMY AND PHYSIOLOGY OF THE UVEA. 261 plexus. For this reason there is no well-marked separation between the two portions of the ciliary muscle ; on the contrary, the longitudinal fibers by a very gradual transformation become bent so as to take a circular direction. Those bundles which effect the transition from fibers of one direction to those of another have been denoted by the name of radial bundles (r. Fig. 71). Like the longitudinal fibers they arise fr^m the wall of Schlemm's canal, but, unlike them, they do not extend outward and backward, but directly backward, and pass into the circular fibers. The proportion between longitudinal and circular fibers varies according to the refractive state of the eye. In hypermetropic eyes the circular fibers are strongly developed, while in myopic eyes they are present in much smaller num- bers (see § 144, and Figs. 233, 224, and 225). The region of the angle (or sinus) of the anterior chamber demands particular consideration, both because of its complicated anatomical relations and also because of its importance with regard to the metabolic processes and the dis- eases of the eye. This region was studied in the eyes of animals before it was in human eyes, and hence names were selected at that time which are still in vogue, although they are not appropriate for the human eye. Thus Hueck in- troduced the name ligamentum pectinatum, because he found in the eyes of the Ungulata that, upon stripping the iris from the sclera, the tissue that united these parts projects in a series of ridges resembling the teeth of a comb. The triangular space between the sclera and the root of the iris which is filled by Fig. 76.— Ligamentdm PECTiNATrm (Sorface View). Magnified 700 x 1, TrabeculBB, which show a delicately fibrillar structure, inclose alveoli, the larger of which are eUiptical, and directed so that their long axis lies parallel to the margin of the cornea^ Upon the walls of these alveoli lie cells (endothelial cells) provided with nucleus and large proto- plasmic cell body ; small alveoli are sometimes entirely filled by such cells. the ligamentum pectinatum is also called Fontana's space, because Fontana was the first to describe the rather large cavities which are found in many animals between the lamellae of the ligamentum pectinatum. The ligi/mentmnpectiiiiitum is covered by the endothelial layer which passes over it from the posterior surface of Descemet's membrane to the anterior sur- face of the iris. Through the gaps in the lamellae of the ligamentum pectina- 262 DISEASES OP THE EYE. turn the endothelium passes from the surface of the ligament into the deeper parts of it, and supplies all the lamellse and trabeculse of this spongy tissue with an endothelial lining (Fig. 76). When the iris and the ciliary body are stripped o£E from the corneo-sclera, the ligamentum pectinatum comes away with them. It thus shows the close interrelation between it and the uvea, a relation, moreover, that is also proved by embryology, according to which both the ligamentum pectinatum and its derivative, Descemet's membrane, belong to the uvea. Hence, embryologically speaking, the uvea forms a perfectly closed hollow sphere, consisting of the chorioid, ciliary body, iris, ligamentum pectinatum, and Descemet's membrane. By stripping off the uvea, together with the ligamentum pectinatum, from the corneo-sclera, an opening is made into Sehhmm's canal, the inner wall of which is formed by the ligamentum pectinatum. It is then visible as an open channel running along the boundary between the cornea and sclera — scleral channel. Besides this, the ligamentum pectinatum covers in a part of the an- terior surface of the ciliary body, which therefore, within these limits, likewise belongs to the region of the anterior chamber. Hence inflammatory products, and especially pus, may pass from the ciliary body directly into the anterior chamber, traversing the tissue of the ligamentum pectinatum as they do so. Kew growths also sometimes take this path, starting from the ciliary body and growing forward into the anterior chamber in the region of its sinus (Fig. 105). It was a good while before people got a correct idea of the anatomical rela- tions existing in the region of the anterior and posterior chamber, and even at the present time we very frequently find drawings which represent these rela- tions incorrectly. The existence of the posterior chamber was for a long time contested, it being supposed that the iris came into contact with the lens by its whole posterior surface. If this were the case, the anterior chamber would present quite a different shape, since it would have to be much deeper at its periphery than it is. This state of things is actually observed in those patho- logical cases in which the iris is adherent throughout by means of an exudate to the capsule of the lens. The iris is then found to be retracted at its periph- ery much more than usual (see Fig. 98). The existence of a posterior cham- ber in the normal eye can be demonstrated by freezing a recently extracted eye : upon opening it, we see a ring-shaped piece of ice (the frozen liquid of the pos- terior chamber) lying between iris and lens. (c) Chorioid. 58. The chorioid * is that part of the uvea which lines the posterior section of the eye from the ora serrata to the aperture for the optic nerve. If we observe it in situ, after opening the eyeball and removing the vitreous together with the retina, its inner surface appears smooth and uniformly brown. Then, if we try to strip it ofE from the sclera, we notice that at several spots it is attached more firmly than at others. The most intimate connection is at the margin of the aperture for the * From xopioEiS^j— i. e., like the x^P^o" (= Lat., corium). This latter word sig- nifies " skin," and not merely the epidermis, but also the envelope (chorion) of the embryo in utero ; and, in fact, it is the latter that the chorioid resembles, from its abundant supply of vessels. This word is also erroneously written choroid or choroid. ANATOMY AND PHYSIOLOGY OF THE UVEA, 263 optic nerve ; in addition, loose attachments exist in the places where vessels and nerves enter the chorioid from the sclera, and especially in the region of the posterior pole (region of the posterior ciliary arteries) and of the equator (venae vorticosa). When, after tearing away these connections, we have separated the chorioid from the sclera, we get a view of the outer surface of the chorioid, which has a shaggy appear- ance on account of the shreds of membrane adhering to it. Microscopical Anatomy.— The chorioid consists of five layers, which succeed one another in the following order, proceeding from without inward : 1. The suprachorioid (s. Fig. 77) consists of numerous fine non- vascular but richly pigmented lamella3 lying between the chorioid proper and the sclera {sc). Upon stripping these latter apart these FiQ. 77.— Cross Section through the Chorioid. Magnified 175 x 1. The chorioid consists of the suprachorioid, s, the layer of large vessels, H, the layer of medium- sized vessels, S, the ehorio-capillaris, i?, and the lamina vitrea, G. In the layer of large vessels are recognizable arteries, A. veins, F, and pigment cells, p. The inner surface of the chorioid is covered by the pigment epithelium, P, its outer surface by the sclera, ac. lamellffi are torn in two, and are left hanging partly upon the inner surface of the sclera, partly upon the outer surface of the chorioid, which thus acquires the rough, shaggy aspect above mentioned. 2. The layer of large vessels (Haller) {H, Fig. 77). These are chiefly veins, which are placed very close to each other and anastomose repeatedly. The intervals between the vessels (intervascular spaces) are richly supplied with pigment cells {p), and are hence of a brown color This layer, accordingly, gives the same appearance upon a surface view as if we were looking at a plexus of bright lines (the vessels) upon a dark ground (Fig. 73). This is a picture which we often have the opportunity of seeing with the ophthalmoscope in the living eye (tes- sellated fundus, see Figs. 10 and 143). 264 DISEASES OF THE EYE. Fig. 78. — Pigment Cells of the Stroma of the Chorioid. Magnified 400 x 1. They are branched, anastomosing, connective- tissue cells, with numerous pigment granules and an unpigmented nucleus. 3. The layer of medium-sized vessels (Sattler) (Fig. 77, *S'), which is very thin and but slightly pigmented. 4. The layer of capillaries {chorio- capillar is, or membrana Euyschii —although it was not discovered by Eaysch— .ff, Fig. 77). This con- sists almost exclusively of capil- laries which have a very wide bore, and at the same time are so closely packed together that the interspaces between the capilla- ries are often narrower than the capillaries themselves. This lay- er contains no pigment. 5. The lamina vitrea {or lam- ina iasalis G, Fig. 77), a homo- geneous membrane coating the inner surface of the chorioid. We may briefly summarize the structure of the chorioid in the following way : The chorioid consists mainly of vessels which are arranged according to their caliber in three superimposed layers, in such a way that the largest vessels lie farthest to the outside, the smallest vessels farthest to the inside. The purpose of this arrange- ment is easily comprehended, since the chorioid is in great part de- signed for the nourishment of the tissues lying to the inner side of it (retina and vitreous). Hence the minutest vessels, the capillaries, from which the nutrient plasma of the blood exudes, must lie upon the inner surface of the chorioid. The vascular part of the chorioid is covered on either side by a non-vascular layer — i. e., on the outside by the suprachorioid, on the inside by the lamina vitrea. All the layers of the chorioid, with the exception of the two inneririost ones — the capillary layer and the lamina vitrea — contain pigment inclosed in branched pigment cells (Fig. 78). To its abundant supply of pig- ment the chorioid owes its dark-brown color. The inner surface of the chorioid is covered by the pigment epithelium (P, Fig. 77) which lies upon the lamina vitrea. This, too, was formerly reckoned in with the chorioid, because it remains attached to it after the retina has been stripped off; embryological researches, however, have shown that it really belongs to the retina. It consists of regularly hexagonal cells, each of which, has an unpigmented nucleus, while the protoplasm contains an abundance of pigment granules (Fig. 79). From this the entire layer acquires a dark -brown color. Fig. 79.— Pigmented Epi- thelial Cells of the Retina. Magnified 500 X 1. They are hexagonal epi- thelial cells, with pig- ment granules and an unpigmented nucleus. ANATOMY AND PHYSIOLOGY OF THE UVEA. 265 The uvea in all of its parts is very rich in nerves. The ciliary nerves get to the uvea by piercing the sclera near its posterior pole. They form in the chorioid, and particularly in the ciliary muscle, a dense plexus, in which numerous ganglion cells are intercalated. The iris is also very rich in nerves, but contains no ganglion cells. The ■ iris and the ciliary body contain, in addition to the motor nerves de- signed for the ciliary muscle and the muscular apparatus of the iris, a very great number of sensory nerve fibers which arise from the tri- geminus ; hence, inflammation of these parts is frequently attended with great pain. The chorioid, on the contrary, seems to possess no sensory nerves, since inflammation of this membrane runs its course without producing any sensations of pain. The chorioid is continuous with the flat part of the ciliary body (orbiculus ciliaris), which possesses essentially the same structure as the chorioid, and is distinguished from it only by a somewhat different arrangement of the blood- vessels, and also by the absence of the chorio-capillaris, which ends at the ora serrata. The difference in color between the brown chorioid and the black or- biculus (Pig. 73), so striking to the naked eye, is not referable to a difference in the pigmentation of these parts of the uvea, but to a difference in the pigment epithelium which covers them and which belongs to the retina. All the pigment that is contained in such abundance in the interior of the eye belongs to two categories: 1. In the tissue of the uvea itself there are everywhere found branched cells, of the character of the connective-tissue cells, containing pigment (Fig. 78). These are the pigment cells of the stroma, and the pigment contained in them is called stroma pigment, or, because it lies in the uvea itself, uveal pigment. 2. The inner surface of the uvea is everywhere coated with a layer of pigmented cells, belonging to the retina and having the character of epithelial cells {pigment epithelium, Fig. 79). This pigment, which hence lies not in the uvea but to the inner side of it, is called the retinal pig- ment. These two kinds of pigment are further distinguished by their minute structure. The pigment in the stroma cells of the uvea consists of small amor- phous masses ; but the pigment granules in the cells of the pigment epithelium are short, rod-shaped structures, which should probably be regarded as small crystals, such as occur, very distinctly marked, in some of the lower vertebrates. The pigmentiferous cells, including both those of the stroma and those of the pigment epithelium, are similar in all eyes, but the amount of pigment which they contain varies greatly. To this fact is due the inequality in the pigmentation of eyes; if the cells contain no pigment whatever, the eye is albinotic (Pig. 73). II. Circulation and Metabolism of the Uvea. (a) Blood-vessels. 59. Three systems of blood-vessels exist in the eye— that of the con- junctiva, that of the retina, and that of the uvea (ciliary system of ves- sels). The arteries of the ciliary system are : 1. The posterior ciliary arteries. These arise from the ophthalmic artery, and enter the in- 266 DISEASES OP THE EYE. terior of the eye through the sclera in the region of the posterior pole. The majority of them pass at once into the chorioid (short posterior ciliary arteries, c, c, Pig. 80). Two of them, however (the long pos- terior ciliary arteries, d. Fig. 80), run, one on the outer side, the other on the inner side, between chorioid and sclera as far forward as the ciliary muscle. Here each divides into two branches, which run in a direction concentric with the margin of the cornea, and unite with the branches of the artery of the opposite side to form an arterial circle, the circulus arteriosus iridis major (Fig. 80, h, and Fig. 71, a). This gives off the arteries for the iris, which extend radially from its ciliary to its pupil- lary margin (Fig. 80, i). Shortly before they reach the latter they form by anastomoses a second, smaller vascular circle, the circulus arteriosus iridis minor or the small circle of the iris (Fig. 80, k). 2. The anterior ciliary arteries come from in front, arising from the arteries of the four recti muscles (Fig. 80, e). They perforate the sclera near the margin of the cornea and assist in forming the circulus arteriosus iridis major. The short posterior ciliary arteries are therefore designed mainly for the chorioid, the long posterior ciliary arteries and the anterior ciliary arteries for the ciliary body and the iris. The arrangement of the veins is essentially different from that of the arteries. In the chorioid the capillary network of the chorio-capil- laris (Fig. 80, /) is fed by the arteries. The blood from this flows off through a very great number of veins that keep uniting to form larger and larger trunks. A number of these trunks simultaneously con- verge to a common center, where, consequently, a sort of whorl or vortex is produced by veins coming together from all sides. Fig. 73 shows a surface view of two such vortices, v. These vortices, the number of which amounts to four at least, usually more, lie somewhat behind the equator of the eye ; from them are given off the venae vorticosse, which, perforating the sclera in a very oblique direction, carry off the blood to the outside (Fig. 80, I). In the ciliary processes the arteries break up into a great number of twigs, which pass over into thin- walled veins (g, Fig. 80). These constitute the greater part of the ciliary processes, which, accordingly, consist mainly of vessels. The larger veins which are formed by the union of these vessels, and also most of the veins of the ciliary muscle, pass backward to the vense vorticosse. The veins that come from the iris (it, Fig. 80) likewise pass to the venae vorticosse. Hence almost all the venous blood of the uvea empties into the latter. A portion of the veins coming from the ciliary muscle (m. Fig. 80), however, take an- other course, as they pass out directly through the sclera and thus come into view beneath the conjunctiva, near the margin of the cornea (an- terior ciliary veins. Fig. 80, e^). In their course these correspond to the anterior ciliary arteries ; it is they that principally constitute the violet vessels which we see running backward beneath the conjunctiva ANATOMY AND PHYSIOLOGY OF THE UVEA. 267 in ciliary injection or in stasis within the eyeball (glaucoma). The anterior ciliary veins anastomose with the conjunctival veins, and also Fig. Blood-vessels of the Eye. (Schematic.) (After Leber.) The retinal system of vessels is derived from the central artery, a, and the central vein, a,, ( the optic nerve, which give off the retinal arteries, 6, and the retinal veins, 6,. inese ena i the ora serrata. Or. The system of ciliary vessels is fed by the posterior short ciliary arteries, cc "f^^ POf'^rior long ciliary arteries, I and the anterior ciliary arteries, e. From these ^"f ^J"® ZfJ^^^Jfriosus work of the chorioidal capillaries, /, and of the ciliary body, g, and the «™3„^,,^7?['°™f !^Ai„ „=^„, I, Tiv^Tv, tv,io io=f. onrino- the art.eries of the ins. I. which at the smaller Linnerj circumrerence ot ine laraer lorm tiie unuuiuo ""■"=',', ^V" * .v,„„;n.ii ^nrticnssp I- those iris, .•„ of the ciliary body, and of the chorioid are collected into the venae ™rticosa; i , tnose veiis, however, that come from the ciliary muscle (m) leave the eye as anterior cmd,ry veins, e,. With the latter, Schlemm's canal, n. forms anastomoses. The system 'of conjunctival vessels consists of the posterior coo5"°<=t'^tw!f !,f • "to meet' them- communieate with those branches of the anterior ciliary ™sf>s which ran to meet tne^^^ that is, with the anterior conjunctival vessels, p-and form ^>tb t ?nfrt' nr retSa • i lens • the cornea, o. O, optic nerve ; S, its sheath ; Sc, sclera ; A, chorioid , N, retma , i., lens , H, cornea ; B, internal rectus ; B, conjunctiva. 268 DISEASES OP THE BYE. with Schlemm's canal. The latter is a venous sinus running along the sclero-corneal Junction (Pig. 80, n; Fig. 71, s). The blood-vessels of the eye belong for the most part to the region of the uvea. It is this fact which determines the part played by the latter; for, while the firm corneo-sclera serves for the protection of the eye exteriorly and the retina for the perception of light, to the uvea is allotted the task of providing for the nourishment of the eyeball. Such is the abundance of blood-vessels which it contains that it really consists mainly of them; and by this fact its great tendency to become in- flamed is accounted for. The separate branches of the ciliary system of vessels anastomose repeatedly with each other — a circumstance which favors the compensation of circulatory disturbance. Thus, for instance, in glaucoma, in which the outflow of venous blood through the vense vorticosse is impeded, we see the anterior ciliary veins taking their place and carrying o3 larger quantities of blood than usual. The ciliary vessels likewise supply the sclera with blood, giving oflE a few minute twigs to it as they pass through it. The number of blood- vessels in the sclera, ^however, is very small. Nevertheless, in the immediate neighborhood of the entrance of the optic nerve, from two to four branches of the short posterior ciliary arteries enter the sclera and form in it by anastomoses an arterial ring, Zinii's scleral circle of vessels, surround- ing the foramen for the optic nerve. This is of importance for the nutrition of the optic nerve, because numerous little branches go from it to the optic nerve and its sheaths, and anastomose with the branches of the central artery of the nerve. It is here, then, that the only connection between the ciliary and the retinal system of vessels exists. It not infrequently happens that individual branches arising from the scleral circle of Zinn, instead of remaining in the optic nerve, make a bend and leave the nerve. They then enter the retina and run in it toward the macula lutea. These vessels, which are called cilio-retinal, ordinarily supply with blood a small district of the retina lying between the papilla and macula (Fig. 81). Fig. 81. — Cilio-rbtinal Artery. From the outer and lower mar- gin of the papilla rises a cilio- retinal artery (a), making a hook- like bend. In this case it is larger than usual because it is destined to replace the main infero-external branch (inferior temporal branch) of the central artery, which branch is wanting. {b) Lymph Passages. 60. If we disregard the conjunctiva, thei-e are no lymphatic ves- sels in the eye. They are replaced by lymph channels and lymph spaces. We distinguish the lymph passages into anterior and pos- terior. 1. Anterior Lymph Passages. — The lymph of the anterior section of the eye is collected into two large lymph spaces — namely, the auT terior and the posterior chambers — which communicate by means of the pupil. The outflow of lymph from these spaces takes place by its ANATOMY AND PHYSIOLOGY OF THE UVEA. 269 discharge from the posterior chamber through the pupil into the an- terior chamber ; thence it filters through the mesh work of the liga- mentum pectinatum into the subjacent Schlemm's canal (Fig. 82, S), and from there gets into the anterior ciliary veins (e) with which Schlemm's canal is in direct communication. 3. Posterior Lymph Passages.— These are a,sM\ows: (.J) The hya- loid canal, or central canal of the vitreous (Fig. 82, A), which extends from the point of entrance of the optic nerve forward as far as the posterior pole of the lens. During the development of the eye this —Lymph Passages of the Eye. (Schematic.) S, Sciilemm's canal ; c, anterior ciliary veins ; h, hyaloid canal ; p, perichorioidal space, which communicates by means of the venas vorticosae, v, with Tenon's space, t,t;s, supravaginal space ; ;', intervaginal space ; e ej, continuation of Tenon's capsule upon the tendons of the ocular muscles (lateral invagination). canal lodges the hyaloid artery, which in the fully formed eye disap- pears, while the canal remains. It has its outlet in the lymph spaces of the optic nerve. (B) The perichorioi(3al space (p, Fig. 82) is the space between the chorioid and sclera. It is continued along the ves- sels which pass through the sclera, especially the venae vortieosffi (v), and thus communicates with (C) Tenon's space (Fig. 82, t, t), which lies between the sclera and Tenon's capsule. The outflow of lymph from all these spaces takes place into the lymph passages, which spread 2T0 DISEASES OP THE EYE. out along the optic nerve. These latter are {D) the intervaginal space, which is found between the sheaths of the optic nerve {i. Fig. 82), and {E) the supravaginal space {s, Fig. 82), which surrounds the sheaths of the optic nerve. By far the greatest amount of lymph leaves the eye through the anterior lymph passages. These, therefore, are the more important ; their impermeability leads to serious changes in the eye (glaucoma), while up to the present time nothing certain is known in regard to disturbances of the function of the posterior lymph passages. We owe our knowledge concerning the lymph passages chiefly to Schwalbe. For their study we make use of injections into the tissue of the dead and also of the living eye. Thus we find in what directions fluids penetrate most readily in and between the tissues of the eye. But to justify us in regarding the spaces thus exhibited as lymph passages, proof must also be brought to show that they are coated by a continuous layer of endothelium ; and this, too, Schwalbe has established in the lymph spaces which he discovered. (c) Nutrition of the Eye. 61. The secretion of the fluids of the eye, and also the nourishment of its tissues, take place mainly through the vessels of the uvea. The aqueous humor is a limpid liquid, which in the normal state contains only an excessively small amount of albumin. It is produced by the iris and the ciliary processes, the latter playing the more im- portant part in the process ; for, in cases of congenital or acquired defi- ciency of the iris, the aqueous is still secreted in normal amount. The aqueous secreted by the ciliary processes arrives first into the posterior chamber, from which it passes through the pupil into the anterior chamber. Here it again leaves the eye by way of the ligamentum pec- tinatum and Schlemm's canal. The secretion of aqueous goes on much more rapidly when the latter has been evacuated — e. g., by puncture of the cornea — than it does under physiological conditions. In the for- mer case the anterior chamber is restored as early as a few minutes after it has been evacuated, a thing we have frequent opportunity of observing during operations. The rapid reproduction of aqueous is favored by the fact that after its escape the ocular tension is reduced much below the normal. Hence the blood pours in greater quantity into the vessels of the iris and ciliary body, thus relieved of their ex- ternal pressure, and these expand proportionally and allow fluid to transude from them in greater abundance. This fluid that accumu- lates in the anterior chamber after the evacuation of the aqueous is distinguished from normal aqueous by the considerable amount of al- bumin that it contains. The cornea is nourished mainly by the network of marginal loops of the limbus, and to a small extent also by the aqueous humor which ANATOMY AND PHYSIOLOGY OP THE UVEA. 271 makes its way into it by diffusion. The other two non-vascular tissues of the eye, the lens and the vitreous, are entirely dependent upon the uvea for their nourishment. They obtain nutrient material mainly from the ciliary body, perhaps also from the anterior section of the chorioid. Hence in diseases of these parts we very frequently see cloudiness of the lens and cloudiness and liquefaction of the vitreous, making their appearance as an expression of the disturbance in the nutrition. The process of tissue metamorphosis in the lens appears to be very slow, since pathological changes in it (opacities) often either remain stationary for an exceedingly long time or extend but slowly. The retina has its own vessels, which, however, are situated simply in its inner layers and do not sufiSce for its nourishment. The retina, therefore, especially in its outer layers, is dependent upon the chorioid, whose chorio-capillaris indeed is almost directly adjoining. The chorio- capillaris, furthermore, must be credited with accomplishing the con- tinual regeneration of the used-up visual purple. The aqueous can not be regarded as simply lymph, since it is distinguished from the latter by containing extremely little albumin. It must rather be looked upon as a secretion, in whose formation the two layers of retinal cells (pigmented and non-pigmented) that cover the surface of the ciliary body, play the part of a secreting epithelium. Treacher Collins has called attention to the numerous glandlike processes that the pigment epithelium in the flat portion of the ciliary body gives off (Pig. 75), and ascribes the secretion of the aqueous mainly to them. The liquid that accumulates very rapidly in the anterior chamber after the aqueous has been withdrawn from it, and which is much more albuminous than the normal aqueous, is formed for the most part by direct transudation from the distended vessels of the ciliary processes, which transudation gives rise to numerous blisterlike elevations in the layer of retinal cells lining the ciliary processes (Greeff). With regard to the nourishment of the lens, it is assumed that nutrient material starting from the ciliary body and the anterior part of the chorioid enters it in the region of its equator. Inside of the lens the fluid circulates probably in clefts which lie between the fibers of the lens in the anterior and posterior cortical layers (Schlosser), and which under pathological conditions may become visible as stellate opacities. The lymph leaves the lens probably through the anterior capsule and empties into the anterior chamber (Samel- sohn). As regards the retina, various facts indicate that it is likewise dependent in part for its nourishment upon the chorioid, and particularly upon the most an- terior layer of the latter — i. e., the chorio-capillaris. This layer extends for- ward only as far as the retina itself, or at least the complicated structure of it, does— that is, as far as the ora serrata. Again, at that spot where the retina displays its functions most actively — i. e., in the region of the macula lutea — the capillary loops of the chorioid are most densely disposed ; and, lastly, there are many animals in which the retina has no vessels whatever, and hence evidently can be nourished only by the chorioid. The outflow of lymph from the retina takes place through the lymph sheaths surrounding the retinal vessels. 272 - DISEASES OP THE EYE. (d) Intra-ocular Pressure. 62. For the purpose of simplifying the study of the conditions of pressure, we may leave the lens out of consideration, and think of the eyeball as a capsule filled with fluid. The capsule is the fibrous cor- neo-sclera, which has only a very small degree of elasticity. The fluid contained in the capsule exerts upon the inner surface of the latter a pressure which, in accordance with the laws of hydrostatics, is trans- mitted with the same intensity in every direction, and hence presses with the same weight upon every unit of surface of the wall. A square millimetre of the posterior surface of the cornea has therefore the same pressure to bear as a square millimetre of any portion of the sclera. The intensity of intra-ocular pressure depends upon the relation between the capacity of the capsule and the amount of its contents. If the former becomes smaller or the latter greater, the pressure rises, and vice versa. Under physiological conditions, the capacity of the capsule — i. e., the volume comprised by the cornea and sclera — under- goes such inconsiderable variation that it may be neglected, and the capacity regarded as constant. The variations in intra-ocular pressure are hence referable to changes in the amount of matter contained in the eyeball, which may be increased or diminished. For example, the pressure at once sinks considerably when the aqueous has been evacu- ated by puncture of the cornea. Those portions of the contents of the eyeball whose amount is vari- able are the aqueous, the vitreous, and most of all the blood that circu- lates in the vessels of the inner tunics of the eye. Every increase or decrease of blood pressure in these vessels must result in a correspond- ing change in the ocular tension. Other causes, too, such as changes in the form and volume of the iris and ciliary muscle, the pressure of the lids and of the exterior muscles of the eye upon the ball, etc., can alter it. One might therefore be inclined to believe that it was subject to considerable variations. But, on the contrary, observation teaches us that the intra-ocular pressure under normal conditions is pretty co7i- stant. In fact, a regulation of the tension is effected by the circum- stance that the outflow of the fluid of the eye through the lymph channels (excretion) changes in such a way that variations of pressure are at once compensated for. For example, the pressure in the whole vascular system, and consequently in the eye as well, may be elevated as the result of great muscular effort. The intra-ocular pressure is thus heightened ; but proportionately more of the intra-ocular fluids which are subjected to this increased pressure are forced out of the eye through the excretory channels, so that the pressure very soon sinks again to its normal level. The converse would occur in a case in which the pressure has been diminished (e. g., in consequence of an escape of ANATOMY AND PHYSIOLOGY OF THE UVEA. 273 the aqueous humor) ; theu more blood flows into the vessels of the uvea, now subjected to less pressi;ire, and a more copious outflow of fluids into the interior of the eye (secretion) is the result. But at the same time the outflow of ocular fluids through the lymph channels (excretion) is diminished, because the pressure to which the ocular fluids are sub- jected is less. In this way the normal pressure is very soon restored. The practical estimation of the intra-ocular pressure is performed by palpating the eyeball through the closed lids, just as if we were in- tending to test for fluctuation. We determine in this way the degree of tension of the eye. This, to be sure, is not identical with the intra- ocular pressure, since the latter depends upon other factors as well, and particularly upon the degree of hardness and elasticity of the ocular tunics. But in any case it is proportional to the intra-ocular pressure, and may therefore be employed in practice as expressive of it. Even under normal conditions the ocular tension varies within cer- tain limits in different individuals; in general, the eyes of elderly per- sons feel harder than those of the young. Hence very slight patho- logical changes of tension can only be recognized with certainty as morbid, when we can make use of the second, normal eye of the same man for purposes of comparison ; greater alterations of pressure, how- ever, make themselves evident at once. It has been agreed to denote the normal tension by the expression Tn ( I' = tension or tone). Of increased tension (hypertony) we distinguish three degrees: T+1, T-\- 2, and T-\- 3, which are arbitrarily selected, and indicate approxi- mately : tension noticeably increased — greatly increased — hard as stone. Similarly, we employ for diminished tension (hypotony) the designa- tions T- 1, T-2, and T- 3. The intra-ocular pressure plays an important part both under physiological conditions and also in diseases of the eye, and has hence been the subject of numerous investigations, chiefly experimental. For its exact measurement a manometer has been employed, one arm of which is connected with a cannula, the other being introduced into the eye. In this way it has been found that in the healthy human eye the average pressure equals that of a column of mercury twenty-six millimetres high; under pathological conditions (glaucoma) the pressure may exceed seventy millimetres (Wahlfors). This method of meas- urement, however, is practically inapplicable on account of its being dangerous for the eye. Tonometers of various construction have therefore been devised, which measure the intra-ocular pressure by being simply placed upon the eye and impinging against it ; but none of these instruments have so f&r found their way into practice. In the assumption above made, that the eyeball is represented by a capsule filled with liquid, the lens and its retaining ligament, the zonula of Zinn, are left out of consideration. These two together form a diaphragm dividing the interior of the eyeball into a smaller anterior and a larger posterior section. It is hence possible that the pressure is not the same throughout the whole in- terior of the eye, as is assumed above, but that its action is different in the anterior chamber from what it is in the cavity of the vitreous, since the dia- 18 2Y4 DISEASES OF THE EYE. phragm bears a part of the pressure. Under ordinary circumstances, to be sure, this is not the case, since the zonula, owing to its elasticity, gives way toward the side of less pressure, and hence, in general, the pressure in all parts of the eye may be regarded as equally great. Nevertheless, a difference in pressure may be developed when the zonula is tightly stretched, as is the case, for ex- ample, immediately after the evacuation of the aqueous, when the lens pushes forward against the cornea and so tightens the zonula. Then the pressure in the anterior chamber is practically nothing, while the pressure in the vitreous main- tains a certain height. In this case the difference in pressure induces increased filtration of fluid from the vitreous in the anterior chamber — a circumstance that contributes to the more speedy replenishment of the chamber. That the reaccumulated aqueous really does arise in part from the vitreous, and is not simply secreted by the ciliary processes, is proved by the fact that even in the dead eye the anterior chamber fills up again within a short time after the aque- ous has been evacuated (Deutschmann). And it is on this account that in the living eye also repeated punctures of the anterior chamber cause more rapid tissue metamorphosis in the vitreous, and hence prove useful in many cases of disease of the latter. III. Paeticipatiok of the ITtea in the Visual Act. 63. The iris forms a diaphragm which, as in the case of many optical instruments, is interposed between the refracting portions of the eye. It has a double task to perform : it prevents an excessive amount of light from entering the eye and so dazzling it and injuring the retina, and it cuts off the marginal rays. These are the rays that pass through the peripl:iery of the cornea and of the lens, and which, being less regu- larly refracted, would, unless arrested, impair the sharpness of the reti- nal image. In order to be perfectly impermeable to light, the iris has a pigment layer on its posterior surface. The iris has the advantage over the artificial diaphragms of optical instruments that its size changes spontaneously to suit the circumstances of the case. For this purpose there exist contracting fibers (sphincter pupillae) and dilating fibers (posterior limiting membrane). Moreover, the vessels of the iris must be considered as also taking part in this process, since by their disten- tion the iris becomes broadened and the pupil consequently contracted, and vice versa. The contraction of the pupil is governed by the oculo-motor nerve, which supplies the sphincter pupillae (and also the ciliary muscle) through the ciliary ganglion and the ciliary nerves. By stimulation of the oculo-motor nerve, contraction of the pupil is produced; by its section or paralysis, dilatation of the pupil. Dilatation of the pupil is dependent upon the sympathetic, which derives the fibers destined for the pupil from the cilio-spinal center of the cervical spinal cord. Irritation of this center or of the cervical sympathetic produces dilatation, and paralysis of it contraction of the pupil. ANATOMY AND PHYSIOLOGY OP THE UVEA. 275 The reaction of the pupil takes place, involuntarily and uncon- sciously. It is either reflex, in which case the stimulus is transmitted from centripetal nerve channels to the nerves of the iris, or it is asso- ciated, in which case the pupillary fibers of the oculo-motor nerve are set into action simultaneously with other fibers of the same nerve. The stimulus to reflex reaction of the pupil is set in action — 1. By light. This produces contraction of the pupil, while con- versely as the illumination diminishes the pupil dilates. The reflex arc in this case passes through the optic nerve to the nucleus of the oculo- motor nerve and along the latter to the eye. The reaction for light always affects both eyes — i. e., if the light falls into one eye alone, the pupil of the other eye also always contracts (consensual reaction). The reaction takes place in both eyes in exactly the same way — that is, ap- pears at the same time and reaches the same pitch. The reaction of the pupil to light is exceedingly sensitive, and is employed with great advantage to determine objectively whether an eye has any sensation of light or not (particularly in children, malingerers, etc.). 2. Toward sensory stimuli, no matter what part of the body they affect, the pupil reacts by dilating. Hence, in deep sleep, and also in profound narcosis, in which sensory stimuli no longer produce reflexes, the pupil is very much contracted, dilating, however, the moment that waking from the sleep or from the narcosis occurs. Strong psychic stimuli — e. g., fright — in like fashion produce dilatation of the pupil. The associated reaction of the pupil always consists of a contrac- tion. It occurs — 1. In convergence (synergy with the internal recti). 2. In accommodation (synergy with the ciliary muscle). Since under physiological conditions every act of accommodation is accom- panied by a corresponding convergence, and the contraction of the pupil keeps pace with both, we have here as a regular thing a uniform consentaneous action of the sphincter pupillse, the ciliary muscle, and the internal rectus. These muscles are all supplied by the oculo- motor nerve, so that their associated action depends upon a simul- taneous excitation of the several bundles of fibers in this nerve sup- plying them. Since the pupil reacts to stimuli of so many kinds and varying so greatly in degree, it is in a state of constant motion. But in every case the pupils of the two eyes are equally large. " Inequality of the pupils is always a pathological phenomenon. The mean width of the pupil differs with the individual and also alters with the age. Very greatly contracted in newborn infants, the pupil soon becomes more dilated, and then becomes smaller again in manhood, and still more in old age. In old people also the reaction of the pupil becomes slug- gish, in consequence of the unyielding character of the tissue of the iris, and especially of the sphincter (rigidity of the sphincter). 276 DISEASES OP THE BYE. 64. Reaction of the Pupil to Poisons. — There is a series of alka- loids which produce either dilatation of the pupil (mydriasis) or its contraction (miosis).* These substances are accordingly distinguished into mydriatics and miotics. They always act upon the ciliary muscle in the same manner as upon the sphincter iridis. The most important of the mydriatics is atropine, the most important of the miotics are eserine and pilocarpine. 1. Atropine paralyzes the sphincter and the ciliary muscle, and hence results in dilatation of the pupil and also in inability to see clearly near by. The dilatation of the pupil is a very considerable one. If, in the case of a dilatation of the pupil caused by oculo-motor paralysis, atropine is instilled, the pupil becomes still more dilated. This proves that atropine, besides producing paralysis of the contract- ing fibers, causes also stimulation of the dilating fibers. The effect of the atropine makes its appearance in from ten to fifteen minutes after the instillation, and soon reaches its maximum. Commencing with the third day it begins to decrease again, but does not disappear completely until after the lapse of a week. The instillation of atro- pine, therefore, causes the patient a disturbance of pretty long dura- tion, and hence should be employed only when there is good reason for it. In practice, a one-per-cent solution of sulphate of atropine is most frequently employed. If it is desired to obtain a particularly intense effect, a granule of the atropine salt in substance is placed in the con- junctival sac, where it is dissolved by the tears, and affords a concen- trated solution. In this case we must be on the lookout for symptoms of general poisoning, which do not ordinarily develop with the instilla- tion of the one-per-cent solution. These symptoms consist in a trouble- some sense of dryness in the throat, nausea, reddening of the face, and subsequently faintness, or even loss of consciousness, and acceleration of the pulse. In case of marked poisoning the pupil of the other eye also, which has not been treated with atropine, is always dilated. The poisoning is effected by the entrance of the atropine into the nose along ■with the tears and its absorption in excessive quantity by the nasal mucous membrane. Hence we may preclude the development of poi- sonous symptoms, especially in applying atropine in substance, by pre- venting the tears from running down into the nose. For this purpose •we draw the lower lid for a short time away from the eyeball, so that the tears are poured out upon the cheek, or we compress the lachrymal sac with the finger. In serious cases of poisoning, the subcutaneous injection of morphine is indicated as the antidote. * From /ifiaitns, contraction ; hence miosis, and not myosis, as it is generally written (Hirschberg). The derivation of fivSplaa-is is uncertain. This word was already used by the ancients to signify dilatation of the pupil, and also the blind- ness that is so frequently associated with it. ANATOMY AND PHTSIOLOaY OF THE UVEA. 271 We are not to conceive of the action of atropine upon the pupil in the same light as if it had got by absorption into the circulation, as is the case when it is administered internally. For in this case the pupils of both eyes would necessarily be dilated, while, as a matter of fact, the dilatation of the pupil occurs only on the side in which the instillation has been made. The action, accordingly, is a local one, and takes place from the atropine passing through the cornea by diSusion and getting into the aqueous humor so as to act directly upon the iris. We can prove this by a simple experiment, by dropping atropine into one eye, and, as soon as the pupil has dilated, evacuating the aqueous by paracentesis. If, then, this aqueous is introduced into the other eye, it excites a dilatation of the pupil in the latter — a proof that it con- tains atropine. In a similar way is the action of the other mydriatics and miotics upon the iris to be explained. 2. Eserine (also called physostigmine) has an action exactly the opposite of that of atropine, since it places the sphincter iridis and the ciliary muscle in a state of tonic contraction. Consequently, miosis develops so that the pupil is about the size of a pin's head, with adjust- ment of the eye for the near point, as if marked myopia were present. We generally apply sulphate of eserine in one-per-cent solution. This solution, when freshly prepared, is colorless, but after some days be- comes red, although without losing its activity. The instillation of eserine produces, simultaneously with the changes in the iris, a feeling of great tension in the eye, and often also headache and even nausea, so that with many persons it can not be employed. For tliis reason hydrochloride of pilocarpine, prescribed in a one- to two-per-cent solu- tion, is recommended as a miotic for ordinary use. Its solution keeps better than that of eserine, and does not act as powerfully as the latter, but is not accompanied by any unpleasant complications. Eserine is best reserved for those cases in which pilocarpine is ineffectual. The action of miotics is of shorter duration than that of the mydri- atics, and is also less powerful. Hence a pupil contracted by eserine or pilocarpine can be dilated by atropine, but a pupil dilated by atropine can not be contracted by a miotic. 3. Cocaine dilates the pupil, and hence would seem to call for men- tion in this place, although, strictly speaking, it does not belong to the mydriatics proper— that is, the dilatation of the pupil by cocaine is not produced, as in their case, by a paralysis of the sphincter pupilla, but simply by contraction of the dilator fibers and also by constriction of the blood-vessels of the iris. The dilatation of the pupil is therefore only a moderate one, and the reaction of the pupil to light persists ; moreover, mydriatics and miotics still produce an effect. If cocaine is instilled into an eye the pupil of which has been dilated by atropine, the dilatation increases somewhat ; hence the mydriasis produced by the simultaneous action of atropine and cocaine is the most consider- 278 DISEASES OP THE EYE. able that can possibly be attained. The accommodation is not par- alyzed by cocaine, but only somewhat weakened. Besides acting upon the iris, cocaine produces also the following effects: The conjunctiva becomes very pale, and at the same time the patient has a feeling of cold in the eye. The palpebral fissure is more widely open and the act of winking is less frequent, so that the cornea may readily become dry upon its surface. Sometimes the eye is pro- truded somewhat forward, and the intra-ocular tension slightly dimin- ished. The practically important phenomenon, however, is the antes- thesia shown by the superficial tissues of the eye (cornea and con- junctiva). The effects of cocaine are best explained upon the assumption that it acts as a stimulant to the fibers of the sympathetic. The contrac- tion of the vessels thus produced causes the pallor of the conjunctiva; the contraction of the superior and inferior palpebral muscles (see § 105), which are also supplied by the sympathetic, is the cause of the dilatation of the palpebral fissure ; and the contraction of the iridic ves- sels combines with the contraction of the dilator fibers of the iris in producing the mydriasis. Whether the anaesthesia of the surface of the eyeball is to be referred to its bloodless state or not, has not yet been determined with certainty. Owing to this ansesthesia the reflex move- ments of the lids are abrogated. Cocaine was introduced into ophthalmology by Koller, and is em- ployed under the form of the hydrochloride in a two- to five-per-cent solution. Its most frequent use is to produce anajsthesia for the per- formance of operations (see § 151) ; in addition, it is instilled to ame- liorate the pain in superficial inflammations, especially of the cornea, and also to diminish photophobia and blepharospasm. It may also be employed to dilate the pupil for examination with the ophthalmoscope. The ciliary body takes part in the visual act, since it contains the ciliary muscle, which provides for accommodation (see § 139). The ciliary muscle acts synergetically with the sphincter pupillae, and, like it, is paralyzed by mydriatics and thrown into spasms by miotics. The cliorioid takes part in the visual act inasmuch as it supplies the visual purple, and also because its pigment, together with the pig- ment epithelium of the retina, forms the dark coating of the interior of the eye, which is essential for the distinctness of the retinal images. Besides the physiological forces (muscular and elastic fibers), which alter the width of the pupil, there are purely mechanical factors which require consid- eration in this connection. This is the case, for instance, with the contraction of the pupil that regularly occurs when the aqueous escapes. This contraction is of practical importance in the performance of many operations. When, for instance, we perform discission of cataract through the cornea, we take care not to let the aqueous escape, since the consequent contraction of the pupil would expose the iris to greater pressure from the swelling lens. That this con- ANATOMY AND PHYSIOLOGY OF THE UVEA. ^79 traction owes its origin to purely mechanical causes, is deduced from the fact that it occurs even in the eye of a dead man when the aqueous is evacuated. Dilatation of the pupil manifests itself by a sense of dazzling. Sometimes the patients also allege that objects appear smaller (micropsia). This phenome- non, however, does not depend upon the dilatation of the pupil, but upon the paralysis of accommodation, which is generally present at the same time, and is therefore also observed when the latter alone is present. (For its explanation see under paralysis of accommodation, § 150.) Conversely, in contraction of the pupil, sometimes-i. e., if spasm of accommodation is at the same time present— objects appear larger (macropsia). Moreover, obscuration of vision is often complained of, because less light enters the eye through the contracted pupil. In very marked miosis, whether occurring after the employment of miotics or appearing spontaneously (e. g., as the result of tabes), the pupil is frequently found to be irregular and slightly angular, although no synechi* exist. The reaction of the pupil to light is a very valuable sign of the presence of perception of light : in the first place, because it is exceedingly sensitive ; and, secondly, because it demonstrates the existence of perception of light independ- ently of the statements of the patient. Its usefulness is still further enhanced by its disclosing in the pupils of both eyes (through the consensual reaction) the perception of light by one eye. How is this consensual reaction efiEected ? From the retina of each eye (e. g., the right eye, M, Fig. 83) fibers pass through the chiasm partly into the right, partly into the left optic tract (Fig. 83, T and Ti). From these the stimulus is transmitted directly to both right and left oculo-motor nuclei {Kand A'l) ; then each nucleus sets up a contraction of the pupil on its own side. The consensual reaction, therefore, is really as direct as is the pupillary reaction of the illuminated eye itself. The result of the consensual reaction is that under normal conditions both pupils must be of equal diameter, even if only one of the eyes is exposed to the impact of light, or if the sensitiveness of the two eyes to light is difierent. Inequality of the pupOs (anisocoria) is always pathological. For the reasons given it can never take its origin from the centripetal fibers (optic-nerve fibers), but is always caused by a disturbance in the centrifugal channels (oculo-motor nerve and its center). In testing the perception of light by the reaction of the pupils, we must not lose sight of the fact that there are cases in which, although the perception of light is present, the reaction is absent ; and, conversely, cases in which, with good reaction, there is yet no perception of light. (o) The cases in which the pupil does not react to light, although the percep- tion of light is present, are frequent. The iris may be paralyzed either artificially by mydriatics, or by disease, such as oculo-motor paralysis or paralysis of the nerves of the iris due to increase of tension or to inflammation. In the same category belong those cases in which the iris is mechanically prevented from moving by adhesions to the posterior capsule of the lens or to the cornea. In all these cases, however, consensual reaction of the pupil takes place in the other eye, provided that that is healthy. The test for the perception of light in such a case, then, would be performed by alternately exposing to light and •screening the eye to be tested, and meanwhile watching the pupil of the other eye for any movements that it might make. The absence of the reaction to light can also be caused by an interruption in 280 DISEASES OF THE EYE. the course of the reflex arc. This occurs in spinal diseases, particularly in tabes dorsalis; also in progressive paralysis. In these cases the pupil is either found ,— ' Accommodation Convergence Fig. 83.— Schematic Representation of the Optic Tracts. The field of vision common to the two eyes is composed of a right half, (?, and a left half, Gi. The former corresponds to the left halves, I and Zj, of the two retinae, the latter to the right halves, r and r^ . The boundary between the two halves of the retina is formed by the vertical meridian. This passes through the fovea centrahs, /, in which the visual line ( V) drawn from the point of fixation, i^, impinges upon the retina. The optic nerve fibers arising from the right halves, r and r,, of the two retinae (indicated by the dotted line") all pass into the right optic tract, T, while the fibers belonfjing to the left halves, I and l^ , of the two retinae pass into the left optic tract, Tj. The fibers of each optic tract for the most part pass to the cortex of the occipital lobe, S, forming Gratiolefs optic radiation, S ; the smaller portion of them, m, goes to the oculo-motor nucleus, K. This consists of a series of partial nuclei, the most anterior of which sends fibers, P, to the pupil (sphincter iridis) ; the next one sends fibers, A^ to the muscle of accommodation ; and the third sends fibers, C, to the converginc: muscle (internal rectus, i). All three bundles of fibers run to the eye in the trunk of the oculo- motor nerve, Oc. Division of the optic tract at o g or at e e produces right hemiopia ; and in the former case there would be no reaction to light on illuminating the left half of either retina. Division of the chiasm at s s produces temporal hemiopia. Division of the fibers, th, abolishes the reaction of the pupil to light, but leaves the sight and also the associated con- traction of the pupil in accommodation and convergence unaffected. ANATOMY AND PHYSIOLOGY OF THE UVEA. 281 to be perfectly immobile, or its reaction for accommodation and convergence is retained, while the reaction for light has disappeared {Argyll- Robertson pupil). In the latter case the reflex arc running from the optic nerve to the oculo-motor nucleus is interrupted (Fig. 83, m), while the connections of the centers for the pupil, for accommodation, and for convergence, which adjoin each other in the oculo-motor nucleus, are undisturbed. The reflex immobility of the pupil in tabes dorsalis and in progressive paral- ysis is generally combined with a marked contraction of the pupil (so-called spinal miosis), but it also is found at times with a normally wide or even with a dilated pupil. (J) It also happens that the reaction of the pupil to light is present, mthout there being any perception of light. This occurs when the lesion is situated high up in the optic tract. The fibers of the optic nerve ascend to the cerebral hemispheres and terminate in the cortex of the occipital lobe {B, Fig. 83). But, some time before this takes place, those fibers (ot) of the reflex arc, which pass to the center of the pupillary movements, branch off from the optic tract. If, then, the optic tract is interrupted above the place where they are given oS (e. g., at ee), stimulation of the optic nerve fibers no longer reaches the cere- bral cortex and hence excites no perception, and yet the pupillary reflex is still regularly produced. The same thing would happen if the cerebral cortex itself were through some lesion incapacitated for performing its functions. In these cases, however, the lesion of the optic tracts [or of the cortex] would have to be bilateral, as otherwise hemiopia and not blindness would be present (see § 100). For this reason it is clear why such cases, in which blindness exists, even though the examination of the eye gives negative results and the reaction of ,the pupil to light is preserved, are very rare (occurring, for example, in ursemic amaurosis, see § 96), so that under these circumstances our first thouglit would be of simulation or of hysteria, and we would examine for these conditions first. In general, the pupil dilates upon the application of sensory stimuli. An exception to this rule is when the stimuli act intensely upon the eye itself. In this case the pupil contracts, and does so in consequence of the hypersemia of the iris produced by the stimulus (see § 66). Atropine is such an efficient mydriatic that exceedingly small quantities— the millionth part of a gramme— suffice to dilate the pupil. Sometimes all that we have to do in order to get a dilatation of our own pupils is to instill atropine into another person's eye, and in so doing moisten our fingers and then through carelessness touch our own eyes with them. Dilatation of the pupil may also be produced by the internal use of atropine or of drugs which contain it. The most frequent occurrence of this sort is when patients who take bella- donna internally complain of being dazzled, and of not seeing well near by in their work. We find in such cases moderate dilatation of the pupil and dimi- nution in the power of accommodation. With many people there exists an intolerance of atropine. This manifests itself in various ways : (a) By the development of toxic symptoms, such as dry- ness in the throat or nausea, with even small doses. This is especially apt to occur after the long-continued use of atropine. (J) By the production of a catarrh (atropine catarrh), which is usually characterized by the formation of numerous follicles. Here, again, a pretty long-continued use of atropine is re- 282 DISEASES OF THE BYE. quired to produce the effect, (c) In many persons a single drop of atropine is enough to bring on marked redness and swelling of the lids, looking like an attack of erysipelas. In these and similar cases the atropine must either be simply abandoned, or be replaced by another mydriatic, according to circum- stances. Among the other mydriatics that we are acquainted with are hyoscy- amine (isomeric with atropine), scopolamine (formerly known as hyoscine), du- boisine (a mixture of hyoscyamine, hyoscine, and of other alkaloids, whose nature is not very precisely known), homatropine (prepared synthetically by Ladenburg from tropine and mandelic acid), ephedrine, pseudo-ephedrine, and gelsemine. Of the alkaloids mentioned, only three are at all in frequent use — namely, duboisine and scopolamine on the one hand, and homatropine on the other. Sulphate of duboisine acts like atropine, scopolamine hydrobromide more intensely, and both are employed instead of it in those cases in which it is not tolerated. Homatropine hydrobromide has a feebler and, what is most im- portant, a less enduring action than atropine, its effects lasting for scarcely more than about five hours.* It is hence a valuable agent when a transient dilatation of the pupil for purposes of examination of the eye is all that is required. Eserine is the most efficient of the miotics, but is frequently not well borne, because in many cases it excites violent headache, which may lead to vomiting. These symptoms are not to be regarded as due to a general poisoning, but are caused by the marked contraction of the pupil, by which the nerves of the iris are strongly pulled upon. Hence, the symptoms are absent when marked con- traction of the pupil fails to take place — e. g., in atrophy of the iris or in solu- tions of continuity of the sphincter (colobomata, fissures, etc.). In such cases eserine should be preferred to pilocarpine. Pilocarpine is employed in ophthalmology by two entirely different methods — locally by instillation into the eye, and internally in the shape of a hypodermic injection. In the first way it is much employed for contracting the pupil, and especially for diminishing the intra-ocular pressure in glaucoma. In subcutaneous injection (of 0.01 to 0.03 gm. per dose) pilocarpine is used to produce diaphoresis. If, as happens with many patients, it produces great nausea, diaphoresis may be effected by means of sodium salicylate. Of the latter salt the patient takes 1 to 3 gm. in a cup of hot tea (linden flower or elder tea) or of hot lemonade, and stays, covered up warm, in bed. In this case the specific action of the salicyl is combined with the diaphoresis. All patients, however, do not sweat sufficiently under the administration of sodium salicylate, and in others the latter excites digestive disturbance. In such cases diaphoresis may be pro- duced by a hot bath, upon leaving which the patient is wrapped in a dry woolen blanket and put to bed, for some hours. This method produces abundant trans- piration with a fair degree of certainty and without special bad consequences, but owing to the circumstances of the case is not always applicable. Diapho- resis may be induced every day, or every other day, according to the patient's strength. During the treatment the patient should take altogether as little liquid as possible, since what we are trying to effect is the absorption of patho- logical effusions by the removal of a quantity of water from the tissues. [* With solutions of homatropine of the strength usually employed for testing the refraction (two to three per cent), the effect on the pupil and the accommoda- tion lasts from twenty-four to thirty-six hours. — D.] ANATOMY AND PHYSIOLOGY OF THE UVEA. 283 Diaphoretic treatment is contra-indicated in heart disease and marked atheroma of the arteries; and pilocarpine in particular is contra-indicated in pregnancy. Diaphoresis is much employed in ophthalmology, and mainly (1) in violent acute inflammations, especially scleritis, irido-cyclitis, chorioiditis, retinitis, and retrobulbar neuritis ; (3) for clearing up opacities of the vitreous ; (3) for pro- ducing absorption of cfiused blood; (4) in detachment of the retina; (5) in rheumatic paralyses. Both the mydriatics and the miotics may be introduced into the eye in the form of an ointment, instead of in solution. Small gelatin disks containing a certain quantity of the alkaloid are also made, which, when introduced into the conjunctival sac, become dissolved and so develop their activity. What eftect do mydriatics and miotics exert upon the intra-ocular pressure ? So far, observers have not arrived at concordant results in regard to this matter, but at least this much has been proved by experiments, that in the healthy eye the alkaloids cause only very insignificant variations of tension. The case is altogether different when elevation of tension exists, or there is a tendency to it; then atropine may raise the tension very considerably, while eserine and pilocarpine noticeably diminish it. Besides cocaine, holocaine and eueaine have recently been employed as anaes- thetics. IV. Development of the Eye. 65. The eye develops from a protrusion which forms on both sides of the first cerebral vesicle. This invagination, which is called the primitive ocular vesicle (Fig. 84, a), remains in connection with the cerebral vesicle by means of a pedicle, which, at first broad, afterward more narrow, be- comes subsequently the optic nerve {b). Its surface is covered by the ectoderm {E E). Upon this ectoderm, at a point correspond- ing to the apex of the ocular vesicle, there soon forms a thickening. This is the first rudiment of the lens, and the way in which it is formed is that the ectoderm here grows thicker, becomes folded upon itself, and forms an everted pouch directed toward the ocular vesicle {L, Fig. 85). This pouch deepens, and finally becomes shut in in front so as to form a closed sac, the lens vesicle (A Fig. 87 B). The lens is accordingly an epithelial structure,' being a derivative of the external germinal layer, and in the beginning consists of a hollow vesicle, which afterward becomes filled up by the growth of its cells and is con- verted into a solid sphere. In proportion as the ectoderm at the site Fig. 84.— Section through the Embryonic Eye at a Period of i)£velopment correspond- ing to that of a human em- BRYO OP Twenty-one Days. Magnified 100 x 1. The primitive ocular vesicle, a, is a protrusion from the first cerebral vesicle, 6, from which it is separated by a shallow constriction. It is surrounded by the cells of the mesoderm, Jlf, over which passes the ec- toderm, E, consisting for the most part of a single layer of cells. 284 DISEASES OP THE EYE. of the primitive lens pushes against the ocular vesicle, the surface of the latter is indented. Thus a flask-shaped structure with double walls is formed out of what was once a round sac (Pig. 86). This is called the secondary ocular vesicle, which is hence the primitive ocular vesicle Fig. 85. FiQ. 86. Fig. 85.— -Section through the Embryonic Eye at a Period of Development correspond- ing TO that of a Human Embryo of Twenty-two to Twenty-five Days. Magnified 100 X 1. The vertically made section passes through the fcetal ocular fissure. The ectoderm, E, dips in somewhat at the site o£ the lens-proton, i, and besides is thickened, being made up here o£ several layers of cells. Corresponding to this in-dipping, the ocular vesicle, a, presents an indentation in its cavity, and is consequently converted into the ocular cup, the inner wall, r, of which subsequently becomes the retina, the outer wall, p, becoming the pigment epi- thelium. The interior of the ocular cup communicates with the first cerebral vesicle, 6, through the optic-nerve proton, o. The projecting portion of the wall of the ocular cup is wanting below, because the foetal ocular cleft is situated here. M, mesoderm, in which, near the lower edge of the rudimentary lens, can be seen the cross section of a capillary Fig. 86.— Section through the Embryonic Eye at a Period of Development correspond- ing to that of a Human Embryo of Twenty-four to Twenty-five Days. Magnified 100 X 1. The section here depicted does not pass through the fcetal ocular cleft, so that the secondary ocular vesicle appears as a complete cup ; the more so since the portion of ectoderm, .E, representing the rudimentary lens, L^ has become invaginated further than in Fig. H5. In the bottom of the depression occupied by the lens there lies some cell detritus, and be- tween the lens and the inner wall of the ocular cup are seen a few cells derived from the mesoderm, M. In one or two spots in the mesoderm are visible the cross sections of capil- laries. 0, rudimentary optic nerve. that has been invaginated and thus, so to speak, reduplicated. From the ocular vesicle is subsequently formed the retina, which thus must be looked upon as an isolated portion of the brain itself. The exterior and interior layer of the secondary ocular vesicle become differentiated early. In Fig. 87 B, the inner layer, r, is seen to be already consider- ably thicker than the external, p, although the latter also consists of several rows of cells. The exterior layer later becomes composed of a single row of cells, takes up pigment (Fig. 88), and ultimately becomes the pigment epithelium, which therefore is rightly counted in with the retina. The interior layer (?•) soon gets to surpass the exterior one considerably in thickness, especially at the posterior portion of the eye, where its cells acquire a radial arrangement and develop into the retina proper. The anterior margin of the ocular vesicle, where the ANATOMY AND PHYSIOLOGY OF THE UVEA. 285 two layers become continuous, corresponds to the margin of the pupil in the fully developed eye (Fig. 89). At the time when the indenting of the ocular vesicle by the lens takes place, the latter completely fills the cavity of the vesicle, no vitre- ous as yet existing. This latter is essentially connective tissue, and is derived from the mesoderm, which sur- rounds the ophthalmic vesicle (Fig. 84, ^ M), and which makes its way into the ^ interior of the latter through an open- jif ing — the festal ocular cleft — in its lower ., . ••.•.; Fig. 87. —Secondary Ocular Vesicle with Ocular Fissure op the Left Eye op a Human Foetus Twenty-seven Days Old. Magnified y8 x 1. A. — Ocular vesicle seen from in front and a little below. The drawing is taken from a model which Prof. Hochstetter has made from his dissections by the plate-model method. The model represents the rudimentary brain with its processes, but omitting the ectoderm and mesoderm. The eye rises by a thick hollow pedicle from the lateral wall of the first cere- bral vesicle, G. At its distal end it presents an indentation, L, which corresponds to the invagination of the lens vesicle into the ocular vesicle. The limits of the lens vesicle are indicated by a dotted curved line. From the lower margin of the indentation runs the f cetal ocular cleft. This, at first very narrow, afterward widens .somewhat, and extends down upon the pedicle of the optic vesicle. B.— Ocular vesicle seen in vertical section. Out of the numerous sections combined to form the drawing A, the one selected for representation in B is that passing precisely through the ocular cleft; hence the lower wall of the ocular fissure is wanting here, just as it is in Fig. 8.5. The walls of the first cerebral vesicle, (?, approach each other and form the pedicle of the ocular vesicle (o, subsequently the optic nerve), and further along form the reduplicated wall of the secondary ocular vesicle. The external lamina, p, of this reduplicated wall, which later is transformed into the pigment epithelium, composed of a single layer of cells, is at this time still destitute of pigment and composed of several layers of cells. At the anterior border of the ocular vesicle it is reflected to form the thick inner lamina, r. This latter, from which the retina proper is developed, is already beginning to show a radial arrangement of nuclei. The anterior border of the ocular vesicle is covered by the ecto- derm, E, E, upon which is the rudimentary lens, L. which has already become closed so as to form a vesicle, but is not yet completely detached. Above, the mesoderm, M, fills the space between the cerebral vesicle, the ocular vesicle, and ectoderm; but below, the meso- derm, wherever the ocular cleft extends, penetrates into the interior of the ocular cup till it reaolies the lens vesicle. side. Even as early as the time when the ocular vesicle is undergoing invagination so as to form a flask, we notice that at one spot in its lower side the wall of the flask is altogether deficient (Figs. 85 and 87 B). Here, then, a fissurelike defect exists in the wall of the flask, a defect which is continued backward upon the pedicle of the ocular vesicle (the optic nerve) in the form of a furrow (Fig. 87 A). Through this fissure the mesoderm gradually grows from the outside into the interior of the eye, pushing its way in between the retina and the lens, 286 DISEASES OF THE EYE. separating them from each other, and itself becoming transformed into the vitreous. Subsequently the margins of the fissure unite so that the eye again forms a closed yesicle. The vitreous is thus cut off from its connection with the portions of the mesoderm that lie without, and which produce the uvea and the sclera. The channel in the optic nerve, which represents the continuation backward of the ocular cleft (Fig. 87 A), is also filled in by mesoder- mal tissue. When, then, the margins of this channel afterward become united in the same way as is the case with the cleft in the eyeball itself, this tissue, which is derived from the mesoderm, is shut up here, and retains none of its former connections save those existing anteriorly with its continuation, the vitreous. This tissue afterward develops into vessels running along in the eye stalk or optic nerve, which ac- cordingly incloses them. They constitute the central vessels of the optic nerve, and are continued forward into the vitreous as the vessels of the latter (Fig. 88). The vessels in the embryonic eye are, in fact, disposed as follows : The central artery of the optic nerve continues its course as the arteria centralis corporis vitrei or arteria hyaloidea (Fig. 88), through the vitreous to the posterior pole of the lens, lying in the central canal of the vitreous (canalis hyaloideus sen Cloqueti). Fur- thermore, as it enters the eye, the central artery of the optic nerve gives o£E lateral branches which form an arterial network in the periph- eral portions of the vitreous (vasa hyaloidea propria — not yet present in the eye that is represented in Fig. 88), and likewise extend forward to the margin of the lens. The arteria centralis corporis vitrei, upon arriving at the posterior pole of the lens, divides into branches, ramify- ing over the posterior surface of the lens and running forward to the margin of the latter, where the anterior extremities of the vasa hya- loidea propria unite with them and form a specially dense network of vessels surrounding the border of the lens. In front of the equator of the lens there are other branches that run to this vascular network, turning round the anterior border of the ocular cup to reach it. These are derived from that portion of the mesoderm that afterward forms the uvea. They assist in covering also the anterior capsule of the lens with a vascular network. Among the vessels derived from the uvea are found veins as well as arteries, and these uveal veins provide for the escape of all the blood, since all the other vessels going to the lens are arteries. The lens in the foetal eye is accordingly surrounded by a vascular membrane, the tunica vasculosa lentis, which in the region oc- cupied by the pupil bears the name of pupillary membrane (mem- brana pupillaris, M, Fig. 89), while its remaining portion is known as the membrana capsularis ((7, Fig. 89). The tunica vasculosa lentis disappears in the last two months before birth, although scattered rem- nants of the pupillary membrane are quite frequently found still pres- ent in newborn infants. ANATOMY AND PHYSIOLOGY OF THE UVEA. 287 The vessels of the retina develop by growing out from vessels that extend from the optic-nerve entrance out upon the inner surface of the Fig. 88.— Section through an Eye at a Period op Development Corresponding to that of A. Human Embryo in the Middle of the Third Month. Magnified 73 x 1. The envelope of the ocular vesicle is formed of mesoderm, and in its anterior segment consists of the cornea, which contains an abundance of nuclei throughout and a particularly marked accumulation of nuclei separating it from the posterior segment. In this posterior segment no delimitation between sclera and uvea has as yet taken place. The uvea will develop from the inner layers, which are distinguished by containing more nuclei— a char- acteristic which is continued over into the hindmost, or uveal, laj eis of the cornea. At a point corresponding to the anterior margin of the ocular vesicle the mesoderm projects into the interior of the eye, and from the free border of the ring-shaped process thus formed rise two delicate vascular membranes which surround the lens, constituting a sort of vascu- lar lenticular capsule. Into the hinder of these two membranes the hyaloid artery enters at a point corresponding to the posterior pole of the lens. This artery rises from the central artery, C, of the optic nerve. Of the two laminae composing the secondary ocular vesicle, the external, or pigment epithelium, has been reduced in its posterior part to a single layer of cells, while in its anterior portion there are still several cell layers present which have already taken up pigment. The inner lamina, or retina, consists of numerous layers of cells, the nuclei of wliich show a partially radial arrangement. In the immediate vicinity of the optic-nerve entrance can be seen the way in which one lamina is reflected into the other. The anterior point of reflection corresponds to what is later the pupillary margin of the iris. The lens is of an almost sphei'ical shape; its antero-posterior diameter, in fact, is actually somewhat larger than its equatorial. Upon the anterior surface of the lens lies the epithehum. which still consists of several layers of cells; and no distinct lens capsule has yet been differentiated. In the region of what is later the equator of the lens the epithelial cells are growing out into lens fibers, which are still nucleated tliroughout, and take a sagit- tal direction. The posterior surface of the lens is destitute of epithelium, and is covered by an extremely delicate capsule. The vitreous cavity is very small. X, L^, the eyelids grow- ing out. retina, while the vessels of the vitreous, previously present, undergo ob- literation. The mesoderm that envelops the ocular vesicle forms through its outer layers the cornea and sclera, and through its inner layers the uvea. The most anterior portions of the latter — i. e., the ciliary body and iris— arise from that layer of the mesoderm which, jutting out like a spur into the interior of the eye, covers the anterior, tapering portion 288 DISEASES OP THE EYE. of the wall of the vesicle (Fig. 89), which itself furnishes the inner lining for both these structures. Over the ciliary body it is only the external lamina of the ocular vesicle that is pigmented, while from the non-pigmented layer of cells constituting the internal lamina the pars ciliaris retinae is formed. Farther forward, over an area corresponding to the posterior surface of the mesodermal rudimentary iris, both lam- inae of the ocular vesicle are pigmented, and th§ two unite after under- FiG. 89.— Anterior Segment of the Eye at a Period of Development corresponding to THAT OF A Human Embryo at the End of the Third Month. Magnified 80 x 1. The epithelium of the cornea, ff, is continued over upon the conjunctiva as far as the retrotar- sal fold, U. Behind the cornea is seen the front wall of the ocular vesicle. The two laminae forming this wall are reflected so as to unite with each other at a point corresponding to the margin of the pupil. The external lamina, P, is pigmented throughout, the internal lamina being pigmented only in its anterior portion, where it later is converted into the pos- terior stratum of the retinal pigment layer of the iris. Farther back, where the inner lamina is destitute of pigment, it is afterward converted into the pars ciliaris retinae, which lines the ciliary body, and is composed of a single layer of cells. Still farther back a sud- den swelling out of the inner lamina denotes the beginning of the retina proper, r, at a spot corresponding to what is afterward the ora serrata. The two lamln£e of the ocular vesicle, so far as they constitute the coating of the ciliary body, lie closel.v applied to the mesoder- mal envelope. Farther forward, at a point corresponding to the rudimentary iris, they separate from the cornea, from which they receive a covering of mesodermal tissue, after- ward converted into the stroma of the iris. From the free border of this tissue are given off two membranes— the membrana pupillaris, il/, which passes to the opposite pupillary bor- der, and the membrana capsularis, (7, which runs backward, between ciliary body and lens, to the posterior surface of the latter. In the lens, L, the circle of nuclei is carried farther forward than in Fig. 88, and the shape of the lens in cross section has already become more elliptical. going reflection at the border of the pupil. Conjointly they form the retinal pigment layer of the iris (see pages 253, 256). The lids originate as folds, which keep growing out above and be- low the eye from the skin surrounding it, until their edges come into contact. They then become united to each other, but only by their epithelial lining ; and shortly before birth this union of the two is dis- solved again. The lachrymal gland originates from a budlike intrusion of the epithelium of the conjunctiva into the orbital tissue. The lachrymal canal starts from a channel which exists even at an early period be- tween the superior maxillary and the nasal processes. CHAPTER V. DISEASES OF THE IRIS AND OF THE CILIARY BODY. I. Inflammation. 66. The iris and the ciliary body form a continuous whole, inas- much as the iris springs from the ciliary body ; both, moreover, are supplied by the same blood-vessels. It is hence quite easy to under- stand that both organs are very frequently diseased at the same time. Unmixed inflammation of the iris (iritis) or of the ciliary body (cyclitis) is rare ; in most cases we have to do with a combination of the two (irido-cyclitis). For practical reasons, however, it is advisable first to describe the symptoms of iritis and of cyclitis separately, and then show what sort of clinical picture is produced by their combi- nation. Symptoms of Iritis. — The symptoms of iritis are partly referable to the hypersemia of the iris, partly to the formation of exudation. HypercBmia of the iris manifests itself chiefly by the discoloration which causes a blue or gray iris to appear greenish — a change which is particularly striking when comparison is made with the iris of the other eye, in case this is healthy. In dark eyes the discoloration is less pronounced. Sometimes, with the aid of a magnifying glass, we can clearly distinguish the separated dilated blood-vessels under the form of red strife or maculae. The other changes found concern the pupil, which is contracted, and does not react as well as usual. The contrac- tion is a necessary result of the dilatation of the iris due to the in- creased fullness of the vessels ; besides, there is a spasm of the sphincter produced by the irritation. For these reasons the reaction of the iris to light is diminished, and atropine also acts less promptly and less thoroughly than usual. The hypersemia of the iris is accompanied by ciliary injection, photophobia, and increase of the lachrymal secre- tion. The symptoms of congestion just described may exist by them- selves without symptoms of exudation, iu which case we do not speak of iritis, but merely of hyperemia iridis. This is observed as a result of the same causes as iritis itself, in case the irritation is not great enough to provoke actual inflammation. Pure hyperemia of the iris is most frequently seen in corneal afEections, and particularly in case 19- 289 290 DISEASES OP THE EYE. of small ulcers or foreign bodies in the cornea. Hyperasmia of the iris, provided it is not the precursor of an iritis, disappears without leaving any lasting traces of its presence. Exudation takes place partly into the tissue of the iris itself, partly into the surrounding cavities, the anterior and posterior chambers, and is accordingly characterized by varying symptoms : 1. Exudation iiito the tissue of the iris makes the latter, since it is filled with an abundance of round cells, ap- pear swollen and thicker than usual. The discoloration is still more pro- nounced than in simple hypertemia, the distinctness of the markings upon the anterior surface of the iris being ob- scured. It is easy to understand that the rigid and swollen iris should react but insufficiently to light ; the pupil is greatly contracted. 2. Exudation into the anterior chamber manifests itself first by tur- bidity of the aqueous, in which numer- ous exudation cells are suspended. The turbidity is best recognized upon the dark background of the pupil, which in this case looks gray instead of being a pure black. Gradually the formed constituents floating in the aqueous sink to the bottom of the chamber, where they produce a hypopyon (Fig- 53). When there is very great hyperse- mia, rupture of the blood-vessels in the iris may take place with an extravasa- tion of blood, which also sinks to the bottom of the anterior chamber (hy- phsema). Besides the exudates suspended in the aqueous, a layer of exudate is also found covering the walls of the anterior chamber. Hence the cornea presents a uniform delicate cloudiness. Moreover, the layer of exudate deposited upon the iris (Kg. 90) contributes essentially to the hazy appearance of the iris markings. The layer of exudate extends from the iris upon the anterior capsule of the lens (Fig. 91, «), and covers the latter throughout the area of the pupil, which consequently appears gray. If this exudate becomes organized, a membrane is produced which Iritis. Magnified 116 x 1. Upon the surface of the iris is a layer of exudate, E, consisting mainly of a fine network of coagulated fibrin, in which lie scattered pus corpuscles. The iris, J, is bounded in front by the anterior limiting layer, v, behind by the posterior limiting layer, h, and the retinal pigment layer, P. In the tissue of the iris are recognized the cross sections of blood-vessels, b, with very developed adventitia, and a great quantity of pigmented cells (the specimen is talcen from a dark-brown iris). Most of these stroma pigment cells still retain their elongated and branching shape, but others, at fc, are transformed into shapeless agglom- erations of pigment, as is usually the case in inflammation of the iris. In the anterior layers of the iris many small cells (emigrated leucocytes) — likewise an evidence of inflamma- tion—lie between the pigment cells. DISEASES OF THE IRIS AND OF THE CILIARY BODY. 291 closes the pupil and is connected with the pupillary margin of the iris (Pigs. 93 and 93, e). This is called a pupillary membrane, and the condition thus brought about is called occlusio pupillm. It is evident that this condition must result in a very considerable impairment of vision. 3. Exudation poured out into the posterior chamber is not accessible to direct observation, but manifests itself only by the adhesions which it [^^:p^^!«»j*.*pi7^i,,g5.^.i;',.;Sy^5:7:i ^:;;/>:^/';:|^^Pi ^'■■' iP Fig. 91.— Recent Iritis with Pupillary Membrane. Magnified 55 x 1. The iris, i, is greatly thickened by swelling and infiltrated by numerous round cells. Attached to the pupillary margin is an exudate, e, which fills the whole pupil, and which, on the one hand, pushes its way somewhat beneath the pigment layer, p, and, on the other hand ex- tends up on the anterior surface of the iris. That it is a quite recent exudate is evident from its thickness and from its being composed of a network of fibrin, inclosing scattered pus corpuscles. The number of the latter increases toward the surface of the iris Fig. 92.— Occlusio Pupille Two Months after a Perforating Injury. Magnified 55 x 1. The exudate, e, has become converted into connective tissue, and has, in consequence shriveled down to a thin pellicle, which, becoming constantly more and more attenuated can be traced over the entire surface of the iris. The iris itself has become thinner from atrophy and where it ends at the pupillary margin is tapered oft owing to its being pulled upon by the pupillary membrane. The pigment layer, p, is the part most drawn out into the pupil so that it projects a good bit beyond the sphincter, s, and the stroma of the iris i Hence the margin of the pupil in the living eye, when looked at from in front, seems as though encompassed by a broad brown rim, which appears to attach the edge of the pupil to the capsule of the lens. Fig. 93. — Occlusio Pupill.^: Three Months after a Perforating Injury. Magnified 55 x 1. The exudate, e, is converted into a thin membrane of connective tissue, which, at the pupillary border of the iris, extends [somewhat over upon, but] mainly beneath the latter, and can be traced as a delicate pellicle for a long distance between the pigment layer, p, and the lens capsule, k. The tension set up by the pupillary membrane upon the border of the atrophic iris, i, has drawn the latter down over the pigment layer, so that the sphincter iridis, s, which is solidly united with the pigment layer, has its anterior border turned back in a hook-shaped bend. In the living eye the margin of the pupil appeared encompassed by a gray rim, which merged gradually into the less gray, because more transparent, pupillary membrane. causes between the iris and the capsule of the lens (posterior synechia). These adhesions develop principally at the spot where the iris and the capsule of the lens are in contact — i. e., at the pupillary margin. They form at the time when the iritis is at its height, and when, there- fore, the pupil is greatly contracted. When, after the iritis has run its course, the pupil tends to resume its usual mean width, this is only 292 DISEASES OP THE BYE. possible over the area in which the pupillary margin has remained un- attached. The portions that are adherent to the capsule of the lens (au not retract, but remain as tags of greater or less size, projecting in toward the center of the pupil. The pupil thus acquires an irregular shape which is still more obvious if atropine is instilled ; for, as the iris then retracts strongly at its unattached portions, the synechia stand out in the clearest possible way (a and h. Fig. 94). Atropine is hence a very valuable agent for the diagnosis of posterior synechia. In the formation of posterior synechise, it is not the stroma of the iris, but the layer of retinal pigment (Figs. 91, 92, and 93, p) covering its posterior surface, that becomes adherent to the capsule of the lens. When the iris starts to retract, the pigment layer is held back at the points of adhesion, and is thus exposed to view more extensively than usual. Hence in dilatation of the pupil, especially by atropine, the Fig. 94.— Postbbiob SYNECHi.ffi: and the Remains of a Pupillary Membrane. Magnified 2x1. The pupil has been dilated by the instillation of atropine. The dilatation, however, is unequal, because the upper part of the pupillary margin is fixed by means of adhesions to the an- terior capsule of the lens. At a there is a slender synechia which is drawn out into a fine black point ; at fo, on the other hand, is found a broad and but slightly elongated adhesion, such as frequently occur, especially in syphilitic iritis. Between the synechiae and by the side of them, the capsule of the lens is covered with minute black dots arranged in a semi- circle. They correspond to the situation of the pupillary margin when the pupil was con- tracted and have been left by the rupture of the adhesions. From the lower part of the iris a filament, c, runs straight upward. This arises from the trabeculse of the cii-culus iridis minor, and passes in the region of the pupil to the anterior capsule of the lens, where it is attached to a small, round, capsular opacity. This filament is not a posterior synechia, but a remnant of the foetal pupillary membrane. It does not prevent the iris from' retract- ing properly under atropine, but is simply stretched and drawn out thin itself. tags jutting out into the pupil look brown. From the traction exerted by the iris, rupture of the synechise may result. This some- times is effected spontaneously by the traction which is constantly being made upon the adhesions during the ceaseless movements of the iris ; for the most part, however, rupture is produced artificially by the instillation of atropine. In that case we see, at the spot where the synechia has been set free, a brown spot remaining upon the anterior capsule of the lens. This is the pigment layer whose pathological adhesion to the capsule of the lens is firmer than its physiological con- nection with the tissue of the iris. If several synechia have been ruptured, we find remains of them in the shape of a corresponding number of brown dots arranged in a circle upon the anterior capsule of the lens (Fig. 94, between and on either side of a and h). This circle is narrower than the mean diameter of the pupil, because the Gynechise were formed at the time when the pupil was contracted by DISEASES OF THE IRIS AND OP THE CILIARY BODY. 293 iritis. The dots of pigment never disapi^ear, and hence during the whole life give evidence of an iritis that has once existed. If the adhesion of the iris to the capsule of the lens is not confined to single points, but comprises the whole extent of the pupillary mar- gin, we speak of an annular posterior synechia. No projecting tags are then apparent, because the iris is no longer able to retract at any spot, the pupil remaining unchanged all the time, even after the in- stillation of atropine. There is generally a brown rim (pigment) or a gray rim (exudate) investing the pupillary margin (Figs. 93 and 93). An annular synechia is seldom formed all at once ; it is for the most part the result of a number of recurring attacks of iritis, which little by little produce a more and more extensive adhesion of the iris to the lens. The direct consequence of an annular synechia is the shutting off of the anterior from the posterior chamber — shutting off of the pupil {seclusio pupillcB, Fig. 97). The two sequelas of iritis, shutting off of the pupil (seclusio pupil- lae) and shutting up of the pupil (occlusio pupills), very often occur to- gether owing to the fact that the exudate which attaches the pupillary margin to the lens may also extend over the entire pupil. But they may also occur separately and then have very different consequences. Occlusion of the pupil occurring by itself produces very great diminu- tion of sight, without, however, entailing any dangers for the future. Seclusion of the pupil in itself does not affect the sight, if the pupil ia free from membrane, but subsequently induces changes (increase of tension) which cause blinding of the eye. 67. Symptoms of Cyclitis. — Exudation from the ciliary body, apart from the infiltration of the tissue itself, takes place into the anterior chamber, the posterior chamber, and the vitreous : 1. The exudate produced by the ciliary body can get into the anterior cliamber in two ways: either directly, in case there is implica- tion of the most anterior portion of the ciliary body — i. e., that covered by the ligamentum pectinatum and lying at the confines of the anterior chamber; or indirectly, from the exudate being deposited first in the posterior chamber and then carried along with the aqueous through the pupil into the anterior chamber. A form of exudate that is found in many, especially the chronic cases of inflammation of the ciliary body, are Xh^ precipitates (deposits) upon the posterior surface of the cornea. These are small dots, no bigger than a pin's head, of a light gray or brownish color, which lie upon the posterior corneal surface {p. Fig. 97). They were formerly thought to be located in the cornea itself ; but if by puncturing the cornea the aqueous is allowed to escape, some of the deposits may be seen to disappear too, being swept away with the aqueous — a proof that they simply lie upon the posterior surface of the cornea. If the deposits are large, but few of them are generally present, and they are 294 DISEASES OP THE BYE. then commonly scattered irregularly over the cornea (Fig. 96 A). The smaller the deposits, the more numerous they generally are. They then occupy the lower half of the cornea, in which they cover a surface having the shape of a triangle. The base of the triangle cor- responds to the lower corneal margin, and its apex is directed upward Fig. 95.— Irtdo-ctclitis after Perforatino Injory. Magnified .30 x 1. In the drawing only a part of the anterior division of the eyeball ia represented. The cornea, C, and the sclera, S, are unchanged. Owirg to the fact that the aqueous is rich in fibrin, and hence is coagulated by the hardening fluids used, the anterior chamber. K, is filled with a dense network of fibrin, in which lie isolated round cells (emigrated white blood-corpus- cles). These round cells are particularly numerous upon the surface of the iris, and a-bove all in the sinus of the chamber; in fact, they fill the sinus completely, and form in it a low hypopyon which was visible in the living eye. A marked cellular infiltration can be seen surrounding Schlemm's canal and the cross sections of tlie anterior ciliary veins situated above the canal. The iris. I, appears broadened, as seen in cross section, this appearance corresponding with the swelling which existed in the living eye. Its vessels are dilated, and are distended with blood. In its stroma, particularly in the posterior layers, round cells are visible in great numbers : its retinal pigment layer is broadened and relaxed. The greatest emigration of cells has taken place from the blood-vessels of the ciliary body, the direction pursued being a centripetal one — i. e., toward the interior of the eye. Hence the infiltration in the ciliary muscle, M, is but slight, in the ciliary processes. P, it is rather more pro- nounced, and upon the surface of the latter it is the most marked of all, so that the outer limits of the processes are concealed by the dense masses of cells. The hyaloid membrane, H. is pressed away by the exudate from the surface of the ciliary body. The contents of the posterior chamber, like those of the anterior, are formed of a fine network of fibrin with round cells imbedded in it, these latter being found in specially large numbers along the hyaloid membrane. Two of the groups of fibers composing the zonule of Zinn are seen under the form of bright bands, passing through the coagulated contents of the posterior chamber to the lens, L. The latter displays the epithelium of its anterior capsule and the nuclear ring, and shows no morbid change. toward the center of the cornea. It is frequently observed that the deposits diminish in size from the base toward the apex of the triangle (Fig. 96 B). The peculiar arrangement of the deposits is readily explained by their mode of origin. The deposits are conglomerations of cells, DISEASES OP THE lEIS AND OP THE CILIARY BODY. 295 agglutinated into masses by means of fibrin (Fig. 99). At first they are suspended in the aqueous, and by the movements of the eye are thrown by virtue of centrifugal force against the posterior surface of Fig. 96A. — Precipitates. Besides minute deposits, there are found also large ones, which are light gray and larda- ceous-Iooking. '. — Precipitates. These are small and disposed in the form of a triangle. the cornea and adhere to it. In so doing they arrange themselves according to weight, the largest being lowest down. The triangular shape of the arrangement is a result of the movements of the eyeball, by which the deposits are cast upon the cornea. We have only to think of what happens when we throw sand through a wire screen or shake grain in a sieve. The little fragments of stone or of grain always form a pointed figure with the apex, which contains the finest particles, running upward, while successively coarser particles follow in Tc r . Fig. 97.— Seclusion .and Occlusion of the Pupil. Magnified 5x1. The iris is adherent by its entire pupillary margin to the lens, but elsewhere is pushed forward. The posterior chamber, h, is thus made deeper, the anterior chamber, r. shallower, espe- cially at the periphery where the root of the iris, a, is pressed against the cornea by the increase of tension. In consequence of the traction made upon the iris, its retinal pigment is beginning to separate (at s) and to be left upon the capsule of the lens. The pupil is closed by an exudate membrane, o, by the shrinking of which the anterior capsule is throWn into folds. In the lower part of the anterior chamber there is matter, p, precipitated upon the posterior surface of the cornea. In consequence of the increase in tension, both the ciliary processes, c, and the ciliarj^ muscle, m, are atrophic nnd flattened. The cortex of the lens has undergone cataractous disintegration, and at r is separated from the capsule by liquor Morgagni ; the nucleus, fc, of the lens is unaltered. order below. The same is the case with the deposits. By their peculiar arrangement the deposits are generally easily distinguishable from macular opacities in the cornea itself (in keratitis punctata, see 296 DISEASES OF THE EYE. pages 184 and 193). Other distinguishing marks are the dearer out- line and frequently the brownish color of the deposits, which, more- over, do not lie at different depths like maculae in the cornea itself, but lie all in the same plane — that is, on the posterior surface of the cornea. That the deposits actually originate in the ciliary body and not in the iris is proved by the cases of pure cyclitis, in which deposits are present in abundance, although all symptoms of inflammation on the part of the iris are wanting. The exudate from the ciliary body, deposited in the anterior cham- ber, may also appear there under the form of hypopyon, just as in iritis. But what particularly characterizes cyclitis are the gray or grayish- white exudates that develop in many cases and which appear to grow out in the form of spongy masses from the sinus of the chamber, and that not merely, below, but also from other directions. 2. In consonance with the anatomical situation of the ciliary body, the great mass of the exudate is deposited in the posterior cham- Fio. 98.— Total Posterior Synechia. Vertical Suction THRonoH the Eye. Maguifled B x 1. The iris is adherent by its poaterior surface to the anterior capsule of the lens and also to the anterior surface of the ciliary body. The posterior chamber consequently is obliterated and the anterior chamber deepened at its periphery. 6 ; at this spot the iris is strongly re- tracted and at the same time is here the most thinned through atrophy. The exudate con- necting the iris with the lens also stretches as a thin membrane, p, across the pupil. The hull of exudate, a, springing from the ciliary body, envelops the posterior surface of the lens and by its shrinking draws the ciliary processes toward the center. As a result of this, a separation of the ciliary body, c, from its bed has already taken place below, and in the intermediate space are seen the disjoined lamelte of the suprachorloid membrane, a. The pigment epithelium, /, of the ciliary processes has undergone proliferation. At tlie lower parp of the cornea there is a zonular opacity, g. The lens is swollen and is opaque through- out ; there Is no hard, undisintegrated nucleus (i. e., it is a soft cataract). ber. This exudation, if extensive, leads to the adhesion of the whole posterior surface of the iris to the anterior capsule of the lens {total posterior synechia, Fig. 98). This adhesion of the surface of the iris is distinguished from the annular synechia, in which only the pupillary border of the iris is attached to the capsule, chiefly from the altered DISEASES OF THE IRIS AND OP THE CILIARY BODY. 297 form of the anterior chamber. The exudate, as it shrinks, draws the iris everywhere up to the anterior surface of the lens, so that the pos- terior chamber is completely obliterated. The anterior chamber is hence proportionately deeper, above all at the periphery, where the iris is displaced farthest backward {I, Fig. 98). 3. Exudation into the vitreous appears under the form of opacities of the vitreous, which can be made out with the ophthalmoscope if the condition of the refracting media jDermits. Moreover, they mani- fest themselves by a corresponding diminution of the vision. In severe cases, an exudation of large size exists in the anterior division of the vitreous (s, Fig. 98), and under favorable circumstances can be seen with lateral illumination as a gray mass behind the lens. The sight is then almost completely abolished, and atrophy of the whole eye is subsequently produced by the shrinking of this mass of exudation. The tension of the eye, which in iritis is usually unchanged, often shows an alteration in cyclitis. It is not infrequently found to be ele- vated in the beginning of the cyclitis ; indeed, such a great elevation of tension may be developed that blindness is produced by it. In the later stages of cyclitis, on the contrary, diminution of the intra-ocular pressure is more frequent, and is the result of the shrinking of the exudate while in process of organization. Both iritis and cyclitis are associated with symptoms of inflamma- tory irritation, consisting of ciliary injection, photophobia, lachryma- tion, and pain. The pain is not only situated in the eye itself, but radiates to the parts in the vicinity, especially the supra-orbital region. The intensity of the irritative symptoms is regulated by the greater or less acuteness with which the case runs its course. Chronic cases occur in which inflammatory symptoms are wanting altogether, so that the eye is at no time reddened or painful ; on the other hand, there are cases of irido-cyclitis in which the pain reaches an absolutely intoler- able pitch and is associated with vomiting and a febrile movement. Sometimes the pain sets in with special violence at night (particularly in syphilitic iritis and irido-cyclitis). Vision is always diminished through turbidity of the aqueous or through exudation in the region of the pupil or in the cavity of the vitreous. Differential Diagnosis between Iritis and Cyclitis.— We speak of iritis if the symptoms enumerated above are present, and there is no direct proof of the participation of the ciliary body in the inflamma- tion. That the ciliary body is pathologically altered in most cases of apparently simple iritis is put beyond a doubt by anatomical investi- gations. But, since we can not see the ciliary body directly, slight changes in it escape diagnosis. We hence make the diagnosis of irido- cyclitis only in those cases in which in addition to the symptoms of 298 DISEASES OP THE EYE. iritis positive evidences of involvement of the ciliary body are also present. This is the case — 1. When the inflammatory symptoms reach a considerable pitch, and especially if oedema of the upper lid is associated with them — a thing which does not occur in simple iritis. 3. When the eyeball in the ciliary region is painful to the touch. 3. When deposits are present upon the cornea, or when the marked retraction of the periphery of the iris leads us to infer the existence of a total posterior synechia. 4. When the disturbance of vision is more considerable than one would expect from the opacities within the confines of the anterior chamber. We are then justified in inferring the existence of opacities in the vitreous causing diminution of vision. 5. If the tension is altered — either elevated or lowered. The participation of the ciliary body in the inflammation of the iris makes the disease a far more serious one and renders the prognosis worse. Not only is the . inflammation more violent, but it induces changes which are much more difiicult to remedy. The exudates, such as posterior synechias and pupillary membranes, produced by iritis in the confines of the anterior chamber, may be attacked successfully by operative procedures. But the exudates left by cyclitis in the vitre- ous, so far as they do not become absorbed spontaneously, are in no way susceptible of removal. Severe cyclitis leads to destruction of the eye (atrophy of the eyeball) — a thing that never occurs with iritis alone. Simple cyclitis * without iritis occurs but seldom, and that only in the chronic form. The infiammatory symptoms are slight or absent, the iris is of normal appearance, and the pupil is generally somewhat dilated. The chief symptoms are the presence of deposits upon the cornea and opacities in the vitreous. Inexperienced physicians often fail to recognize slight cases of iritis, con- sidering it as catarrh on account of the injection of the eyeball that coexists with it. The treatment then employed, such as the application of the silver- nitrate solution or the instillation of irritating collyria, commonly aggravates the iritis. We can avoid this mistake if in every case we pay careful attention to any discoloration that there may be in the iris (particularly by comparing it with that of the other eye), and also to the dimensions of the pupil, which in an eye with iritis is contracted. Moreover, a slight turbidity of the aqueous can be recognized, even in the early stages, from the fact that the pupil has not the same pure black look as in the other eye. On the other hand, the mis- take is often made of considering an inflammatory glaucoma as an iritis on ac- count of the ciliary injection and the discoloration of the iris — a mistake which is the more disastrous because in glaucoma great harm is done by the instilla- tion of atropine. Here, besides the testing of the tension, our chief means of * The serous iritis of authors. DISEASES op THE IRIS AND OP THE CILIARY BODY. 299 guarding against mistakes is the examination of the pupil, which in iritis is always more contracted, in glaucoma always more dilated, than usual. In recent acute iritis and irido-cyclitis examination of the sight discloses sometimes the existence of a moderate degree of myop'ta, which did not exist previous to the inflammation, and which, moreover, gradually disappears again after the latter has run its course. A peculiar appearance is furnished by the presence of a pretty large /&?•«- nous exudate in the anterior chamber, such as is at times observed in every sort of acute iritis. If, for example, much fibrin is deposited in the aqueous, it may become coagulated into a uniformly gray, translucent mass (hence the name gelatinous exudate and also lenticular exudate, because with its rounded edges it sometimes looks like a half-transparent lens that has been dislocated into the anterior chamber). The exudate speedily shrinks, since the fibrin in contracting expels the liquid from its meshes (for which reason we also speak of it as a spongy exudate).* After a few days the exudate has either com- pletely disappeared or it has been reduced to a thin pellicle lying in the pupil and often still connected with the pupillary margin by one or two slender filaments. It happens sometimes that posterior synechife develop in the presence of a dilated, instead of contracted, pupil; as, for example, when they form in an eye under the infiuence of atropine. In this case the margin of the pupil becomes adherent to the capsule of the lens at some peripherally located spot, so that afterward, when the pupil assumes its mean width, the synechia is marked, not by a projecting process, but by a re-entrant angle. Por the diagnosis of seclusio pupillcB, the employment of atropine is indis- pensable. It often happens that the pupillary margin is thought to be adher- ent to the capsule all round, when, nevertheless, upon the employment of atro- pine it retracts at one small spot. At this unattached portion, which is most frequently situated above, there is thus formed a curved or horseshoe-shaped indentation of the pupillary margin. Similarly we may infer the existence of a small opening if, after the case has been under observation for a longtime, no protrusion of the iris takes place, since in true seclusio pujiillae such protrusion never fails to appear. Of course, we must be able to exclude the existence of a total posterior synechia, in which case evidently protrusion of the iris could not take place. Seclusio pupillse appears to occur frequently without, there being any simul- taneous formation of membrane in the pupil (occlusio pupillse). This, how- ever, is only apparent, as a rule. Upon careful examination we usually notice that the gray fringe of exudate which runs along the adherent pupillary margin projects far into the pupil, becoming gradually thinner as it does so, so that perhaps only the center of the pupil appears to be quite free. Nay more, if, after performing an iridectomy, we compare the pupil with the pure black colo- boma, we can almost always convince ourselves that really no part of the pupil is quite free from a membrane. Much more frequently than seclusion without occlusion, the converse— i. e., occlusion without seclusion— occurs. That is, there is a membrane in the pupil, and sometimes quite a thick one, which is not connected with the pupillary margin all round, but only at separate spots. [* Iritis associated with this sort of exudate is often called spongy iritis.— T).'\ 300 DISEASES OF THE BYE. The presence of a well-marked reaction of the pupil to light is not altogethei" conclusive evidence against the existence of seclusio pupillse. If the tissue of the iris is not yet atrophic, and a fair perception of light at the same time exists, the anterior layers of the iris, when the illumination is varied, move quite per- ceptibly over the fixed posterior pigment layer. The deposits upon the posterior surface of the cornea are easily overlooked, because they are often so excessively minute. We should, therefore, in every case in which there is a suspicion of the existence of an affection of the uveal tract, look for them with a strong magnifying glass. In doing this we may in rare cases discover deposits upon the iris also and, within the pupillary area, upon the anterior capsule of the lens as well. Deposits are found not only in affections of the ciliary body, but sometimes also in those of the most anterior sections of the chorioid. I have quite frequently found minute deposits in eyes in which a soft cataract had been operated upon by discission, and was consequently swelling up and un- dergoing absorption at the time. These so-called lens dejjosits are, however, essentially different from the genuine deposits ; they are not agglomerations of exudation, but small rounded lens fragments, detached from the swelling lens and thrown against the posterior surface of the cornea, to which they then ad- here. They are therefore in no sense to be regarded as a sign of inflammation ; and this view of their nature is confirmed by the favorable course that sucli cases pursue. Other evidences of infiammation were wanting, and the subse- quent course in these cases furthermore was favorable. In severe cases of irido-cyclitis Cespecially of sympathetic origin) tlanching of the cilia on the lids of the affected eye is sometimes observed. Results of Anatomical Examination in Ikido-ctclitis. — Exudation into the tissue of the iris is characterized by the presence of numerous round cells in the latter, the quantity of which increases with the intensity of the inflamma- tion. Often they are not distributed everywhere alike, but collect in certain spots, especially along the vessels, so that circumscribed nodules of exudation are produced. This state of things is most strongly marked in syphilitic in- flammation, in which the nodules are often so large that they can be seen with the naked eye (papulse iridis). Within the ciliary body the cellular inflltration is much more profuse in the vascular ciliary processes than in the ciliary muscle (Fig. 95). The free exudate, deposited in the anterior chamber, in part sinks to the bottom of the chamber and forms a hypopyon, in part attaches itself to the walls of the chamber — that is, to the cornea, the iris, and the capsule of the lens. The thin coating of exudate, which covers the posterior surface of the cornea (Pig. 99, h and/), causes the latter in recent cases of iritis to appear slightly and uniformly clouded. It generally disappears with the subsidence of the in- flammation ; only in rare cases is the layer of exudation so considerable (espe- cially in the lower half of the cornea) that it afterward becomes organized and leads to the production of a lasting opacity of the cornea. The deposits are conglomerations of round cells many of which contain pig- ment granules (P, Fig. 99), thus proving their derivation from the uvea. They lie upon the endothelium of Descemet's membrane, which, at first, is perfectly normal and not till afterward becomes destroyed beneath the aggregations formed by the cells of the deposit (e, Fig. 99). The endothelium, therefore, has no more to do with taking an active part in the formation of the deposit DISEASES OF THE IRIS AND OP THE CILIARY BODY. 30I than any other part of the cornea. Accordingly, the terms formerly employed to designate the deposits, such as keratitis punctata, descemetitis, aquacapsulitis hydromeningitis,* which impute their place of origin to the cornea and more particularly to Descemet's membrane, are inapplicable. After lasting for some time the cells of the deposit undergo fatty degeneration and are absorbed while the pigment granules are left behind. Hence many deposits are seen to take on little by little a darker color until at length nothing but minute black specks are left at the place where they were situated. In many cases of irido-cyclitis, particularly those that are chronic, there are found specially large, gray, lardaceous-looking deposits, which as the disease progresses change their shape, enlarge, and coalesce with neighboring deposits to form biscuit- or trefoil-shaped masses of exudation (Pig. 96 A). Here, in contradistinction to the conglomerations of exudate that simply adhere to the P Fio. 99.— Deposit upon the Postekiok Sukpace of the Cornea. Magnified 140 x 1. ™'^t?°?'*'""'' ™''f^'^<' of the cornea, C, is covered by Descemet's membrane, D. and the endo- thelium, e. The latter, which as a whole is of normal character, is wanting at the snot where the deposit, P, is situated. This deposit forms an accumulation of cells with inter- spersed pigment granules which are partly free and partly inclosed in the round cells In the place where no deposits are situated the posterior surface of the cornea is covered by a layer of exudation consisting of two strata, an anterior one, 6, composed of round cells and a posterior one, /, formed of coagulated fibrin. cornea, we have to do with independent foci of inflammation, in which, more- over, bacteria have been demonstrated to exist (Snellen the younger). The exudate that is poured out upon the anterior mrf ace of the iris displaces the endothelial membrane present there. The fate of this exudate depends upon its character. In the lighter cases, in which it consists chiefly of coagulated fibrin with only a few round cells (Fig. 90), it disappears comijletely by resorp- tion. In severe cases, the exudate is richer in cells and subsequently becomes organized. We then find the iris atrojihic and covered by a thin membrane of connective tissue (Pig. 93). The same is true of the exudation deposited upon the anterior capsule in the pupillary area, and of the exudates in tlie posterior chamber and in the cavity of the vitreous; in the light cases they are absorbed, in the severe ones they become organized into membranes, as will be more pre- cisely described in treating of the different modes of termination of irido- cyclitis. An anatomical classijication of irido-cyclitis has been based upon the varying anatomical characters of the exudate. In general, the exudates which are very poor in cells and are incapable of undergoing organization are called serous, those which are rich in cells and lead to the formation of adhesions and of * Descemet's membrane was r-alled capsula aquie, or, in Greek, hydromeninx, he- cause it was supposed to secrete the aqueous humor. 302 DISEASES OF THE EYE. membranes are called plastic. Purulent exudates are those which contain very numerous cells with a fluid intercellular substance. Nevertheless, to classify irido-cyclitis, upon the basis of diflferences of this sort, into a serous, a plastic, and a purulent variety, is a procedure that has its difficulties and can not be carried out rigorously. In the first place, several kinds of exudation are often present at the same time; for instance, a purulent exudation constituting a hypopyon, and a plastic exudation forming synechise and pupillary membranes. In the second place, the macroscopic appearance of an exudation is by no means indicative of its pathological significance. This is particularly the case with regard to pus. Purulent iritis — i. e., iritis with hypopyon — which we so fre- quently find in connection with a corneal ulcer or with a foreign body im- planted in the cornea, often runs a very mild course and one devoid of ill con- sequences. We know, however, that the pus of such a hypopyon is free from micro-organisms. A very different significance, on the other hand, attaches to a purulent exudate containing cocci, which develops after the entrance of an infecting foreign body and causes destruction of the eye. A term to be alto- gether rejected is that of serous iritis, which is used by authors for those cases in which deposits are present while synechite are absent. The deposits, how- ever, are certainly not serous exudates, and, anyway, these cases are to be looked upon as examples of cyclitis, not of iritis. Because of all these reasons, it seems to me better to classify irido-cyclitis, not according to the kind of ex- udation, but according to the etiology, as will be done later on. In irido-cyclitis, the microscope generally establishes the fact of a partici- pation of the deep parts of the eye in the inflammation. The chorioid suffers the most injury, so that, when evident signs of its implication are present, we speak of irido-chorioiditis. But the retina too and the optic disk are almost never free from pathological changes in irido-cyclitis, although these changes are often too insigniflcant to be demonstrable by clinical examination alone. 68. Course and Termination of Iritis and Cyclitis.— With regard to the course, a distinction is made between acute and chronic cases. The former are associated with marked inflammatory symptoms, but run a quicker course. But even in the acute cases — if we except the very lightest ones — it takes four weeks or more before the inflamma- tion entirely subsides. The first signs of a change for the better in the inflammation are the decrease of the injection and of the pain, and especially the prompt action of atropine, while at the acme of the in- flammation the pupil is so spasmodically contracted tliat atropine has little or no effect. Chronic cases run their course with few or absolutely no symptoms of inflammation. The patients, in the latter case, become aware of the existence of their trouble only at a comparatively late period, and then only from the increasing disturbance of vision. Chronic iritis (irido- cyclitis and irido-chorioiditis) is not infrequently protracted over a course of years. Inflammations of the iris and of the ciliary body often show a great tendency to relapse. Formerly the chief cause for the recurrence of the inflammation was supposed to lie in the posterior synechiae left by DISEASES OP THE IRIS AND OP THE CILIAEY BODY. 303 the first attack of iritis. It was believed that in the constant movement of the pupil traction was contimially made upon the iris at the places of adhesion, and thus a new source of inflammatory irritation was pro- vided. But it has been demonstrated that relapses are to be appre- hended only in certain cases of posterior synechia. If, for instance, anybody has had an ulcer of the cornea, and, as a result of it, an iritis from which there are some synechias remaining, he need never fear having a relapse of his iritis. But another man who has got synechias as the result of an iritis with a constitutional basis (e. g., a syphilitic or rheumatic iritis) can very readily have recurrences. We hence con- clude that what produces the recurrences is not the synechias, but the continuance of the same constitutional cause that was accountable for the first attack of iritis ; and, as a matter of fact, we sometimes see a syphilitic patient sufEering from a recurrence of his iritis even when the first attack has got well without leaving any synechias ; or we see a recurrence affecting, not the eye that was previously diseased, but the other eye which has hitherto been sound. The recognition of the fact that one or two synechias are in themselves of no great significance has had an important practical result : the numerous operative methods designed for the. division of synechias have now been entirely given up. Kecurrences of iritis are often less severe than the primary inflam- mation ; but, as they are pretty frequently repeated, and as they leave a new exudate after them each time, they ultimately lead to serious changes, such as seelusio and occlusio pupillse. The outcome of inflammation may be a perfect cure in light cases. The synechias rupture, leaving behind bits of pigment attached to the anterior capsule, which are unproductive of injury to the eye. The hypopyon disappears by resorption. The deposits generally persist for a long time (for mouths), until they also are removed by resorption. In many cases they leave at the spot where they were situated a perma- nent opacity of the cornea in the shape of a gray speck, or the pigment that is contained in them remains permanently as a black dot. Slight opacities of the vitreous may also disappear completely by resorption. In most cases, however, permanent sequelm remain after iritis and cyclitis. These are — 1. Atrophy of the /m.— This rarely develops after a single attack of acute iritis ; generally it is the result of repeated recurrences or of chronic inflammation. It is characterized by a bleached-out, gray, or grayish-brown aspect of the iris (resembling gray felt or blotting paper) ; the delicate markings of the anterior surface have disappeared, and in their stead dilated vessels can often be recognized as reddish blotches upon the iris. The pupillary margin is thinned down, often looking as if it had been frayed out ; the reaction of the iris is dimin- ished or altogether lost. The great friability of the atrophic iris often renders the correct performance of iridectomy impossible. 304 DISEASES OF THE EYE. The most frequent and important sequelae are the exudates and ad- hesions which remain after nearly every case of iritis or irido-cyclitis. Among these are — 2. Posterior SynecMm. — These, if only a few are present, cause no special injury to the eye, and also produce little or no impairment of sight Very much worse is the annular posterior synechia or seclusio pupillm. By this the communication between the anterior and the posterior chamber is obliterated. The aqueous secreted by the ciliary processes can no longer pass through the pupil into the anterior cham- ber ; it hence collects in the posterior chamber, pressing the iris for- ward (Pig. 97). A hump-shaped protrusion of the iris is thus pro- duced, which finally reaches as far forward as the cornea, while the pupil is represented by a crater-shaped retraction of the pupillary mar- gin which is attached to, the lens capsule. In consequence of being so greatly stretched, the iris becomes, atrophic. To this condition eleva- tion of the intra-ocular pressure (secondary glaucoma ; see § 86) is added. The increased hardness of the eye can be established by palpa- tion ; the anterior ciliary veins are dilated ; the cornea is dull and less sensitive to touch ; the sight fails, with a decrease in the field of vision starting from the nasal side, until at length the perception of light is entirely abolished. Then the formation of scleral ectasiae takes place in the blinded eye in the shape of anterior and equatorial staphylomata of the sclera. Seclusio pupillse, accordingly, if it is not remedied in time, infallibly leads to blindness. 3. Pupillary Membrane {Occlusio Pupillm). — This causes an inter- ference with vision, the degree of which depends upon the thickness of the membrane. 4. Exudates lehind the Iris. — These lie either between the iris and the lens (total posterior synechia) or between the ciliary body and the lens and upon the posterior surface of the latter. In severe cases they form a coherent fibrous mass which completely envelops the lens, and which, on account of its solidity, is called the cyclitic hull (s. Fig. 98). This has a great tendency to shrink. In total posterior synechia there is evidently no hump-shaped protrusion of the iris — on the contrary, the anterior chamber in the beginning is unusually deep at the periphery owing to the retraction of the iris (5, Fig. 98). Afterward, when atro- phy of the eye sets in, the anterior chamber often becomes shallower again, because iris and lens together are pushed forward. The exu- dates which lie behind the lens in the vitreous (c, Pig. 100) cause by their contraction a diminution of volume of the vitreous; the eyeball then becomes softer. The shrinking of the vitreous {g. Pig. 100) results in detachment of the retina (r) from the chorioid ; in part also this detachment is produced by direct traction, since the hull of cyclitic membranes as it shrinks attaches itself to the inner surface of the retina and draws it out of its bed. In consequence of the detachment DISEASES OF THE IBIS AND OF THE CILIARY BODY. 305 of the retina, complete blindness ensues. This state of things, consist- ing of diminished tension of the eyeball, with decrease ia its size and with complete blindness, is known as atrophy of the eyeball. An atro- phic eyeball presents the following picture : The whole eye is smaller and of slightly quadrangular shape. This is because the four recti muscles, stretching across the equator of the eyeball, press the sclera in somewhat at this spot, and hence produce flattening at the four sides. With the higher degrees of atrophy quite deep furrows are formed, so that the eyeball has the form of a bale of goods grooved by the cord with which it is tied. The cornea is smaller, often opaque and flattened ; at FiQ. 100.— Atrophy of the Eyeball. (In part after Wedl-Bock.) The eye is smaller and of irregular shape, chiefly from the wrinkling of the sclera. S, behind the points of attachment of the ocular muscles, the rectus internus, ?■/, and the rectus externus, re. The cornea, C, is diminished in size, flattened, and wrinkled especially on its posterior surface. At its inner border it bears the depressed cicatrix, JV, which was produced by the in.iury. The anterior chamber is shallow ; the iris, ?, is thickened and forms an unbroken surface, because the pupil is closed by exudate. Behind the iris lies the shrunken lens, /, and behind this is the great hull of 'cyclitic membrane, c, the shrinking of which is the cause of the atropb.y of the eyeball. By reason of this shrinking, the ciliary processes, the pigment layer of which has markedly proliferated, are drawn in toward the center, and, together with the adjacent chorioid, c/l, are detached from the sclera ; between the two structures are seen the disjoined lamellae of the supi'achorioid membrane, a. The retina, r, is detached and folded in the form of a funnel, which incloses the remains of the degen- erated vitreous. The subretinal space, s, is filled with a fluid rich in albumin. The optic nerve, o, is thinner than usual and atrophic. other times, again, transparent, but abnormally protuberant or thrown into folds. The atrophic iris is either pressed quite against the pos- terior surface of the cornea, or an anterior chamber still exists. In the latter case, we find the chamber bounded behind by a firm dia- phragm in which the iris, which is imbedded in the hull of exudate, is often but indistinctly recognizable. If the pupil is still distin- guishable, a membrane and the opaque lens are found in it. The eye is softer, and is often sensitive to the touch. In the later stages 20 306 DISEASES OF THE BYE. markedly hard spots (ossified exudates) may sometimes be felt through the sclera. Atrophy develops gradually through a course of months and years. The inflammation and the pain, which have been present for a long time, disappear when the atrophy is complete. But even then sec- ondary attacks of pain occur, especially if the eye harbors a foreign body, or if ossification of the exudate takes place. 5. Opacity of the Lens. — This develops in consequence of the dis- turbed nutrition of the lens. If merely a few synechise are present, it is rarely observed ; on the other hand, it is observed with proportion- ately great regularity when seclusio pupillse has existed for a long time, and particularly so in those severe cases in which the lens is completely swathed in cyclitio exudates. Such a cataract is denoted by the name of cataracta complicata or cataracta accreta (= grown fast to — i. e., grown fast to the iris). In atrophic eyeballs the lens is always opaque, and generally shrunken as well. Atrophy of the iris can progress to such an extent that the iris becomes transparent, or even so far that complete gaps form in it. A spontaneous formation of gaps in the iris is also sometimes observed when occlusio pu- pillse makes its appearance in early childhood. The iris is then fixed not only at its ciliary, but also at its pupillary margin, being attached to the mem- brane that exists in the pupil. As the eye grows, the iris is stretched con- stantly more and more between its two points of attachment until atrophy and finally dehiscence in spots occur. In this way, through the formation of an opening, the sight may be spontaneously restored. In like fashion, the for- mation of gaps (or even the separation of the iris from the ciliary margin) may take place in cases in which the iris was attached to a cicatrix of the cornea in childhood. The dilated vessels that are frequently visible in the atrophic iris, have quite often a course that does not in any way correspond with the regular radial arrangement of the normal vessels of the iris. As a matter of fact, vessels of this sort, as anatomical examination shows, do not lie in the iris itself, but in a thin exudative membrane deposited upon it. The protrusion of the iris does not take place uniformly, but with the forma- tion of projecting prominences separated by constrictions. The latter repre- sent the more resistant, radial fibers which do not give way before the pressure of the aqueous until afterward. The condition in which the iris is found pro- truding in a greater part of its circumference, while one sector of it remains in its normal situation, is generally referable to the fact that at this spot an adhe- sion of the surface of the iris to the lens exists, preventing its protrusion. It would, therefore, be a mistake to select just this spot for performing an iridectomy, although on other accounts it would seem to be very suitable for such a purpose, because of the greater depth of the chamber there. If the iris has been pushed forward as far as the cornea, it may become agglutinated to the latter in places, and in this way anterior synecbise may be produced without there having ever been a perforation of the cornea (see page 308). DISEASES OP THE IRIS AND OP THE CILIARY BODY. 307 It should be remembered that seclusio and occlusio pupillse develop not only as the result of irido-cyclitis but also in connection with the larger perforating ulcers of the cornea if the margin of the pupil is incarcerated through its whole extent in the cicatrix. In this case, too, the usual consequences of seclusio pupillae make their appearance ; the iris is pressed forward as far as the cornea, and an increase in tension takes place, as is so often observed in staphyloma of the cornea (see page 315, and Figs. 60 to 63). The cornea in irido-cyclitis suffers harm through the deeply situated infil- trates that may form in it (see page 196), through the deposition of exudate (deposits, hypopyon), or through the contact of the iris, which when lasting a long time produces corneal opacity (page 196). In the stage of atrophy of the eyeball a zonular opacity frequently forms upon the cornea. Keratitis bullosa and vesiculosa also often make their appearance iii eyes which are blinded by irido-cyclitis. The anatomical changes, after an irido-cyclitis has run its course, manifest themselves under microscopical examination as follows: The atrophic iris is thinner than usual (Pigs. 93 and 93), and consists chiefly of fibrillary connective tissue. The cells of the stroma with their slender branches have been trans- formed in great part into coarse, round cells filled with pigment (k, Fig. 90) ; masses of pigment also are often found lying free in the tissue. The vessels are in part obliterated and the nerve trunks also have disappeared. The sphinc- ter pupillffi and the retinal pigments are the parts which remain the longest. The ciliary body, including both the ciliary muscle and the ciliary processes (Pig. 97, c), is also found to be atrophic in old cases. The two innermost layers of the ciliary processes, however, often undergo proliferation, the two strata of cells of the pars ciliaris retinas growing extensively into the cyclitic exudates (/) ^ig- 98). By the traction which the masses of exudate, as they shrink, exert upon the ciliary processes, the latter are greatly elongated, so that their apices project well toward their posterior pole of the lens ; when the traction is still greater, the entire ciliary body is pulled out of its bed (c, Pig. 98). This trac- tion upon the ciliary body is one of the causes of the continuous or constantly recurring sense of pain, which exists in so many cases of old irido-cyclitis and sets the patients almost frantic. The exudates themselves consist in the recent state of round cells and of an interstitial substance of fibrin, in varying proportions (Pigs. 91 and 95). The exudates afterward become organized into false membranes, the round cells turning into spindle cells and ultimately into connective-tissue fibers. In this way a very tough tissue is produced, which grates when cut through, and which rightly bears the name of "hull." On account of this tenacity it puts great difficulties in the way of any attempts at the forma- tion of a pupil. In cases in which the irido-cyclitis has been produced by a foreign body, the latter not infrequently is found imbedded in this hull of exudate. Besides the above-mentioned tissue constituents there are often found in the exudation membranes new-formed blood-vessels which have developed from the neighboring organs, the iris and ciliary body, and also pigment which takes its origin from the retinal pigment layer of the iris and of the ciliary body. The lens which is inclosed in the exudation membranes forms with these a rigid diaphragm separating the anterior from the posterior section of the eyeball. The lens becomes opaque and disintegrates, its capsule ruptures, and masses of exu- 308 DISEASES OF THE EYE. date penetrate into the capsular sac. If these masses afterward become ossified, the picture — to be sure only an apparent one — of ossification of the lens may be developed. By the subsequent shrinking of the exudation membranes, softening and diminution in size of the eyeball — atrophy of the eyeball — are produced. The anterior chamber becomes shallower, because the hull of exudate which is stretched between the ciliary processes and arches over the posterior surface of the lens («, Fig. 98) tends, as it shortens, to become approximated to a straight line (c, Fig. 100), and in so doing presses the lens forward. In other cases, on the contrary, the cicatricial traction may manifest itself more in a backward direction, so that the anterior chamber becomes deeper. Through the same force of traction cicatrices in the cornea or in the sclera, with which the exu- dates are connected, are drawn steadily inward {N, Fig. 100) ; hence the de- pression of cicatrices after injuries or operations is always to be considered a bad omen for the course of the disease. The traction of the exudates further- more causes detachment of the retina (r. Fig. 100) and often, too, detachment of the ciliary processes and even of the chorioid {cli). The cavity of the vitre- ous is reduced to a small space {g) lying directly behind the lens. The space beneath the retina (s) and also beneath the chorioid, wherever detached (a), is filled with an albuminous transudation and often also contains extravasated blood. In advanced atrophy, the sclera (S) is thrown into folds and is thick- ened in spots. The hull of exudate not infrequently becomes ossified later on, and, if the chorioid has participated in the process of exudation, the whole back part of the eye may be occupied by a shell of bone. The optic nerve is atro- phied to a thin strand of connective tissue. 69. Etiology of Iritis and Cyclitis.— Iritis and cyclitis are either primary or secondary in tlieir development. In the first case, the original site of the disease is in the iris or ciliary body itself ; in the second case, there is an affection of neighboring parts, which has been transmitted to the iris and the ciliary body (e. g., in iritis with ulcer of the cornea). Primary inflammation of the iris and ciliary body as well as of the uvea in general is caused in the majority of cases by a deep-seated general disease, such as syphilis, scrofula, etc. In these cases both eyes are frequently affected, although not always at the same time. Furthermore, many of those cases which at present we still re- gard as purely local inflammations and which, because their origin is unknown to us, we designate as idiopathic, certainly belong in the same category. In proportion as our knowledge of the interdependence of morbid phenomena increases, the group of so-called idiopathic in- flammations of the uvea will melt away. Among the primary iritides the only ones of undoubtedly local nature are traumatic and sympa- thetic iritis. We may, therefore, classify the inflammations of the iris and the ciliary body with reference to their etiology according to the sub- joined scheme. In it, as well as in the subsequent description, the expression " iritis " stands for the sake of brevity as the representa- tive of iritis, cyclitis, irido-cyclitis, and irido-chorioditis— that is, for DISEASES OF THE IRIS AND OF THE CILIARY BODY. 809 all inflammations which predominantly affect the anterior part of the uvea : A. Primary iritis. Iritis in con- sequence of general dis- " eases. Iritis as a local affec- tion. B. Secondary iritis. 1. Iritis syphilitica. 2. Iritis scrofulosa. 3. Iritis tuberculosa. 4. Iritis rheumatica. 5. Iritis gonorrhoica. 6. Iritis in acute infectious diseases. 7. Iritis diabetica. 8. Iritis idiopathica. 9. Iritis traumatica. 10. Iritis sympathica. A. Primary Iritis.— 1. Syphilitic Iritis.— Syphilis is by far the most frequent cause of iritis, at least half of all the cases of iritis being ref- erable to it. For the most part, it is acquired syphilis that we have to do with. The diagnosis of syphilitic iritis is very easy in those cases in which the characteristic formation of nodules (iritis papulosa) is present. The nodules have a yellowish-red color, are of the size of a pin's head or larger, and are situated either on the ciliary or the pupil- lary margin of the iris, but never between the two zones in the mid- breadth of the iris. The nodules afterward disappear again by resorp- tion without any purulent disintegration taking place. At the places where they were situated, broad and solid synechia are left, and there is often also a circumscribed atrophy of the tissue of the iris. At other times no distinct nodules are found, these being so small that they lie concealed within the tissue of the iris, but several portions of the pupillary margin are greatly swollen, or at all events there are un- usually broad synechias which do not yield to atropine {b, Fig. 94). Finally, in many cases iritis syphilitica presents absolutely no charac- teristic marks ; the diagnosis, then, can be certainly established only by demonstrating the presence of syphilis, or the favorable action of antisyphilitic remedies. Syphilitic iritis generally belongs to the secondary stage of svphilis. It makes its appearance soon after the first eruptions upon the skin (macular or papular), for which reason we may compare the nodules in the iris to papules or to condylomata, and may designate the iritis as iritis papulosa. In most cases, the time when the iritis iirst appears is comprised within the first year after the infection has taken place. JMore rarely the iritis breaks out in the later stages of syphilis, and is tlien not associated with the formation of nodules. In exceptional cases, however, nodules do show themselves in this late form also and they must then be regarded as gummata (iritis gummosa). These are observed both in the iris and the ciliary body. They may attain great 310 DISEASES OP THE EYE. dimensions, break through the envelopes of the eyeball, and bring about the destruction of the eye. Iritis also occurs in consequence of hereditary syphilis, although by no means as frequently as after acquired syphilis. Parenchymatous keratitis, dependent upon hereditary syphilis, is often associated with iritis. Sometimes it happens that the iritis becomes, comparatively speaking, very conspicuous, while the keratitis attains but a slight de- gree of prominence ; and there may even be iritis without any keratitis whatever. Iritis due to hereditary syphilis is a disease of childhood and youth, while iritis resulting from acquired syphilis is usually observed only in adults. Syphilitic iritis is very frequently associated with diseases of the posterior section of the eye — that is, with inflammation of the chorioid, retina, and optie nerve. Moreover, it displays a great tendency to recur. 3. Iritis Scrofulosa. — This bears in its appearance and course much resemblance to iritis due to hereditary syphilis. It is often marked by the presence of large, lardaceous-looking deposits or by lardaceous exu- dation masses, which appear to grow out from the sinus of the cham- ber. It is found in the ages of childhood and youth in scrofulous per- sons, and also in those suffering simply from anaemia. 3. Iritis Tuberculosa. — See § 74, Tumors of the Iris. 4. Iritis Rheumatica. — This occurs in persons who have been ill with articular rheumatism (arthritis rheumatica). It is the form of iritis which has the greatest tendency to recur. From the fact that in many cases the recurrences of the iritis coincide with recurrences of the rheumatism (attacks of swelling in the individual joints), the con- nection between the two is demonstrated. Iritis also occurs as a result of arthritis deformans and arthritis urica [gout]. 5. Iritis Gonorrhoica develops in those cases in which gonorrhoea has given rise to a general infection. This latter runs a course similar to that of acute articular rheumatism, but generally of a milder char- acter. As a general thing the knee-joint is the part first attacked by inflammation, which may afterward migrate to the other Joints also ; associated cardiac complications may even occur. This disease is known as gonorrhoeal gout [rheumatism]. Iritis does not generally set in until after the, outbreak of the arthritis, but there are cases in which gonorrhoea causes iritis alone and no disease of the joints. Just as the gonorrhoeal lesion of the joints is very similar to articular rheu- matism, so also gonorrhoeal iritis resembles in external features the rheumatic variety. Like the latter, too, it very frequently exhibits re- currences, with which is frequently associated a renewal of the discharge from the urethra or a return of swelling in the affected joints. 6. Iritis in Acute Infectious Diseases. — Among these relapsing fever is the chief one in which iritis forms a frequent complica- DISEASES OP THE IRIS AND OF THE CILIARY BODY. SU tion. It is usually protracted in its course, but ultimately goes on to a cure. 7. Iritis Diabetica. — This is often associated with copious exudation into the anterior chamber (hypopyon), but on the whole runs a favor- able course (Leber). 70. 8. Iritis Idiopatliica. — Under this head are comprised those cases in which the inflammation apparently develops spontaneously in the iris, without its being possible to make out the presence of any local cause (traumatism, etc.), or of a constitutional affection. In many cases a cold is charged with being the cause of the iritis, but in most instances the cause remains obscure. Acute idiopathic iritis is generally unilateral ; it attacks none but adults, and those, in most cases, of the male sex. The iris of the adult man is much more prone to be inflamed than is the iris of the child. In childhood, therefore, iritis is rare anyway, and if no local cause (trau- matism, sympathetic ophthalmia, transmission from the neighboring parts) is present, the existence of a constitutional afllection can always be demonstrated. Chronic idiopathic iritis generally appears under the form of irido- cliorioiditis chronica (also called iritis serosa). This disease is associ- ated with but very slight symptoms of inflammation ; injection of the eyes and pain are present only now and then, and with but little inten- sity when they do exist ; frequently the only complaint that the patients make at all is in regard to the steadily increasing disturbance of vision. Examination of the eye shows posterior synechise which slowly increase in numbers until finally seclusion of the pupil is developed. Almost always too there is a thin membrane present in the pupil. The iris be- comes atrophic early, and afterward, when seclusion of the pupil de- velops, bulges forward in hump-shaped projections. Hypopyon is never present, but instead there are very frequently fine deposits which point to the implication of the posterior division of the uvea, an implication which also manifests itself through the presence of opacities in the vitre- ous. As these opacities continually increase in number and the vitreous at the same time becomes liquefied, the latter is finally converted into an opaque, mucilaginous liquid. Subsequently opacity of the lens is added, and atrophy of the chorioid and retina sets in. The interfer- ence with vision in these eyes is, therefore, always much greater than the optical obstructions in the anterior division of the eye (deposits, membrane in the pupil) would lead one to expect. This disease, which really affects all parts of the eyeball, in most cases terminates in com- plete blindness. In consequence of the seclusio pupills, increase of tension sets in with blindness from excavation of the optic nerve ; after- ward the eyeball may become ectatic. In other cases, blindness takes place under the guise of a gradually developing atrophy of the eyeball ; the eye becomes softer, and the retina undergoes total detachment. 312 DISEASES OF THE BYE. Chronic irido-chorioiditis almost always attacks both eyes. It runs so slow a course that years pass before complete, blindness makes its appearance. It is a disease of advanced age, and is one of the most frequent causes of incurable blindness in elderly people, especially fe- males. The cause of it appears in many cases to be seated in bad nu- tritive conditions, or in early cessation of the menses ; but very often cases occur in patients who, apart from their eye trouble, are perfectly healthy. 9. Iritis Traumatica. — The causes of this are traumatisms of all kinds, especially if perforation of the eyeball has taken place, and par- ticularly if a foreign body is left in the eye. Operations upon the eye- ball are, of course, to be counted among the traumatisms, and of these the most dangerous with regard to iritis and irido-cyclitis are the cata- ract operations. The irido-cyclitis that follows traumatism is frequently of the most serious nature, so that atrophy of the eyeball speedily ensues ; in con- tradistinction to iritis due to constitutional causes, which even when the inflammation is a violent one often gets well without leaving any ill results worth mentioning. With traumatic iritis and irido-cyclitis in the wider sense of an in- flammation produced by direct injury to the iris, may be also enumer- ated the following cases : Iritis frequently develops when, after open- ing the lens capsule, the masses of lens matter as they swell come into direct contact with the iris and 'press against it. The same is the case when there is pressure made upon the iris by a lens which is obliquely placed or completely dislocated. Finally, there might also be adduced in this connection those cases in which an intra-ocular tumor or cysticercus in a certain stage of development sets up a violent irido- cyclitis. The exciting cause of traumatic iritis in cases of the sort just adduced may be of three kinds : either mechanical injury (traction, contusion), chemical irritation (e. g., in the case of contact with swollen portions of the lens or in the case of a cysticercus) ; or, finally, infec- tion from without. The last-named cause is without doubt the most frequent. 10. Irido- Gyclitis Sympathica. — When inflammation is carried from an eye suffering with irido-cyclitis over to the other side and attacks the other eye, which has hitherto been sound, the disease produced in the latter is designated by the name of sympathetic inflammation. This inflammation, like the primary one, makes its appearance under the guise of an irido-cyclitis. In the majority of cases iritis sympathica is preceded by a prodro- mal stage. The patient notices that during the performance of fine work he is suddenly obliged to stop because the work grows indistinct before his eyes ; after a period of rest he is again able to continue his DISEASES OP THE IRIS AND OF THE CILIAEY BODY. 313 work. This interference with vision is caused by a weakness of the accommodation. Another symptom of the prodromal stage is sensitive- ness to light, and also, though not often, violent pain, the latter appear- ing sometimes at a portion of the eye which is symmetrically placed with reference to the diseased portion of the other eye. These symp- toms are also denoted by the name sympathetic irritation. They may, in rare cases, exist for years without inflammation supervening. In most cases, however, after a short time (from a few days to a few weeks) they pass over into manifest inflammation. Sympathetic inflammation declares itself by a development of the objective symptoms of irido-cyclitis together with an increase of the subjective troubles just described. Ciliary injection, contraction of the pupil, discoloration of the iris, and the formation of synechise are found. Deposits are almost never wanting, while, on the other hand, hypopyon is not ordinarily present. Minute opacities show themselves in the vitreous. These changes sometimes set in insidiously, sometimes sud- denly with great photophobia and considerable pain. In the severest cases the very first attack of inflammation induces annular or total pos- terior synechia and occlusion of the pupil ; in less severe cases it is possible, with suitable treatment, to effect after many weeks the disap- pearance of the inflammation, although a number of synechias are left behind. Unfortunately, after an interval during which the cure is ap- parently complete, a recurrence of the inflammation almost invariably sets in. By reason of this and subsequent recurrences the eye at length is destroyed, either as the result of increase of tension (due to seclusio pupillffi) or of a slowly developing atrophy. Those cases are to be classed as the exceptions which run so favorable a course that the patient gets off with a single attack of inflammation, and retains an eye with serviceable sight. The affection of the first eye, which gives rise to a sympathetic in- flammation, is always an irido-cyclitis, and is, in fact, almost without exception, an irido-cyclitis traumatica, due to a penetrating injury of the eyeball. All cases of traumatic irido-cyclitis are not equally fraught with peril for the second eye. To be regarded as particularly danger- ous are : (1) Those cases in which the injury has affected the region of the ciliary body, and particularly if it has left the iris or the ciliary body incarcerated in the cicatrix. For this reason, unsuccessful cases of Graefe's cataract operation have become a frequent cause of sympa- thetic inflammation. (3) Cases in which a foreign body has been left in the eye. The point of time at which the greatest danger of the transmission of the inflammation exists is when the irido-cyclitis in the injured eye is at its height. Hence sympathetic inflammation makes its appear- ance, in most cases, from four to eight weeks after the injury to the first eye has taken place. Later than this, when the traumatic irido- 314 DISEASES OF THE EYE. cyclitis has subsided and the eye has fallen a prey to atrophy, there need be generally no fear of sympathetic inflammation so long as the atrophic eye is free from inflammation and is not painful, either spon- taneously or to the touch. The danger for the other eye does not de- velop again until the atrophic eye becomes once more the seat of in- flammation and of pain — an event which, to be sure, very frequently occurs. The most usual cause for these recurring attacks of inflam- mation is the persistent presence of a foreign body in the eye or the continual shrinking and ultimate ossification of the exudates. In this way an eye which has been carried for many years in an atrophic state without causing trouble may suddenly become the cause of a sympa- thetic inflammation. While, therefore, the minimum period for the development of sympathetic irido-cyclitis is a few weeks (the shortest period hitherto observed is ten days), no limits can be set to the maximum period ; sympathetic inflammation has been seen to appear forty years and more after the injury of the first eye. An eye which has been destroyed in consequence of injury is therefore a constant source of danger to the other eye. It is not necessary for the injured eye to be perfectly blind for it to excite sympathetic inflammation. Cases occur in which the eye has retained a remnant of visual power after the injury and the irido- cyclitis following it, and has yet given rise to sympathetic inflammation. In that case it may happen that the sympathetically affected eye un- dergoes complete destruction, while the injured eye is still used to see with. It is important to know — especially with reference to prognosis and treatment — under what conditions sympathetic inflammation of the second eye occurs only as a rare exception, and hence is generally not to be apprehended. These conditions are : 1. Phthisis cornese, due to suppuration of the cornea (after ulcus serpens, acute blennorrhcea, etc.). 3. Staphyloma of the cornea. 3. Glaucoma absolutum. 4. Phthisis bulbi after panophthalmitis. In what way does the transfer of the inflammation from one eye to the other take place ? This question has not, up to this time, been definitely decided. Mackenzie was the first to direct the attention of physicians to the dependence of the inflammation of the second eye upon that of the first. His idea of the method of transmission was that the inflammation made its way backward along the optic nerve and passed over along the chiasm to the optic nerve of the other side, in which it traveled forward. This explanation was afterward given up, because the inflammation in the second eye made its appearance, not under the guise of an optic neuritis, but under that of an irido- cyclitis. Then, as the uvea is supplied by the ciliary nerves, the path of transmission was regarded as being in them. The ciliary nerves of the two sides are not connected with each other directly, as is the case DISEASES OF THE IRIS AND OF THE CILIARY BODY. 315 with the optic nerves through the chiasm ; hence the transmission of inflammation in this case can not be conceived of as a direct one. On the contrary, we should have to assume that the ciliary nerves starting from the inflamed eye cause an irritation in the nerve center, which is transmitted like a reflex to the ciliary nerves of the other side and to their termination in the eye. Eecently many (Leber, Deutschmann, and others) have returned to the old theory of transmission through the optic nerves. It is supposed that, through the injury of one eye, micro-organisms are introduced into it and multiply there. Then they are supposed to travel along the optic nerve and its sheaths from one eye across to the other and to excite inflammation in the latter. B. Secondary Iritis and Irido-cyclitis are the varieties which develop through transfer of inflammation from neighboring organs to the iris and ciliary body. Inflammations of the cornea are the lesions that most frequently give rise to it; above all the suppurative keratides, which are very frequently indeed complicated with iritis. Of the va- rieties of scleritis, it is the deep form that leads to inflammation of the iris and the ciliary body. More rarely, inflammations pass forward from the posterior section of the eye to the iris. Among conditions that produce this result are chorioiditis and detachment of the retina. The iritides thus produced are usually of a lighter sort or are chronic, insidious forms. Finally, we may also put down under the head of sec- ondary iritis the cases of iritis traumatica, already adduced, in which the iris is not ailected by direct traumatism, as the iritis due to swell- ing of the lens, to luxation of the lens, to intra-ocular tumors, to cysti- cercus, etc. That form of iyphilitic iritis which is associated with the formation of nodules is generally designated under the name of iritis gummosa. For it was believed that these nodular exudates were necessarily to be regarded as gummy tumors on account of their sharply circumscribed form, which gives them some- times just the appearance of small neoplasms. If we agreed to this view we should have to ascribe this form of syphilitic iritis to the tertiary stage of syphilis, which is specially characterized by circumscribed exudates (gummata) resembling new formations. But in so doing we should be contradicting clini- cal observation, which shows that iritis with the formation of nodules always occurs simultaneously with the symptoms of the secondary stage. We are hence justified in comparing the nodules in the iris with the papules and condylomata, which also belong to this stage, and in designating the iritis as iritis papulosa or condylomatosa (Widder). Another argument against the gummy nature of the nodules in the iris is the fact that they never break down nor suppurate, as gummata are apt to do. True gummata of the iris do exist, however, but they are extremely rare. Apart from its physical signs, the diagnosis of syphilitic iritis will, of course, always have to be based upon the history of the case or upon the demonstration of the presence of syphilis in the patient. But should we call every iritis which has no characteristic marks syphilitic, simply because it occurs in a syphilitic person? 316 DISEASES OF THE EYE. In the majority of cases, to be sure, we should be right, since syphilis is, in fact, the most frequent cause of iritis; but still a syphilitic patient may also acquire an iritis from any other cause whatever. In the absence of other guides, the in- dication in every case is to initiate an antisyphilitic treatment. This will, in most cases, cause rapid improvement in iritis of syphilitic origin, while other kinds of cases are but little or not at all affected ; from which fact a conclusion may be drawn as to the source of the iritis. The effect of antisyphilitic treat- ment is also of assistance in making the diagnosis in those cases in which we are in doubt as to whether a nodule in the iris is of syphilitic nature or must be regarded as a new formation (sarcoma, tubercle). Syphilitic iritis also occurs during intra-uterine life; the children then come into the world with the remains of it, such as synechise, occlusion of the pupil, atrophy of the iris, and even atrophy of the eyeball. As regards the acute infectious diseases, we find that, if we except relapsing fever, they only exceptionally give rise to iritis. We are acquainted with cases of iritis following pneumonia, intermittent fever, typhus, iniiuenza, variola, ery- sipelas, and mumps. The iritis, moreover, that sometimes accompanies herpes zoster, should probably be put down under this head. Of the chronic diseases, I have seen general alopecia sometimes accompanied by a severe irido-cyclitis ; and by many chronic nephritis is adduced as a cause of iritis. Some few cases are known in which a transient iritis with hypopyon recurred regularly with the menses in women. Sympathetic Ophthalmia. — The symptoms of sympathetic irritation which generally precede the inflammation are regarded by many as something entirely different from the latter and having no connection with it. They are thought to be produced through the ciliary nerves, while the transmission of the inflam- mation takes place through the optic nerves. It is adduced as a proof of the essential difference between irritation and inflammation that the former is cer- tainly and permanently relieved by the enucleation of the eye originally af- fected, while this operation is powerless against sympathetic inflammation. On the other hand, it can not be denied that in very many cases the symptoms of inflammation develop so gradually and imperceptibly from the symptoms of sympathetic irritation that no sharp line of distinction can be drawn between the two, and the inflammation appears only in the light of an exacerbation of the prodromal irritation. It is supposed that the sympathetic disease may appear not only in the form of an irido-cyclitis, but also under some other guise. The greatest variety of affections have been described as sympathetic. Among non-inflammatory affec- tions, cases of paralysis of accommodation, of amblyopia, and of blepharospasm have been adduced as sympathetic ; among inflammatory affections in the pos- terior division of the eye, neuritis, chorioiditis, and glaucoma; and in the an- terior division of the eye, conjunctivitis and keratitis. Most of these accounts are to be received with great caution, because observers have often gone too far in taking the sympathetic nature of the disease for granted. The fact that an eye has been destroyed through traumatism by no means justifles us in regard- ing, without further proof, any subsequent disease of the other eye as sympa- thetic. This assumption should be made only when such disease presents the characteristic clinical picture of sympathetic irido-cyclitis, or when, upon the enucleation of the eye first diseased, the symptoms in the second eye recede too DISEASES OF THE IKIS AND OF THE CILIARY BODY. 31 7 rapidly to be accounted for upon any other assumption than that the afEection of the second eye was caused by that of the first. The converse of this inference does not hold good— that is, the fact that enucleation of the first eye does not influence the course of the disease in the second is no argument against the sym- pathetic nature of the lesion; indeed, it is a well-established fact that when sympathetic ophthalmia has once broken out, enucleation of the eye first dis- eased is not generally able to cause much change. Can an irido-cyclitis of non-traumatic origin be transmitted to the other eye? We very often see irido-cyclitis develop spontaneously first in one eye, then in the other. But we must not therefore at once conclude that the inflammation has been transmitted from one eye to tlie other. It may be that we have to do with a deeply seated common cause, generally of constitutional nature, which makes itself felt first upon one eye, then upon the other. Nevertheless, un- doubted cases of sympathetic inflammation have also been observed without any antecedent traumatism or perforation of the envelopes of the eyeball. In this category belong the instances of irido-cyclitis in the case of intra-ocular tumor and of cysticercus, in which the presence of a constitutional disorder as the common cause of the disease of the two eyes can be excluded. The fact de- serves mention that the wearing of an artificial eye over an atrophic stump may be the source of sympathetic inflammation through the irritation which it causes. In regard to the method of transmission of the inflammation, the view that it takes place by the way of the optic nerves is chiefly based upon the experi- ments of Deutschmann. In animals, it is not possible to excite by the injury of one eye a sympathetic inflammation in the other. Hence Deutschmann has em- ployed another method, namely, the injection of cultivations of fungi (especially of the staphylococcus) either into the eye itself or beneath the sheath of the optic nerve. He found that the fungi traveled from the site of injection along the optic nerves to the brain. At the base of the brain they made their way to the optic nerve of the other side, and passed down upon this to the eye. Here tbey set up an inflammation in the form of a neuritis of the intra-ocular end of the optic nerve, and with this, in one or two cases, an irido-cyclitis was as- sociated. The animals, moreover, speedily perished from general infection. Whether the inflnramation which Deutschmann produced in this way in the second eye is identical with sympathetic inflammation in man has not yet, to be sui'e, been certainly established. 71. Treatment of Iritis and Cyclitis.— In every case of iritis and cyelitis it is incumbent upon us, on the one hand, to combat the local symptoms {indicatio morii) ; on the other, to remove the causes lying at their foundation {indicatio causalis). In those cases in which an etiological factor is not demonstrable, we are thrown back solely upon the symptomatic treatment. 1. Symptomatic Treatment.— Airo^me is tlie most important rem- edy in iritis. Inasmuch as it contracts the iris, it necessarily dimin- ishes the amount of blood in its vessels, and hence directly counteracts the hyperaemia. By paralyzing the sphincter it fulfills a second indi- cation which requires every inflamed organ to be put at rest ; the con- stant to-and-fro movement of the pupil is completely arrested by atropine. The third action of atropine consists in its rupturing poste- 318 DISEASES OP THE EYE. rior synechise which already exist and in its counteracting the forma- tion of new ones, through the dilatation of the pupil that it causes. The amount of atropine administered must be carefully regulated according to the degree of the intensity of the iritis. During the period of increase of the inflammation it is usually difficult to obtain dilatation of the pupil, because a spasm of the sphincter exists. In this case we must instill atropine several times a day. If this does no good, we place a little granule of atropine in substance in the conjunc- tival sac (for the necessary precautions, see page 276) ; this is better than to instill the solution too frequently, by doing which irritation of the conjunctiva (atropine catarrh) is readily set up. By the simul- taneous employment of cocaine the action of atropine may be height- ened. When the inflammation is abating, atropine is simply instilled often enough to keep the pupil constantly dilated. In cases of irido-cyclitis in which the implication of the ciliary body is particularly prominent, and also in cases of pure cyclitis, atropine is not always well borne. For, in proportion as the iris becomes nar- rower and its vessels can contain less blood, the vessels of the ciliary body are overdistended, since they have to take up the blood which finds no lodgment in the iris. Hence, in such cases, we must be very cautious in the use of atropine, and must suspend it whenever we find that the pain increases after the instillation. So also, when an irido- cyclitis is combined with elevation of tension, the atropine must be stopped and, if necessary, replaced by a miotic. In violent inflammation, moist warm compresses or poultices afford the best results, especially for the relief of pain. Cold compresses are generally not well borne, and are suitable only for recent cases of trau- matic iritis. Extensive bloodletting by means of six to ten leeches applied to the temple, or by a Heurteloup's artificial leech, may very greatly diminish the inflammatory symptoms in the bad cases ; not infrequently directly after such a bloodletting the pupil for the first time yields to the action of atropine, while before this it had remained in a constant state of spasmodic contraction. If the disease lasts a long time, the bloodletting may, if needed, be repeated once or twice. The production of profuse diaphoresis often has a very marked effect (see page 382). OpBrative proced^ires are for the most part indicated more in the sequelse of iritis than in recent inflammation. Paracentesis is per- formed whenever increase of tension sets in. It may also be tried in cases of long-persisting inflammation which will not yield to other remedies. As the aqueous escapes, the deposits upon the cornea are often washed out with it, and their escape can be facilitated by rubbing the cornea ; but the removal of such deposits is not the proper aim of paracentesis. Iridectomy is performed, but not while inflammation DISEASES OP THE IRIS AND OP THE CILIARY BODY. 319 still exists, save in very exceptional cases, since if we perform it then we should have reason to fear that the newly made pupil would be closed up again owing to a continuance of the exudative process. Hence we undertake an iridectomy only when we are compelled to do so because of the development of an increase of tension, or as a last resort in order to put an end to the iritis when all other means have failed. Otherwise we wait until the inflammation has run its course, and then perform an iridectomy, either because a seelusio or occlusio pupillse has developed, or as a prophylactic in relapsing iritis to prevent further recurrences. And, in fact, in many cases, an end is put once and for all to recur- rences by this means ; in other cases, however, this successful result fails to occur. A proper regulation of the mode of life in iritis requires first of all protection from the light, not only on account of the photophobia that is generally present, but also because light excites the pupil to contrac- tion. For the latter reason the protection against light must be applied to both eyes, since with the contraction of the pupil of one eye that of the other also tends to contract. The patient is kejot in a moderately darkened room, or is made to wear dark goggles. This is better than a bandage, which it would be difficult to apply to both eyes. The patient should be moderate in eating and drinking, and should abstain from spirituous beverages. Care should also be taken to secure bodily rest by the avoidance of all physical exertion and in severe cases by rest in bed. The healthy eye should not be strained by reading, etc. More- over, it is important to see that the bowels move easily. 2. Causal Indication.' — "With reference to the etiological factor, syphilitic iritis gives the most favorable prognosis, since it generally yields promptly to an energetic antisyphilitic treatment. The chief requisite here is promptness of action, since we are dealing with a lesion in which a few days may produce great and lasting damage (by the formation of a seelusio or occlusio pupillse). Hence mercury is selected, and this is best applied in the form of inunction (two to four grammes of blue ointment being rubbed in daily). The inunctions should be kept up until the diseased eye has become perfectly free from discolor- ation and then potassium iodide (up to three grammes a day) may be used for after-treatment. In iritis due to hereditary syphilis less value is attributed to specific antisyphilitic treatment and more to the strengthening of the organism as a whole. In iritis rheumatica sodium salicylate is administered, although not always with success. This drug also does good service sometimes in other forms of iritis, especially in iritis gonorrhoica and iritis dia- betica. In the former variety I have also employed with advantage the oil of gaultheria (fifteen drops per diem in capsules). In iritis traumatica the causal factor is first of all to be eliminated, in case it still continues to act. Foreign bodies are to be removed 320 DISEASES OP THE EYE. from the iris ; portions of the iris that are much contused or are in- carcerated are to be excised. A swelling or luxated lens causing iritis must be removed from the eye. To combat the inflammation of the iris, iced compresses are employed in very recent cases in addition to the atropine. With respect to those traumatic iritides which follow an operation, the most important part belongs to prophylaxis. This con- sists in strict antisepsis during the operation ; and, as a matter of fact, since this has been employed such iritides have become much more rare. Irido-cyclitis sympatJiica, too, is very amenable to prophylaxis, while, when it has once broken out, it often resists treatment of every kind. {a) The only certain prophylactic treatment of sympathetic inflam- mation consists in enucleation of the eye which might give rise to it. This is the case in every eye which has been made blind by injury and is painful either spontaneously or upon pressure. Most emphati- cally requiring enucleation are eyes which are suspected to contain a foreign body. A contra-indication to enucleation is present only when the injured eye has still a serviceable residue of visual power or can get it through an operation. When this is not the case, enucleation should, under the circumstances above given, be performed without de- lay. At the utmost, if the patient can not bring himself to consent to enucleation, it is permissible to wait until the prodromal symptoms of sympathetic disease make their appearance, since even in this stage enucleation is generally still able to prevent the outbreak of sympa- thetic inflammation. (5) When sympathetic ophthalmia has already broken out, the efEect of enucleation is uncertain. In the lighter cases it appears to exert a favorable influence upon the course of the sympathetic inflammation ; in severe cases, on the contrary, it is often of no use and appears some- times actually to increase the inflammation in the second eye. Hence we wait for an abatement of the inflammatory symptoms in the second eye before performing enucleation. The sympathetic inflammation itself is to be treated according to general rules. Of especial importance is the protection of the diseased eye from light, which is most perfectly attained by long-continued bandaging of the eye. Operations generally give a bad result, since they start up the inflammation again, so that the newly formed pupil is once m.ore closed by fresh exudate. Hence operations are done only when it is absolutely requisite (e. g., when done on account of increase of tension) ; other operations, such as, for example, an iridectomy for optical purposes, are put off as long as possible, preferably for years. 72. Treatment of the Sequelae of Iritis and Irido-cyclitis.— /so?fli!«i posterior synechim can often be ruptured by the employment of atro- pine either by itself or in combination with cocaine. Here it is not so much a long- continued action as a very energetic one that is required, DISEASES OF THE lEIS AND OF THE CILIARY BODY. 321 and this is most certainly secured by placing atropine in substance in the conjunctival sac. Still more effectual sometimes is the alternate use of miotics and mydriatics, the pupil being first contracted with eserine, then suddenly and energetically dilated with atropine. But since the iris is made hyperasmic by eserine, attempts of this sort must not be made until some time has elapsed since the occurrence of the iritis. It is frequently possible to rupture synechise which are narrow and drawn out into a point, while broad synechise (such as occur after syph- ilitic or sympathetic iritis) withstand all attempts. Annular posterior synedda (seclusio pupillag) demands iridectomy unconditionally, the object being to restore the communication between the anterior and posterior chambers. The operation is often difficult on account of the shallowness of the anterior chamber (due to protru- sion of the iris), and also on account of the atrophy of the iris. Accord- ingly, we must often be contented if we succeed in making a small opening in the iris. Then the anterior chamber, in consequence of the restoration of the connection between the two chambers, regains its normal depth, so that a second iridectomy can be performed later under more favorable conditions. Total posterior synechia also requires iridectomy, which, however, is often void of result, as on account of the adhesion between the sur- faces of the iris and the lens it is frequently impossible to excise a suf- ficiently large piece of the iris, or because the pigment layer of the iris, which has grown fast to the lens, remains attached to it. In such cases the only thing to be done is to remove the lens, too, even if it is still transparent (Wenzel's extraction, see remarks to § 162). If the lens is atrophied or absent, iridotomy is indicated (see § 157). Too much caution can not be inculcated in regard to the senseless way in ■which atropine is often used, as it still is, unfortunately, by many general prac- titioners, who instill ati'opine in every kind of eye disease. In many cases — e. g., in conjunctival catarrh — atropine is not only superfluous, but also causes the patient annoyance through the disturbance of vision produced by its use ; and in eyes which have a tendency to glaucoma, atropine may actually inflict great injury by determining an attack of acute glaucoma. Accordingly, atro- pine should be employed only upon quite specific indications, and should be applied no oftener than is requisite to obtain just the result desired. Even in iritis atropine is useless if the pupillary margin- is adherent to the capsule throughout, and the iris hence can not retract. If, after an iritis, one or two posterior synechias are left which do not rupture when atropine is energetically employed, we abstain from further treatment of them, since they generally do no harm to the eye. At the present time we have entirely desisted from releasing them by operation (corelysis). When, however, an annular synechia is present, we ought not to let it stay, but must make an iridedomy. This is also indicated in those cases in which the seclusion of the pupil is not yet indeed complete, but is on the verge of being so, only one small 21 322 DISEASES OF THE BYE. spot of the pupillary margin being free from it. For if we are dealing with a chronic irido-cyclitis, we can count upon this small spot soon becoming adher- ent too, and in that case it is better not to wait for the seclusion of the pupil to become complete. It is particularly advisable not to do so if the patient lives far from the physician, and might perhaps let the proper moment for the iridectomy pass by. In seclusio pupillas the iridectomy is made upward. If occlusio pupillse is simultaneously present, we should, according to the rules laid down for an op- tical iridectomy in § 155, make the coloboma to the inner side and below. But even in these cases it is advisable to make the iridectomy upward, because it is so often the case that the lens afterward becomes opaque, and in that case a coloboma situated above will be of advantage in performing the extraction that will be required later. In cases of chronic irido-chorioiditis, iridectomy is not only mechanically efficient by removing the seclusio pupillse, but it also has a favorable influence upon the entire nutritive condition of the eye. The vitreous clears up and the sight improves, often for quite a long time. If an operation is done upon eyes which have already begun to grow softer— that is, are on the road to atrophy — the eye in favorable cases fills out again, and the ocular tension becomes normal. Although enucleation generally afiords a sure safeguard against sympathetic inflammation of the other eye, nevertheless a series of cases is known in which, in spite of enucleation, inflammation has subsequently made its appearance. In every instance it has set in within a short time — from a few days to a few weeks — after the enucleation.* It must probably, therefore, be assumed that at the time of the enucleation the transfer of the inflammation had already begun. Yet even in this case enucleation does not fail to exert a favorable effect, since in the great majority of these cases the sympathetic inflammation runs an un- usually favorable course, probably because the removal of the first eye prevents the constant emission from it of new impulses for the production of inflam- mation. II. Injuries of the Iris. 73. In addition to what has been already said in the previous, sec- tions in regard to injuries of the iris and their consequences, the follow- ing special varieties of injury, which are most frequently observed after contusions of the eye, may be mentioned : 1. Under the name of iridodialysis f is designated the separation of the iris from the ciliary body. We then find on one side, at the ciliary margin of the iris, a black crescent which is formed by the sepa- ration of the iris from its insertion at this spot, so that we can look into the interior of the eye (Fig. 101). When the separation is pretty considerable, the edge of the lens (/), the ciliary processes (p), and the fibers of the zonula of Zinn stretching between the two can be recog- nized by means of lateral illumination in the gap that is thus produced. The pupil has lost its round form, owing to the fact that the pupillary margin toward the side of the iridodialysis has shortened so as to oc- * The longest interval so far observed has been thirty-two days (Snellen), f From Ipis, iris, and 5i