LECTURES ON THE ANATOMY, PHYSIOLOGY, AND DISEASES OF THE EYE.

the eye lays it open, not only to aceidell tal injury, but to various external LECTURES influences, while its position, and the source of its vascular supply, make it ON THE participate in the determinations of blood ANATOMY, PHYSIOLOGY, AND DISEASES to the head. OF THE EYE. Again, the eye is a part of the external surface of the body, connected with BY MR. LAWRENCE. the integuments through the medium of London Ophthalmic Infirmary, Moorfields. the conjunctiva, and hence participating in the various diseases which affect the skin ; not only in the acute diseases, such LECTURE V. as small pox, scarlet fever, and measles, Of Inflammation ; of the Classification of but also in the more chronic affections. As the component parts of the eye are Ophthalmic Diseases ; of Inflammation so numerous and so diversitied in strucaffecting the whole globe of the Eye. ture, as all these are subject to the same Gentlemen, diseases and consequent changes which THE eye and its appendages are highly are incident to analogous structures in organized parts, very delicate and vas- other parts; and as this delicate and comcular, and copiously supplied with nerves. plex organisation is exposed to numerous They exhibit also, within a very small and powerful causes of disturbance, we compass, a great variety of textures. We can understand how it happens that there find, in the visuat apparatus, specimens are so many distinguishable forms of ophof each of the three divisions of mem- thalmic disease. If each of these should branes, the mucous, the fibrous, and the be designated by a particular name, the serous; the conjunctiva, the sclerotica, catalogue will be a very long one. I shall with the cornea, and the surfaces con- rather consider these forms as various taining the aqueous humour, correspond- modifications and results of one and the ing respectively to each of those classes. same affection. namelv. inflammation.a book, enIt contains also nervous, muscular, and Dr. Rowley has glandular parts ; and, besides these, seve- titled, " A Description of 118 of the ral tissues of peculiar structure, to which principal Diseases of the Eye," and perthere is nothing analogous in other parts haps it might be possible to collect a still of the body, as the iris, the ciliary body, larger catalogue. We should, however, the ehoroid coat, and the transparent approach nearer to the truth, if we were media. Each of the latter has its own to admit only of one disease-of inflanacharacteristic structure ; the cornea, the mation. crystalline lens, the capsule of the lens, Thequestion then will occur, what is and the vitreous humour, resemble each inflammation ? There ought to be no difother only in being transparent. ficulty in giving an answer. We are conBy the nature of its organisation, by tinually talking of inflammation ; almost its office and its situation, the visual ap. constantly occupied in observing and ,paratas is exposed to numerous external treating what we call inflammations. The anfll1ences and internal sources of disease. existence of this morbid affection is daily The aid of this sense is wanted on every more and more generally recognised as occasion ; hence the organ is incessantly the source of disease, and it seems likely, exercised during our waking hours. It is ultimately, to spread itself over the whole excessively exerted by a numerous class field of nosology. The attention of phyof society, especially those who are en- sicians and surgeons has been very much gaged in the mechanical occupations re- turned towards it; it has been carefully quiring close attention. The situation of investigated, and numerous books have [Dec. 3, 1825.] [No. 118.

published

338 been written upon it, but it has not yet ther been clearly or sufficiently explained. If you should ask a surgeon, or look into a book for an explanation, you would learn that inflammation consists in an assemblage of four alterations in a part, namely, swelling, redness, heat, and pain. The word inflammation, which is popular, denotes the most striking character of external inflammations, viz. the increased heat of the part. The other items in the nosological description are drawn from the same source, and by no means derived from a general survey of fhe process as it occurs in all structures. The description is not applicable to the eye; some of ita textures may be inflamed without exhibiting all these changes. In some inflammations of the cornea, of the iris, and of the crystalline capsule, there is no visible swelling-no redness, nor can we trace the existence of heat or pain. If we admit, however, that inflammation is generally characterised by the assemblage of these four circumstances, still they are only to be regarded as its symptoms-as the external signs of that alteration in the part which constitutes the inflammatory condition. We want to know what internal change causes these four external signs. This, I believe, is not yet known. We know. something of particular inflammations, as of the celluJar membrane, muscle, or skin, because we can observe their progress and ex. amine the parts affected ; but when we at-tempt to explain the nature of inflam-

of a third how others urine or semen some secrete of the and so on. As we know dif. these causes which

membrane;

muscle,

blood,

nothing

striking produce is not surprising that the

it intimate nature of the process called inflammation should still be a mystery to us. Those who have investigated the subject experimentally, have arrived at such different conclusions in the results which they pretend to draw from actual observation of the living process, that we cannot place much reliance on such in. quiries. Some see in inflammation, an increased flow of blood to the part ; others think they observe obstruction and diminished afflux. That there is increased activity of the capillaries has been gene. rally believed, yet an elaborate attempt has been made to show that these parts are in a-state of debility, and that they do not exert themselves as much as in I, the natural condition. These circum. stances are sufficient to show that the. real nature of inflammation is still unknown. It is not always one and the same pro. cess; if it were, pathology and treatment would be very simple. The phenomena which it exhibits vary very considerably. In the first place the character of the inflammatory disturbance may be more or less strongly marked. and its progress more or less rapid. 7 is distinction is denoted by the terms acute or violent, and chronic, languid, or indolent inflammation. These words indicate a difference of more or less, or in the duration mation generally, we are investigating an or stage of the inflammation. It is a abstract term. Inflammation, in this difference in degree, and not in kind; point of view, is a creation of the mind ; in fact, you may have every gradation of it does not convey any sensible ideas; the affection, from that in which you its acceptation cannot be defined or limi- barely recognise theexistence of increased ted by reterence to nature, our only safe action, np to the violent unnatural exergnide. Perhaps the most general idea tion in which all the ordinary functions which we can form of inflammation, is are perverted or suspended, and even the that of increased activity in the capillary very structure changed or destroyed. circulation of a part, whether evidenced These diversities are only generally by increased size of vessels and redness, pointed out by the terms acute and or by deposition of new matter and con- chronic ; the shades of difference between sequent visible changes, sorh as thicken- these two extremes are endless. Some ing or opacity. But this general notion persons are of opinion that there is a is not worth much; the inflammatory difference not only in degree, but in kind chronic inflammation. process is rot merely increased activity, between acute there is an alteration in the nature and They, admit preternatural excitement, and consequently increased exertion, as result of the exertion. The agents of inflammation then, are the foundation of acute inflammation ; the capillary vessels, which carry on the but they suppose chronic inflammation active business of the animal economy, to be the result of an opposite condition, performing the various processes of nu- that is of debility. Thus we -read and trition, growth, secretion, and excretion. hear of active and passive, sthenic and We do not yet know the differences of, asthenic inflammation. For my own part, arrangement or action which lead to the I consider the phrase " passive inflamvarious results of vascular exertion ; we mation" to be a contradiction in terms; tell how it is that the capillaries and if inflammation be an increased acticannot of one part deposit bone, those of ano- vity of the capillary vessels, any theory

ferences,

and

339 erro- sphere, and of the weather; all those It is true that inflammation may causes which produce endemic and epioccur in weak as well as in strong and demic diseases. healthy states of body ; and the pheno- A most important source of difference mtna of the local disturbance, as well as in the character of inflammation, is difthe effects it produces on the system, ference of structure in the part affected ;’; will differ very materially in the two in- in this respect, each structure has a sort stances. The essential nature, however, of characteristic inflammation peculiar to seems to be the same in both cases; for, itself. The inflammation of a membrane, if we look to inflammation occurring even for instance, differs very much from that in the weakest states of the system, we of a muscle ; and both differ from that still find the local changes and results of the skin. which under other circumstances we refer A consideration of the numerous diswithout hesitation to increased activity. tinct component structures of the eye, of This may be observed even in the last the several circumstances which may mostage of typhus fever, when the patient is dify the inflammatory process in those reduced to the lowest state of debility. structures, and of the varied results to The terms active and passive, sthenic which it may tend, will enable you to acnnd asthenic inflammation, therefore, count for the long catalogue of ophthalappear to me to convey either no clear mic nosology. If the enumeration of so meaning, or one which is founded on ar many diseases should tend to alarm you, erroneous view of the subiect. The same and induce you to suppose that there is observation is still applicable something extremely intricate and comto the terms arterial and venous inflam- plicated in the subject, you may re-assure mation ; for how can we tell whether the yourselves, by reflecting that these vaarteries or the veins are exc:usively rious affections may, for the most part, affected ? Is the distinction even prac- be referred to a common origin, and particable ? If we trace the vessels of a part, take of a common nature; and that as we soon come to the point at which we they are all the offspring of inflammation, can no longer distinguish between arte- so the treatment of them is, in essential ries and veins ; we find a minute net. circumstances, similar. In fact, the more work of vascular ramifications, which attentively we observe the phenomena of cannot be unravelled or distinguished. disease, and consider the effects of remeThatthe state of the constitution dies, the more we are led to adopt unishould modify inflammation, is a circum- formity and simplicity of treatment, and When the less confidence are we inclined to stance Mhich might be expected. it occursin a healthy individual, it is place in complicated plans, or great dicalled common inflammation ; the terms versity of remedial means. true, proper, simple, idiopathic inflamarrangement of the diseases of the mation, are used in the same sense. If eye adopted by Beer in his large work, the patient be young, strong, and of a full is a simple one. He treats, in the first habit, the inflammation will be acute, ac- place, of inflammation, and then of tive, or phlegmonous, in its character. the consequences of inflammation. HowThe terms sympathetic, specific, spurious, ever, we cannot refer all the affections of mixed, are applied to thoe modifications the eye to one or the other of these of inflammation which appear in various heads; ’and indeed Beer is obliged to states of constitution, more or less differ- adopt a third division, a sort of catalogue ing from the healthy condition. A pecu- of undefined affections, which do not liar character will be given to the inflam- come under either of the preceding divimatory process by certain differences of sions. As we do not know the exact naorganization, or natural defects of consti- ture of the inflammatory process, as the tution, such as the scrofulous ; by cer- pathology of some parts of the eye is yet tain acqnired or morbid condition::, as in in an imperfect state, and as we have selgont or rheumatism, and by certain states dom an opportunity of examining the reof constitution, resulting from morbid sults of ophthalmic diseases after death, poison, such as in syphiiis. Under these we are unable to present a classification various conditions, the appearances of or arrangement of those diseases founded inflammation will differ very much from on clear and unequivocal principles, and those which it exhibits’in persons of good in all respects satisfactory. If it were natural conrtitutioxi,- and in sound health. required to give an arrangement of all Inflammation is also modified by many diseases and defects of the eye, that other circumstances which influence the is, of all those matters upon which our body more or less powerfitlly; such as professional opinion may be required, I MX, age, temperament, habits of diet, should be inclined to adopt a greater and others ; season, states of the atmo- number of divisions than Beer hae’done

which refers it to debility must be

neous.

more justly

The

--

340

The inflammations would occnpy the first itself. 1n the tatter case itis divided into division, aud they might be conveniently idiopathic or common, and sympathetic arranged, according to their seat, into or specific. I prefer, however, the ar. those of the orbit, globe, and lids ; those rangement according to its seat; it is of the globe beingsubdivided into the internal and external. This head would of itself embrace a long catalogue of diseases. Secondly, I should speak of the consequences and concomitants of inflammation, as they appear in the individual parts of the apparatus; thirdly, of tumours in the lids, in the globe, and in the orbit; fourthly, of malignant affections of the globe, such as scirrhus, cancer,

hæmatodes, melanosis;

and least liable to mistake.

con.

considering inflammation of the

eye,

the most

troversy In

simple, or

you should bear in mind that it is usnally limited in its origin, and that it becomes more general in its progress. It generally commences in one structure, is confined at first to that structure, and does not extend beyond it, if judiciously treated. But if it is not attended to in the ontset,

fnngns fifthly, of affections riot referrible to inflamma- if suitable means are not adopted to check it very readily extends be. tion ; and the sixth head might comprise its progress, original seat of disease, and congenital peculiarities or defects. Under yond theultimately embraces the whole these six heads, we might conveniently perhaps of the Mr. in his Essays organ. Wardrop, enough arrange every thing which can be the subject of professional consideration on the Morbid Anatomy of the Eye, takes up each particntar structure, and gives respecting the eye. an account of the changes which may be Inflammation of the eye has hitherto, observed in it. This course of proceed. and especially in this country, been treatis very proper in a work illustrating ing ed of in too general a point of view ; it the morbid anatomy of the organ, but it has been described and spoken of too is not so applicable to our present purmuch under the single head of ophtlialpose of considering the nature and treatmia. The late Mr. Ware, in his Treatise ment the diseases to which it is suboa " The Ophthalmy," as he calls it, inwith this view, instead ofinsulating ject; cludes all inflammations of the eye under the affections and changes incidental to this head, and the same arrangement, if each it is better to turn our attenit can be so termed, has been followed tion tissue, to those aggregates of phenomena, by Scarpa. The word ophthalmia is a which most commonly appear in pracvery general and comprehensive one ; tice. Neither do I mean to adhere to the to its it according etymological import, which I have previously would embrace all inflammations of the arrangement it most convenient to mentioned, finding organ ; now it is evidently impossible to begin by describing the strongly marked one the characreduce into description inflammations of the eye, and particnters of the various inflammations affectthe external, because the consideralarly ing the several structures of the eye. Many tion of these will show the effects which of these have but few points of resem- inflammation is capable of producing in blance. What similarity of character can the and will give ute the oppororgan, we trace between inflammation of the tunity of laying down the general princonjunctiva, cornea, iris, retina? In- ciples by which its treatment should be flammation of the external tunics differs But though I do not adopt the regulated. from that of the internal. Hence order which I have widely .I,suggested as convethe all to these affecembrace attempt nient in a nosological catalogue of ophtions under one general head of descrip- thalmic diseases, I propose to speak of tion, instead of elucidating the subject, all the particulars comprised under those can only lead to obscurity and confusion. six heads in the present course of LecThe general descriptions of ophthalmia tures. are usually applicable only to external inflammation of the eye, while the other I shall first speak of inflammation forms of the affection are entirely ne. affecting the whole eye-ball ; of common glected. The whole globe of the eye may inflammation seated both in the external be at once inflamed, but this is not a very and internal structures. This affection, In general you will which is by no means of common occurcommon occurrence. find inflammation of the globe to be either rence, is called by Beer Ophthalmitis idioexternal or internal, and very commonly pathica. Some very serious exciting only one of the external or internal tunics cause is required to produce this affectioli, and it occurs chiefly in robust individuals is the seat of infl mation at a time. Ophthalmic nflammation might be of fnll habit. When this general inflamclassed either according to the structure in mation of the globe is fully developed, it which it is seated, or according to our is characterised by very considerable ideas of the nature of the inflammation paiu, increased external redness, more

of

341

or less external swelling of the part, by is merely increased lachrymal discharge, and by tion.

a

form of external inflammm-

The aecees of light is. very offensive to redness and swelling of the upper lid. The pain is always a very lead- the patient in general inflammation of the ing symptom, and one to which the pa- globe of the eye ; the pupil contracts to tient immediately adverts, and which exclude it, and the patpebrae are spasmoattracts the attention of the practitioner. dically closed. The motious of the eye It is exceedingly severe, and is described and lids are put a stop to, the whole exsometimes as acute, sometimes as of a ternal surface becomes exquisitely sensidull aching kind, and sometimes as con- ble, and as the slightest attempt to exert veying a sense of throbbing and burning. the organ occasions great pain, the paVery commonly the patient mentions tient keeps it as completely as possible that he 1’ecis the eye particularly tight, at rest. The surface of the organ, at the as if it were too large for the orbit, and commencement of the affection, is rather about to burst from it. The pain is by stiff and dry, but this dryness goes off, no means confined to the anterior part ofand is succeeded by a copious lachrymal the organ, but is deep-seated and extends discharge, which is increased if the eye to the surrounding parts, as the brow, is exposed to the light or any external cheek, temple, and back of the head. irritation. The eyelids, particularly the The redness is inconsiderable at the com- upper, are red, especially at their ciliary mencement ; but it gradually increases, edges, aud more or less swoln. and ultimately the surface of the eye Such are the circumstances which chaassumes a bright red colonr like that ofracterise inflammation of the whole globe scarlet cloth. The vessels of the scle- in its first stage; as it proceeds to the rotica first become the seat of congestion, second period, we begin to see various and the redness observable in an earlv alterations of structure. The irjs bestage of the disease is seated in the comes changed in colour, loses its brilsclerotic coat. The conjunctiva soon liancy, and no longer exhibits the usual participates in the vascular congestion, motions on varying the quantity of light and the distension of its vessels produces to which it is exposed. The pupil conthe bright scarlet redness, which conceals tracts, and loses its clear blackcoloiw. the fainter pink tint of the sclerotica. The nature of these changes will be bestThe conjunctiva then begins to swell, ter understood afterwards, when I come and a deposition takes place not only into to the subject of internal inflammation. the texture of the membrane, but into the The cornea loses its transparency, beloose cellular tissne, which unites it to comes more or less opaque, and vision is the sclerotica. Hence the conjunctiva lost. The alteration in the cornea, and is elevated on the surface of the sciero- in the state of the pupil, would account tica, above the level of the cornea, the for imperfection or loss of sight, but the edge of which it often overlaps so as to latter often occurs while the cornea is hide a considerable portion of it from sufficiently clear for the transmission of view. This bright scarlet elevated ridge light, and the, pupil is still open, in conse. of conjunctiva, projecting beyond, and quence of the violent inflammatory dissurrounding the cornea, firm, of consi- turbance and consequent change of struederable breadth and acutely sensible, is ’, ture in the retina. The patient still sees, technically called chemosis. In the affec- or fancies he sees, luminous sparks and tion which I am now describing, it may flashes of fire before his eyes, when there is no light in the chamber, or during the be termed true inflammatory chemosis. The deposition of lymph from the ves- night, in consequence of the disturbed sels of the inflamed conjunctiva into the state of the retinal circulation. subjacent cellular tissue, occasioning this As the inflammation continues, the globe swelling, is similar to that which takes swells, and the sense of its being too place in external inflammation, of acute large for the bony cavity in which it is character. The tumid state of the con- contained is not very erroneous. We junctiva is not owing to the effusion of cannot say positively that all the internal blood into the cellular texture, as Scarpa tunics of the eye are in a state of intiornvery unaccountably supposes, when he mation, because we cannot see them ; confounds the inflammatory symptom but, when we find that the globe is actalled chemosis with ecchymosis. He has, tually increased in size, that the iris ia upon this erroneous supposition, proposed changed in structure, and that the retina the making of incisions through the tu- has lost its sensibility, there is little reamefaction to allow the escape of effused son to doubt that the internal pal ts of the blood. You will find in some treatises a eye generally are inflamed. From the distinct chapter upon chemosis, as if it combined internal and external swelling, were a particular disease of the eye ; it the globe of the eye is actnally mechani-

I

342

cally fixed in the anterior aperture of the consequence of effusion into the opening orbit, and rendered motionless. The tu- during the inflammatory stage, and the mid palpebræ are protruded ; ectropium subsequent organisation of the effused of the lower lid takes place, and a por- matter. In this case vision is generally tion of the anterior surface of the eye either completely or in a great degree projects externally in a denuded state, lost, but tae form of the eye remains.

The most favourable termination that can be expected is the recovery of the organ, with the cornea clear and the pupil open ; still, in this case, the retina has generally suffered so much as to produce greater or less imperfection of vi. sion. The affection which I have now de. scribed may be considered as common, true or proper inflammation, seated in the whole structure of the eyeball ; for the circumstances which I have enuinerated sufficiently prove that all the component parts are inflamed. As I have not yet described any other affection, it would be premature to speak much of the distinction between this and other iuflammations. I shall only observe, therefore, that the present inflammation M characterized by its commencing at one and the same time in the external and internal tunics of the eye. Internal inflammation may spread to the external coats, or external inflammation may extend inwards: but, iu this affection, both constitution, proceed to a great height. sets of parts are inflamed at the same Under such an aggravation of the local time. It is characterized by the uni. and general symptoms, the pain changes formity and correspondence, in degree, in character, it becomes throbbing; ri- between the various symptoms ; viz. the gors are felt, and suppuration of the redness, the pain, the increased lachryglobe takes place; the cornea turns oftrial discharge, and the tumefaction, by the a dull white and then yellow, and the regularity of its course, beginning in a globe is ultimately converted into an moderate degree, gradually increasing abscess. The occurrence of suppuration and proceeding without any interruption doe! not produce the relief usually ex. or remission to its full development, and perienced from that change, in conse. by the severity of the constitutional disquence of the firm, unyielding nature of turbance which accompanies it. the sclerotica and cornea ; the pain, toPrognosis.-If the affection be seen gether with the sense of bursting and early, and actively treated, you may exthrobbing, continues for some days, until pect to arrest it, and to prevent change the cornea bursts externally and gives an of structure in the organ, and consequent exit to the matter contained in the inte. injury or loss of sight. But, if you find rior of the eye. The patient then expe- the inflammation fully developed, even in riences relief; matter is discharged for a comparatively early stage, you will a time; the tunics of the eye collapse hardly succeed in controlling it, so as to into a small space, shrink into the orbit, preserve the powers of the organ unimand the original form of the organ is paired. When the chemosis is actually completely lost. The vitreous and crys- established, when the cornea has become talline humour of the eye generally es- clouded, when the colour of the iris is cape when the bursting of the globe first changed, and the pupil contracted, you gives an exit to the confined matter. may be very certam that the patient will Such is the termination of this affection lose his sight. The principal points for in its worst form ; when it does not pro- vour consideration are the degree of the ceed so far, and when its progress has internal inflammation, and the effect been checked by treatment, the cornea I which it may have had in changing the becomes opaque, and remains so; the structure of the internal tunics. ’ The of the iris and pupil, and the pupil is either closed, or very much con- condition tracted, and the aperture iillcd by a state of the retina, are the criteria by the which your opinion must be regulated. adventitious like a piece of red flesh. The mucous membrane of the lids becomes the seat of inflammation equally violent with that in the conjunctiva of the globe; effusion takes place into the cellular texture of the lid generally ; the external integument becomes red, as well as the mucous lining, and the consequent swelling forms a large convex protuberance on the upper lid. In a local disease of such violence, affecting a very vascular and sensible organ, situated in the immediate vicinity of the sensorium, marked constitutional sympathy may be expected, and accordingly we find inflammatory fever of a decided character from the commencement of the affection. There is a quick, hard, and full pulse; flushed face, an pain of the head; a dry and hot skin a white and rather dry state of the long e, deficiency of appetite, resttessness, and generally want of sleep at night. If the disorder is not checked, the local pain, and the feverish state of the

newly-formed

substance,