Iris Ciliary Body Choroid | Operating Microscopes

Anatomy. The second envelope surrounding the media of the eye is formed by the choroid, lining the sclerotic and continued in the ciliary body and iris. Indeed, embryologically and histologically considered, these three portions of the eye should be viewed as forming a single membrane, which has been called the uvea or uveal tract.

The choroid is situated between the sclerotic and retina, clearly separated from the latter membrane by an elastic layer. The choroid is united to the sclerotic only very loosely, except in the neighborhood of the optic nerve, where the two membranes are very firmly joined (as will be described shortly). The choroid is composed of the following four layers :

(a) The outermost layer, which unites the choroid to the sclerotic (suprachoroidea), is composed of coarsely meshed cellular tissue, mixed with elastic fibres, lymph corpuscles, oval nuclei which belong to the endothelium, and a great number of pigment cells, sometimes round, sometimes furnished with multiple prolongations, which allastomose with each other. Tile whole are united together by a very fine homogeneous and perfectly structureless intercellular substance. This external layer of the choroid, the lamina fusca of the older authors, contains the vessels and nerves which supply the iris.

(b) The second layer is that containing the large vessels of the choroid (vascular layer). The veins are situated to the outer side, the arteries to the inner, and they lie in a tissue analogous to that which forms the subjacent layer. The adventitious tunic of the vessels is very strong, and contains, according to H. Muller, involuntary muscular fibres. The pigment cells in this situation are less numerous, smaller, furnished with very short prolongations, and mixed with other non pigmented cells. Beneath this layer is found

(c) The layer of the capillaries, united into a very close network, forms what is called the chorio capillaris (membrana Ruyschiana). The capillaries are embedded in a homogeneous, structureless tissue.

(d) The fourth layer, intimately connected with the chorio capillaris, is formed by the elastic layer, a very fine film resembling the membrane of Descemet, but much thinner, and, like all the vitreous membranes, homogeneous, and without structure. It is provided, on its internal aspect, which touches the retina, with an epithelial layer composed of flattened cells very rich in pigment (tapetum). This pigment varies in intensity, but is especially present in the neighborhood of the macula lutea, and, generally speaking, is abundant in newly born children. The epithelial layer serves as a basis for the rods of the retina, and in reality belongs to that membrane, as has been shown by embryological investigations.

There have also been found in the choroid, especially towards its posterior part, involuntary muscular fibres and a great quantity of nerve elements, fibres with a double contour and ganglionic cells. (MUller, Schweigger).

Towards the posterior pole of the eye, the choroid terminates in a slender and narrow ring, cellular and elastic, which surrounds the optic nerve. As we have already said, the membrane is in this situation very firmly united to the sclerotic, and supplies a few fine and isolated fibres to the neurilemma of the optic nerve, and to the lamina cribrosa.

In front, the choroid properly so called terminates at a point which has received the name of ora serrata, because the retina, ending at this situation, forms zigzags denticulated. It is at this line that the vascular tunic of the eye becomes the ciliary body.
The ciliary body is situated behind the anterior portion of the sclerotic, and is composed of two parts; the one external, the ciliary muscle; the other internal, the ciliary processes. The latter, seventy or seventy two in number, are generally parallel with the direction of the meridian, and are formed by folds of' the choroid. They arise near to the ora serrata, and increase rapidly in height, extending to ,the neighborhood of the equator of the lens, which they do not seem to touch. Having reached this situation, they abruptly curve towards the insertion of the iris, leaving a deep groove between them and the insertion of this membrane. The tissue of the ciliary processes is analogous to that of the choroid ; it is composed of cellular tissue, which encloses a few masses of pigment and a great number of vessels.

The chorio capillaris no longer exists in these organs ; the elastic lamina is here changed into a paler tissue, less persistent and more difficult to detach from the subjacent layer, and presenting on its internal surface prominences and furrows, from which it has received the name of reticulum. Pigmentary epithelial cells are also found on the surface of the ciliary processes ; there they are of irregular shape and very dark.

The external portion of the ciliary body which directly touches the sclerotic is formed by the ciliary muscle (tensor muscle of the choroid). Its unstriated fibres arise from the internal wall of the canal of Schlemm, by an insertion rendered more solid by some fibres which come from the membrane of Descemet (ligamentum pectinaturn) and from the sclerotic. In this situation t he fibres form a tendinous ring, which is strengthened by a layer of cellulo elastic tissue. The muscular fibres follow different directions ; the most external are parallel with the sclerotic, and become lost in the choroid ; those of the innermost layer are circular; the intermediate fibres are directed towards the ciliary processes ; so that the muscle, when viewed as a whole, is in the form of a triangle, of which the base is towards the ciliary processes, and the apex towards the canal of Schlemm. These smooth fibres form small bundles, which are separated from each other by cellular tissue, vessels and nerves.
The anterior portion of the uveal tract is formed by the iris. Its origin is at the junction of the sclerotic with the cornea ; it arises from the internal wall of the canal of Schlemm, along with the ciliary muscle. From thence, this membran ' e is directed inwards, and is spread over the convexity of the lens.

It presents a ring of variable size, the opening in which is called the pupil. Its greatest thickness is very near the pupillary margin, although the margin itself is thin. We can distinguish, on its anterior surface, a somewhat irregular circular line concentric with the border of the pupil, and at about a millimetre from it. In this line originate other lines and bands, which are circular near the margin of the pupil, but radiating near the ciliary attachment. The position of the line corresponds to the small arterial circle of the iris.

The color of' the iris depends on the quantity of pigment enclosed in its tissue. When it contains little or no pigment, the iris appears by interference to be blue; whilst a dark shade of iris is caused by a great quantity of pigment being enclosed in the tissue proper. This is composed of cellular tissue, forming undulating fascicull, which sometimes take a radiating direction, sometimes a circular. It encloses cells which may or may not contain pigment, and surrounds the very numerous vessels with which the iris is supplied.

The muscles of the iris are situated near its posterior surface. We distinguish near the margin of the pupil circular fibres concentric with the margin. These constitute the sphincter of the pupil. The dilator of the pupil is represented by a thin layer of straight and radiating fibres, which seem to arise near the ciliary ring, and are directed towards the sphincter, where, curving on themselves, they become lost in the circular fibres. The existence of a dilator muscle in the iris has been denied by several histologists.

The anterior surface of the iris is formed by a very thin endothelium, which covers a layer of anastomosing cells and lymphatics (Michel). Near to its ciliary insertion, we can distinguish elastic fibres which come from the ligamentum pectinatum of Descemet's membrane. The posterior surface is formed by a hyaloid elastic membrane, and is covered with a thick layer of pigment enclosed in round cells and of an amorphous intercellular substance. It is the continuation of the pigmented epithelial layer of the choroid which we have seen to pass over the ciliary processes, and which, likewise, covers the iris to the pupillary margin, in the neighborhood of which it increases in thickness, and beyond which it sometimes extends, so that we then see the pupil to be bounded by a very dark border.

Circulation of the Choroid, Ciliary Body and Iris. The following details of the circulation of the choroid and iris and ciliary body are those enunciated by Leber, whose researches have thrown new light on many points.

The structures which have just been described (choroid, ciliary body and iris) receive their arterial blood from the ciliary arteries, which are classed as posterior ciliary arteries (direct branches from the ophthalmic artery), and anterior ciliary arteries (arising from the arteries of the recti muscles). The short posterior ciliary arteries, about twenty in number, perforate the sclerotic near the entrance of the optic nerve. They divide dichotomously in the choroid, and distribute themselves rapidly over it till in the neighborhood of the ora serrata.

Starting from their entrance into the choroid, they send branches to the capillary layer, in which, finally, all their ramifications are lost, with the exception of' a few branches which pass the ora serrata to anastomose with branches of the anterior ciliary arteri.es and with the long posterior ciliary arteries. The direct transformation of these arteries into veins does not exist. The anterior portions of the choroid, situated beyond the ora serrata, receive their arterial blood from the long posterior ciliary arteries, and from the anterior ciliary arteries. Those arteries (long posterior ciliary), having pierced the sclerotic very obliquely near the optic nerve, follow a course in the external layer of the choroid (membrana supra choroidea), until they reach th ciliary muscle, where they divide into two branches, which, diverging from each other, pierce the muscle, and, at its anterior border, assist in the formation of the great arterial circle of the iris.

The anterior ciliary arteries, five or six in number, reach the sclerotic by piercing 'the insertions of the recti muscles. On the sclerotic they are directed towards the margin of the cornea, and in their course send some branches into the interior of the eyeball. These branches perforate the sclerotic, and, in the ciliary muscle, unite arteries to form the great arterial circle of the iris, at the margin of the ciliary muscle, and a second arterial circle situated in the midst of the substance of the muscle itself. From these arterial circles arise: (i) Arteries for the supply of the anterior part of the choroid, recurrent branches which anastomose with the short posterior ciliary arteries, and finally form the capillary system ; (2) the arteries of the ciliary muscle these are in the form of a very fine capillary network, the meshes of which run parallel with the muscular fibres of this structure ; (3) the arteries of the ciliary processes these pierce the ciliary muscle before reaching the processes, and divide into a great number of ramifications, which form anastomoses, and terminate in the veins at the ftee margin of the processes, although, as yet, we are unable to decide whether they are transformed directly into veins or undergo the capillary transformation ; (4) the arteries of the iris, which are carried very near to the anterior surface of the membrane, radiating towards the pupillary margin.

In their course they anastomose frequently with each other, forming little loops, and sending some ramifications towards the posterior surface of the iris, which there form a large meshed capillary system. A few of the arteries which are directed towards the pupillary margin unite to form the small arterial circle of the iris ; others are directed as fine ramifications to the border itself, where, curving on themselves so as to form dilatations, they assume the character of veins. Previously, they furnish some small branches to the sphincter of the iris, where they form a very fine capillary network.

The venous blood from the iris, ciliary body and choroid, leaves the eye for the most part by the star shaped veins of the choroid (vasa vorticosa). The veins of the iris are united to those of the ciliary processes, with which, also, the veins of the ciliary muscle are in part blended, so as to form a serrated network on the internal surface of the ciliary processes, facing the choroid. It i's only when they reach the margin of that membrane that their veins dip so as to come to the external surface.

The veins of the ciliary processes and of the iris do not traverse the ciliary muscle ; whilst the arteries, as we have already seen, pierce it, Thus, contractions of on the arterial circulation, and, during accommodation, the, ciliary processes dirninish in size, but become swollen when' accommodation is at rest. After the veins of the iris and ciliary body have united in the choroid, they run from before backwards to the star shaped veins, by which all the venous blood of the choroid leaves the eyeball. These star shaped veins, situated near the equator of the eye, thus receive, in addition to the veins already mentioned, those of the anterior parts of the choroid, of which a certain number are united to the veins of the ciliary processes, and to those of the posterior part of the choroid. These last are situated between the short ciliary arteries, so that these vessels exercise a mutual pressure on each other, from which it may be presumed that they regulate the supply of blood in these parts. Thus, the stream of blood following the same direction from before backwards, in both the arteries and the veins, the distention of the arteries will accelerate, by consecutive compression, the circulation in the veins, whilst the distention of these latter will retard the current of blood in the arteries.

All the veins of the choroid thus converge from different points, and terminate in a branch which perforates the sclerotic. It is by this arrangement that the star shaped veins are formed; of these we generally find four or six, which anastomose by tolerably large branches.

A portion of the venous blood from the ciliary muscle leaves the eyeball by another route than that which we. have just described. A dozen or fourteen small veins perforate the sclerotic near the margin of the muscle, and, while dividing so as to anastomose, run towards the ciliary venous plexus (canal of Schlemm), with which a large proportion are incorporated, whilst a few join the anterior ciliary veins of the subconjunctival tissue. From the canal of Schlemm, several veins, having previously perforated the sclerotic, go towards the margin of the cornea ; others spread out in the venous episcleral network.

There are thus two ways by which the venous blood from the iris, ciliary body and choroid is brought to the surface; a posterior passage by the star shaped veins, which is much the larger, and an anterior passage, which has just been described. In the case of hyperxmia, or of intraocular pressure, such as to compromise the star shaped veins at the point where they pierce the sclerotic, the blood by preference takes the anterior passage, and we then see an increase in number and size of the anterior ciliary veins. The nerves of the choroid, ciliary body and iris come from the ophthalmic ganglion, and from the naso ciliary nerve. Arising from the ganglion, ten to twenty nerves (short ciliary nerves), having perforated the sclerotic near the optic nerve, enter the choroid; there they supply the nerve elements which we have already described, or run between choroid and sclerotic to the ciliary body.

The nerves coming from the naso ciliary (long ciliary nerves) perforate the sclerotic near the insertion of the superior oblique muscle. They go to the ciliary muscle, where they divide and anastomose with the short ciliary nerves. It is from this network that the nerves of the iris come, which follow almost the same course as the vessels; their mode of termination is not exactly known.

ART. I. Hyperemia of the Iris.

The first symptom which hyperemia of the iris produces is congestion of the episcleral tissue, the vessels of which are, as we have seen, closely connected with those of the iris. Hence, we find a more or less intense pericorneal injection. Another symptom consists in the impaired effect of atropine on the contraction of the pupil ; it dilates it, but with difficulty, and for a shorter time than in a normal eye. If we find this condition, we must make sure that it does not depend on an affection of the cornea preventing or retarding the action of the remedy, or on the presence of adhesions of the pupillary margin (posterior synechia).

The third symptom of hyperemia of the iris consists in a change in the coloration of this membrane, due to the circumstance that a yellowish red tint is added to its natural color. Thus a blue iris becomes slightly yellowish ; a brown iris takes on a rose tint. This discoloration is so much the more apparent in simple hyperemia of the iris, that the aqueous humor preserves its transparency, and that the tissue composing the membrane is not the seat of exudations as in iritis. In cases of very chronic hyperemia (for example, after the operation for solution of cataract), the change of coloration of the iris depends also on alterations of the pigmentary cells of the iris stroma, accompanied with atrophy of the pigment which forms the extreme margin of the pupil, the contour of which thus loses its regularity and appears dentated. Advancing years also produce an analogous alteration, and cause the iris to lose its usual brilliancy, without any symptom of inflammation.

Hyperernia of the iris passes off with the removal of the exciting cause, without leaving any trace; or it may lead to iritis, either spontaneous or secondary to an irritating course of treatment as, for example, the use of a nitrate of silver lotion. Etiology. Hyperaemia of the iris always precedes and accompanies inflammation of this membrane. It is also found in hyperemic or inflammatory affections of the structures in vascular connection with the iris. Thus hyperernia of the iris is formed as a consequence of excessive and prolonged efforts of vision, and in inflammations of the anterior parts of the choroid and ciliary body. It is also observed in ulcerative or traumatic affections of the cornea, and in inflammations of the conjunctiva, acute granulations, and phlyctenular ophthalmia, especially if these affections have been carelessly treated with irritants.

Our treatment ought to be directed to the cause of the hyperemia, as well as to the local congestion. We should recommended absolute rest for the eyes and the avoidance of everything which is likely to increase the congestion ; for example, a too brilliant light and general congestions to the head. We s should also recommend the prolonged use of atropine or duboisine, so as to give complete rest to the internal muscles of the eye.

ART. II. Iritis.

Inflammation of the iris adds to the symptoms of hyperernia already described that of the production of an exudation. This exudation may be formed:

At the margin of the pupil and on the posterior surface of the iris, where it is very apt to produce adhesions between the iris and the capsule of the lens (posterior synechia).
On the anterior surface of the iris, in the aqueous humor and on the membrane of Descemet. On the anterior surface of the iris, it assumes the form of a very thin fibrinous structure, which destroys the brilliancy of the membrane, giving to it the appearance of an unpolished surface; it also often extends to the pupillary field. In the aqueous humor, it produces either general haziness, or flocculi, or small floating membranes, which may gravitate to the bottom of the anterior chamber (hypopyon).

In the parenchyma of the iris itself, increasing the volume of the membrane or producing pupillary excrescences.

We shall have to distinguish several forms of iritis Simple or plastic iritis, serous iritis, parenchymatous iritis, and, as a special form of this last variety, syphilitic iritis.

A. SIMPLE OR PLASTIC IRITIS.

The pericorneal injection in this form is more or less pronounced according to the intensity of the inflammation. In severe cases, it is even accompanied with edema of the subconjunctival tissue, producing a chemosis, which to some extent masks the injection around the cornea.

The aqueous is somewhat muddy; the iris itself is more or less deficient in brilliancy and changed in color; and the pupil, generally contracted, is perfectly immobile, or excessively sluggish in its movements.

When the affection has already led to the formation of adhesions between the margin of the pupil and the lens, the outline of the pupil is irregular; or, if at first sight it seems normal its irregularities become apparent by focal illumination or by using atropine By this remedy the as yet feeble adhesions are often at once torn asunder, and the pupil then regains its circular form. In such cases we often see the debris of &se synechie and of the pigment of the iris on the capsule, where they indicate the position of the adhesions. Again, deposits of exudation, varying in their size and in their form, may exist in the pupillary field itself. In other cases, the synechie resist the action of atropine, which then only dilates those portions of the iris which are still non adherent, and this irregular dilatation may cause the pupil to assume the most varying forms.

These adhesions are sometimes limited, sometimes large, isolated and more or less numerous; or the margin of the pupil may adhere to the capsule throughout its entire extent. To this condition the term complete or annular synechia has been applied.

When at the same time the exudation completely fills the pupillary field, it produces occlusion or obliteration of the pupil.

B. SEROUS IRITIS.

Instead of the plastic exudation, which characterizes simple iritis, we observe here a hypersecretion of the aqueous humor, which is at the same time muddy, and which precipitates deposits of variable size and form on the posterior surface of the cornea and on the capsule of the lens. The pericorneal injection is often very slight, and the appearance of the iris is apparently changed by the haziness of the aqueous and of the cornea.

The anterior chamber is deeper, the intraocular pressure increases, and, in consequence of the disturbance of the nerves thus produced, the pupil is semi dilated, and remains nearly immobile. In slight cases, the haziness of the aqueous humor and Descemet's membrane is often so inconsiderable that it is discovered only on very careful examination. We then find a general cloudiness produced by the suspension of solid particles in the aqueous humor, or, in more pronounced cases, flakes which float in the humor, and gravitate to the bottom of the anterior chamber. This haziness disappears if we permit the deposit to escape by paracentesis. The posterior surface of the cornea presents a slight general opacity, intermingled with grayish points, varying from a very fine point to the size of a pin head, or even larger. The alterations of the membrane of Descemet, which, in addition to these deposits, may consist in modifications of its epithelial layer, are frequently accompanied with opacities of the vitreous (Irido choroiditis).

C. PARENCHYMATOUS IRITIS.

In this variety of iritis the iDflammation and exudation affect the elements of the tissue composing the membrane, which increases in thickness either throughout its entire extent or partially.

Thus we have a swelling and a hypergenesis of the cellular elements, in addition to which there is a disturbance of the circulation, followed by the appearance of tortuous vessels on the anterior surface of the membrane. This swelling is further increased by a plastic or purulent effusion in the parenchyma, at the margin or on the surface of the iris. These exudations unite the pupillary margin to the capsule, in the form of pigmented synechie, rendering the pupil immobile. The space which separates the posterior surface of the lens from the iris, as also the pupillary field, is filled with grayish or yellowish material ; effusion into the anterior chamber likewise takes place, and can give rise to an extensive hypopyon.

The aspect of the anterior surface of the iris varies according as the disease is general or more definitely localized. It always appears tarnished, discolored and swollen, with isolated pigment spots due to the hypergenesis of the cells of the stroma. But in the first case this appearance is general ; in the second it is seen near the free border or in the continuity of the membrane, either as deeply colored papilliform excrescences, or as small yellowish tubercles surrounded with vessels. These nodosities rise above the level of the iris, and are insensibly lost in its tissue. This condition of the iris is accompanied, especially in the primary stages of a severe case, with a well marked pericorneal injection, With conjunctival congestion and with chemosis. The lids even may participate in the irritation, especially the superior eyelid, which becomes red, shining and oedematous.

D. SYPHILITIC IRITIS.

Syphilitic iritis may present itself in the form of any of the varieties of iritis which we have just described. Nevertheless, there exists a form of partial parcnchymatous iritis, which is very often met apart frorn any specific manifestation, but yet so frequently in conjunction with constitutional syphilis, that it may be considered as characteristic of this diathesis.

In syphilitic iritis only a small portion of the membrane changes its color, becomes swollen and vascular, and takes on a red, yellowish or brownish tint. This small tumor, of variable dimensions, extends sometimes considerably beyond the level of the iris, and resembles in its structure a gummatou3 tumor in its early stage. Several may be observed at the same time. They rarely undergo a fatty or purulent degeneration ; in most cases they disappear as do the nodosities of parenchymatous iritis, generally by absorption, and' the tissue of the iritis atrophies at the affected spots. In this variety of partial iritis the pericorneal injection also appears most quickly towards the portion of the corneal margin which is nearest to the seat of the alteration. In the different forms of iritis which have just been described, the subjective sensations, such as pain, photophia, disturbance of vision, etc., are present with very variable intensity.

Pain is sometimes entirely absent ; it is, as a rule, more acute in parenchymatous and simple iritis than in the serous form, and probably arises from compression of the ciliary nerves by the hyperemic tissue or by the exudation. Thus in slight cases there is often only a sensation of heat and of heaviness in the eye ; in other cases the patients complain of lancinating pains in the suborbital region, in the forehead, and in the parts supplied by the contiguous branches of the fifth pair.

The pain, as a rule, increases towards the evening and during the night, so as entirely to deprive the patient of sleep. The lachryination and photophobia vary with the intensity of the ciliary pain, without ever being so pronounced as in keratitis. Disturbance of the vision depends essentially on the affection of the aqueous humor and on the effusions which are formed in the pupillary field. Therefore, when we find a greater diminution of the acuteness of vision than is accounted for by these alterations, or defects in the pupillary field, our attention should be directed to the complications which so frequently occur in certain forms of iritis (choroiditis and opacities of the vitreous body).

When the invasion of iritis is very acute, in a feeble or irritable subject, it may be accompanied by a general febrile reaction, by gastric disturbance, and even by vomiting.

Progress and Termination. When iritis follows an acute course, it soon attains its maximum intensity, and imperceptibly disappears at the end of three or four weeks. The pericorneal injection grows pale, the conjunctiva becomes white, the pupil is dilated, regaining its circular form, and the effect of atropine is increasingly strong. The exudations are absorbed, and the iris assumes its normal condition.

Traces of' synechie are sometimes seen to remain on the capsule of the lens, as small pigmentary spots, which even after the lapse of yea] indicate the existence of a previous iritis. Notwithstanding this corr. plete cure, there remains for a certain time a great liability to relaps( especially if the muscles of the iris have not been ke t at rest by th p prolonged use of atropine.

This favorable course of iritis may take from a few weeks to a fe months. Serous iritis, although more chronic, often passes off withot leaving any trace ; simple iritis much more frequently causes synechia which do not yield readily to treatment; parenchymatous iritis, if be developed in conjunction with or after a simple iritis, rarely admit of perfect repair of the affected tissue.

In a second series of cases the iritis is cured; but posterior synechi, have been formed, which are too strong to yield to the action of atrc pine. If they are not numerous and isolated, they may exist withou any serious consequences ; but these adhesions often exercise a mos baneful influence on the eye, because they produce incessant draggin of the membrane, during the movements to which the iris is constantl subjected by the action of light and of accommodation; they thu disturb the circulation and innervation. This danger is so muc the greater in proportion as the synechioe are large and numerous Indeed, they explain the frequency of relapses, which formerly wer by common consent ascribed exclusively to a general diathesis. I each of these new attacks, the disease becomes worse, because th synechioe already existing hinder the action of the atropine, and bc cause additional synechix are formed each time, thus rendering th communication between the anterior and posterior chambers of th eye more and more difficult, a communication which is essential to th equilibrium of the intraocular pressure and to the normal nutrition c the media of the eye. Again, when a complete posterior synechia i formed, with or without the obliteration of the pupil, this communica tion is entirely stopped ; the aqueous humor and liquids secrete behind the iris push that membrane forwards towards the cornea, and as it is retained at its pupillary margin by adhesion to the capsule, th peripheral portions of the membrane alone can yield to this pressure hence the iris assumes a funnel shaped appearance.

In these cases, the inflammation spreads to the ciliary processes an( to the choroid, the tension of the eye increases, and glaucomatou symptoms are produced (hardness of the eyeball, venous congestion anxsthesia of the cornea, characteristic retraction of the visual field) Later, the iris and choroid atrophy, the hyper secretion ceases, tile eye hall gradually softens, and at the same time a calcareous cataract i forined. We shall have to revert in greater detail to this complication to which the name irido choroiditis has been given and which often takes the inverse order, that is to say, beginning with an affection of the choroid, the disease extends to the iris.

In a certain number of cases iritis assumes an essentially chronic form ; here the inflammatory symptoms are greatly in abeyance, only the pupil is seen to be sluggish in its movements and sometimes slightly contracted; and, when examined by focal illumination, or after using atropine, isolated adhesions to the capsule are seen to exist. From time to time there is slight muddiness of the aqueous humor, and by small degrees the iris loses its bright reflection, becomes discolored and grows thinner, and the tissue gradually atrophies. Often, in the course of this chronic form, an acute exacerbation, with characteristic symptoms, supervenes.

Prognosis- The gravity of this disease depends on the cause of the Iritis, and on the alternations which it has already produced in the eye. If we get the disease in its early stage before the formation of synechiae, or if these still yield to the action of atropine, the prognosis is absolutely good; it becomes serious with the existence of numerous adhesions which resist the action of mydriatic. It is on this account that the chances of the cure are much greater in simple or serious iritiris. As compared with parenchymatous or suppurative. Again, the prognosis must take account of the various complications which may arise in the other membranes of the eyes; and, in traumatic iritis, of the simultaneous existence of other lesions.

Etiology.- Iritis may be observed as a consequence of any of the causes which produce a prolonged congestion of the scleral tissue- e.g.,the presense of foreign bodies for a long time in the conjuctival sac, or the imprudent and prolonged application of caustics. It may also be produced in consequence of persistent irritation of the iris itself, as by foreign bodies, by portion of the lens exercising pressure on it, by the dragging which results from anterior or posterior synechiae. Again, the infemation, after having its origin in the cornea, may be communicated on theiris, especially if the deep layer of this membrane are the seat of disease, or it may arise from inflammation of the anterior portions of the choroid. As a special cause there should be noted the sympathetic influence which an eye injured in the region of the ciliary body, exercises over its fellow. In this last case there may be developed an ophthalmia, so called sympathetic, which sometimes begins with the iris.

Idiopathic iritis occurs seldom in elderly people; it chiefly attacks children before the age of adolescence. It has been observed in consequence of menstrual irregularity, and chronic disease of the uterus and its appendages.

Amongst the diatheses which produce iritis, syphilis is the most important-almost three-fourths of the persons affected with iritis shows syphilistic symptoms-besides, iritic symptoms in early life have been attributed to congenital sypthilis. As to the rheumatic diathesis, it is true that iritis often results from exposure to cold, and is accompanied with rheumatic pains in other portions of the body; but it would be inaccurate to say that this variety has any special form. Undoubtedly, tubercles may appear in the iris before any other symptoms of general tuberculosis, but generally the effect of tuberculous and cancerous dyscraiae are only felt in the iris after they have attacked other organs. The same remarks hold true for metastatic or embolic iritis, observed in the courses of septicaemia, after puerperal fever, suppurating wounds, ect.

Treatment.- The first indication to be fulfilled in imflammation of the iris is to prevent the continual functional use of the muscles of this membrane, which contract incessantly under the influence of the light and of accommodation. Our objective is best attained by using atropine, or duboisine, which, in addition, by dilating the pupil, have the advantage of preventing the formation of posterior synechiae, and of assisting the intraocular circulation.

Mydriatics thus diminish the hyperaemia of the internal structures of the eye, and act favorably on the tention of the globe. We must use, in the early stages of iris, a concentrated ointment or solution( 2 or 4 grains to 3 I of water or Vaseline) as an instillation two three times a day, six drops in the course of half an hour( putting in one drop every five minutes). This method of using the remedy id preferable to installatins continued throughout the day, which, by the passing but often repeated irritation consequent on the application on the remedy, the deprive the eye of the necessary rest. In the majority of the cases, this remedy, if pure and carefully prepared, is very well borne by the eye; yet it sometimes causes considerable irritation of the conjunctiva ( see p.101). we must the substitute duboisine in similar doses, or, if this remedy be not better supported by the conjunctiva, cocaine, hyoscyamine, or a carefully filtered lotion consisting of –

Extract of belladonna . . . . . . . . . . . . gr.15
Distilled water . . . . . . . . . . . . . . . . . m 150

It is absolutely necessary to dilate the pupil, and it is only when this object has been attained that we may diminish the frequency of the instillations and employ a less concentrated solution, but still a sufficient strong one to maintain the dilatation.

Along with the mydriatics, we should recommend hot poultices kept on the eye for two hours at a time, and repeated four times a day. We may replace the poultices by hot lotions made with an infusion of chamomile, of belladonna, or of laurel water ( I : 15 distilled water).

The use of atropine and absolute rest for the eye, which must be protected from too strong a light and from cold, are indispensable, whatever may be the form of iritis with which we are dealing. At the same time, it is well to prohibit all heating food.

When we see that the inflammatory symptoms are very acute, and especially if we find pronounce ciliary pain which persists in spite of the employment of atropine, it is beneficiary to apply a few leeches to the temple in the evening ( the number varying according to the constitution of the patient and the intensity of the inflammation), to incise, if necessary, the chemosis, and to rub the forehead with mercurial and belladonna ointment.

In addition, it is necessary to procure sufficient rest for patients deprived of sleep, by subcutaneous injection of morphia, or by the administration of chloral.

In cases of serous iritis the use of atropine has seemed to determine, in the persons predisposed to glaucomatous attacks, an acute exacerbation of the disease; it must therefore, in such cases, be used with care. When the pain seems to depend on the hyper-secretion of the aqueous humor, otherwise implicated, and on the tension of the eye, great advantage may be delivered from paracentesis of the anterior chamber, which, if performed with the requisite precautions, may be repeated several times without danger to the cornea, and with great benefit as far as the disease is concerned. It is also in this variety of the disease, if it be prolonged, or if there have been relapses, that we must act on the bowels by repeated saline purgatives, and on the secretions of the kidneys and skin by the acetate of potash and by subcutaneous injection of pilocarpine, or hot sarsaparilla drinks taken in the morning while in bed, so as to cause a few hours’ diaphoresis. Again, we must, if the general health of the patient permit of it, establish counter-irritation by cuntaneous derivatives, such as vasicants to the neck, issues, and even seton. It must be forgotten that this affection, if accompanied by a serous choroiditis, may be assumed a glaucomatous character, and if we observe its distinctive symptoms (hardness of the eyeball, contraction of the visual field, venous congestion, anesthesia of the cornea), we are force to perform iridectomy.

The presence of a plastic exudation furnishes an indiction for mercurial preparations; if the amount of exudation be not great, it suffices to prescribe a small dose of calomel (1/6 OR 1/3 grain) taken every two hour, and inunction of the forehead with mercurial belladonna ointment. According to the quantity and rapidity of the exudation, the mercurial treatment must be more or less active.

When plastic iritis takes the character of parenchymatous iritis, or if the disease assumes this form at first act, being accompanied with violent inflammatory symptoms and with the rapid production of a great quantity of exudation, it is better to use at once ¾ grain doses of calomel every two hours, and inunctions with 15 to 45 grain of mercurial ointment, repeated several times a day with the usual pre cautions to avoid salivation. During this treatment the patient should be confined to bed, or at least to his room, so as to avoid sudden variations temperature.

Under the influence of this treatment we often see plastic exudations softened and gradually absorbed. If the disease is the effect of syphilis, this treatment must be followed by the administration of bichloride and opium pills, or by protoiodide of mercury, combined with iodide of potassium. In rheumatic iritis we have to employ salicylate of sodium or iodide of potassium.

In every cases of iritis, when, notwithstanding the therapeutic agents, complete posterior synechia is formed, with or without occlusion of the pupil, we must have recourse to iridectomy. This operation has also been recommended whenever there is a well-marked hypopyon. But in this case paracentesis of the anterior chamber, made with a small linear its inferior margin, is sufficient to relieve the anterior chamber ot its contents, which may be again very speedily renewed and necessitate repetition of the paracentesis.

It is often useful to employ hot compresses in such cases, which also seem to be very beneficial for the inflammatory symptoms of parenchymatous iritis, as they aid in the absorption of nodosities and gummatous tumors of the membrane. When a gummatous tumor is developed to a great size, a portion of the iris so affected may be advantageously excised.

In traumatic iritis, caused by the presence of a foreign body in the anterior chamber, our treatment should begin by removing it according to the rules already laid down (p. 59), and the secondary inflammation of the iris must be treated according to its nature and intensity. When the inflammation arises from the swelling of a traumatic cataract, we must, under all circumstances, extract the cataract by the linear method.

. in the cases of prolapsed iris, caused by a perforating wound of the cornea, we must carefully excise the portion which project beyond the level of the cornea, use atropine, put on a compress and bandage and, if the inflammatory condition of the eye require it, apply a few leeches to the temple.

Iritis supervening after the extraction of cataract may have various causes. It requires a special treatment according to its form, and according as it results, either indirectly from an inflammatory condition of the wound, from injury of the membrane during the operation, or from the action of cortical pieces remaining in the eye, or again from some individual condition of the person operated on(anemia and senile marasmus). In the great majority of cases, antiphlogistic treatment is undoubtedly prejudicial. A well-fitting compress and bandage, hot compresses, atropine, mercurial treatment, and a strengthening and tonic diet should be resorted to, according to special indications which we shall explain in the chapter on accidents following the operation for cataract.

The treatment of sympathetic iritis will bee indicated when we come to consider the sympathetic affections of the eye. After recovery from iritis, we must take precautions against relapses by using atropine continuously for a few weeks longer, even although a cure has been affected without leaving any synechiae.

If such exist, we must try first of all destroy them by instillations of atropine and of pilacarpine. In cases where we do not succeed, relapses, and perhaps the ultimat loss of the eye, can be avoided only by performing the operation of corelysis or of iridectomy. This last operation is always indicated in cases of complete posterior synechia; and in such cases surgical interference should not be abandoned of delayed.

Moreover, in all cases of iritis where the cause is noy some passing influence, the constitution of the patient should be studied, so as to prevent relapses by administration of appropriate remedies. Besides the special indications furnished by the presence of a diathesis, menstrual affections, ect., we should recommend the regular application of counter-irritants to the skin, such as dry cupping at the nape of the neck or mustard to the limbs, freeing of the urinary secretion by diuretics, e.g., mineral waters, and that of the skin by diaphoretics. All these remedies, combined with a moderate diet, are of utility in preventing relapses, in retarding the spread of the chronic inflammation to the surrounding parts endangered, and often in arresting the progress of this disease so destructive to vision.

ART.III.- Wounds of the Iritis.

Wounds of the iris are caused by the penetration of a foreign body, or a sharp-pointed or cutting instrument; or, again, by general contusion of the eye. In the first case, the body implanted in the iris may become encysted by effusion of plastic lymph, and may remain for a long time in the parenchyma without exciting inflammation. But in the great majority of cases, it is followed by an immediate and continuous irritation, which may give rise to a supperative inflammation. It is then necessary to extract the foreign body, either directly or by excising the portion of iris which envelopes it.

In searching for its situation, we may be guided by the cicatrix of the wound of the cornea, by which the foreign body entered the eye, and which is not always easily found without a careful examination by focal illumination. Again, the pericorneal injection is often greatest near the part of the corneal margin which corresponds to the position of the body in the iris.

Punctured wounds, incisions, and rents in the structure of the iris are almost always accompanied by escape of blood into the anterior chamber, which may make the examination of the affected parts exceedingly difficult.

The wound may be a simple fissure in the iris, or a loss of substance more or less considerable, rupture of the adherent border, or a rent in the papillary border only.

This kind of injury, which, form the lesion of the sphincter of the iris, produces great dilatation, is less frequent than rapture of the ciliary margin ( iridio-dialysis). It is very easily recognized, especially when we use an ophthalmoscopic mirror. A second peripheral pupil is formed, which to ordinary inspection appears black, and though which the fundus of the eye may be illumined as by the normal pupil. Similar cases have been recorded in there was even monocular diplopia.

A simple lesion of the iris alone is not followed by serious symptoms; it is often passed off, like incisions or excisions of a portion of the iris in operations, with scarely a symptom of irritation. At other times, the signs of inflammation are very slight, and yield to the use of atropine, moderate antiphlogistic treatment, and a compress and bandage.

Yet a serious inflammation of the iris, complicated by an affection of the ciliary body, may be the result, especially in cases of extensive rupture of the ciliary margin. It is, however, rare that the lens is not injured at the same time as the iris by such serious wounds. It may be dislocated or its capsule opened, in which case we have a traumatic cataract, with more or less swelling of the cortical substance. The iris, exposed to the danger of contract with these masses when they fall into the anterior chamber, or to prolonged pressure, may become the seat of a more or less serious inflammation. We are therefore obliged to extract the lens immediately, making also, in the majority of cases, an iridectomy.

When the wound in the cornea by which the instrument has entered the iris irregular, there may be a prolapse of the iris in it. Attempts at reduction of these hernias of the iris are almost always unsuccessful, and are especially dangerous. From the irritation which they produce .it is better at once carefully to excise the portions of the iris which project into the wound.

Changes in the iris, produce by general contusion of the eye, may be confined to a simple paralytic dilatation of the pupil (mydriasis), or we may find tremulous iris when the violence of the blow has cuased dislocation of the lens. At other times, we may find the iris torn away from the ciliary body (irido-dialysis) with escape of blood into the anterior chamber. These contusions may be followed by glaucomatous tension, which requires eserine, paracentesis of the anterior chamber, or iridectomy.

As a curious and exceeding rare result of such injuries, there has been observed the inversion backwards of the papillary margin; in which case the iris is driven backwards, and a variable portion of it thus becomes invincible in its entire extent. Ate the same time, the lens is generally moved from its normal position. In violent contusions, other portions of the eye are also more or less affected ( rupture of the choroid, separation of the retina, escape of blood into vitreous body), and the safety of the eye is endangered by other lesions than that of the iris. Inflammations of the membrane which follows injury should be treated by antiphlogistic remedies, according to the rules already laid down.

ART. IV. – Tumors of the Iris.

Tumors of the iris are infrequent. Cysts, on focal illumination, appear as round semi-transparent tumors, which increase more or less slowly in size. The signs of irritation which accompany them ( pericorneal injection, lachrymation, ciliary pain) are sometimes very acute, at other times they are entirely absent. Cysts are found in consequence of wounds where a hair has penetrated into the anterior chamber, and it seems probable that in these cases the development of the cyst is intimately connected with the presence of epidermis cells near the root of the hair ( Schweigger). When they give rise to pain or other inconvenience by their size, they have to be removed along with the piece of iris in which they are situated; recurrence is frequent. Cases of TUBBERCULOUS and more rarely LIPOMATOUS, PIGMENTED tumors have been noted, as also TELEANGIECTIC tumors of the iris. Condylomata and gummatous tumors have been described with parenchymatous and syphilitic iritis.

As to SARCOMA, it has been observed in the iris most frequently as an extension of the disease from other structures of the eye, generally from the choroid, yet MELANOTIC tumors have also been seen originating in the iris in the form of a red or yellowish pigmented neoplasm, which soon fills the anterior chamber and produces ulceration and perforation of the cornea. At other times the tumor penetrates beyond the circumference of the cornea, and extends into the episcleral tissue. In any such case, whenever we have arrived at a sure diagnosis, we must enucleate the eyeball.

ART. V.- Functional Disease of the Iris

Movements of the iris are either dilation or contraction of the pupil; it is contracted (a) under the influence of the light; (b) when vision is adopted for near objects; (c) when the internal rectus contracts; (d) an irritating the sensory branches of the fifth pair, especially those which supply the eye. Again, the pupil of one eye, even of a blind eye, contract when that of the other eye contracts from any of the specified causes. It is, therefore, necessary to examine the pupillary movements of each eye separately, whilst the other eye is kept shut.

The affections of the mobility which we shall have to describe here are characterize by permanent dilatation (mydriasis) or contraction (myosis) of the pupil, or by the rapid succession of contraction and dilatation, known under the name of hippus.

1. MYDRIASIS.

The dilatation of the pupil varies in degree and is sometimes irregular. When the mydriasis is very marked, the pupil, instead of remaining black, has a grayish appearance, due to the reflection in the lens of the greater quantity of the light which enters the eye.

The difficulties of the vision in which ensue in great part depend on the dazzling produced by the too great quantity of the light which enters the eye; they consequently disappears as soon as the patient looks though a small circular stenopaic opening (fig.52). Sometimes they are caused by the simultaneous paralysis of accommodation, for paralysis of the ciary muscle often accompanies that of the sphincter of the iris. We can satisfy ourselves that the difficulty in vision proceeds from defective accommodation by using bi-convex glasses, which cause it to disappear. The details of these symptoms vary with the state of the refraction of the affected eye; they will be explained along with the anomalies of refraction and accommodation.

Mydriasis is present often in one eye only; nervetheless, it is very annoying to the patient, because the retinal image affected eye differs in intensity of illumination from that of the other eye.

According to the cause which has produced it, mydriasis comes on more or less rapidly; sometimes it disappears spontaneously, at other times under the influence of treatment; but it may return, and even persist throughout life.

The prognosis also depends on the cause; it is perfectly favorable when our treatment can reach the exciting cause, or when it is not a nervous symptom indicating the presence of a serious lesion. The prognosis is very serious when the mydriasis is a symptom of organic disease of the nervous centres.

Functional affections of the muscles of the iris maybe caused – 1, by more orless complete paralysis of the third pair, of rheumatic, syphilitic or central origin; 2, by irritation acting on the great sympathetic; for instance, in spinal diseases; in telminthiasis, hypochondria, hysteria, as a forerunner of certain forms of monomania, and, through not constantly, in irritable persons, after frights, gastric disturbances, etc.

In absolute amaurosis, the dilatation of the pupil is due to insensibility of the retina to light. It has also been seen to persist after excessive use of atropine where the iris has become atrophied.

Mydriasis is sometimes due to the direct action of a swollen cataract on the muscular fibres of the iris, or again to an increase of intraocular pressure acting on the ciliary nerves (glaucoma).

In the last-mentioned case, the mydriasis may affect only a portion of the papillary margin, when a few ciliary branches alone are injured.

Treatment. – we must ascertain the cause, and if it lies outside the eye, use appropriate remedies. Locally, contraction of the pupil may be obtained by instillations of pilocarpine of eserine of the strength of 5 centigrammes to 10 grammes of water (1 to 200). At the same time, the continues current may be employed for a long time during the night (one or two cells of trouve or of leclanche; the positive pole being kept to the eyelids y a bandage, the other applied to the nape of the neck).

It is often beneficial to arouse indirectly the action of the sphincter of the pupil by exercising the vision on near objects, and regularly using convex glasses, the choice and use of which will be explained along with the treatment of paralysis of the accommodation.

Cases in which the mydiasis has been cured by administration of mercurials and of iodide of potassium are explained by the existence of a syphilitic or rheumatic diathesis as the primary cause of the paralysis of the third pair, and demand a close examination of the general condition of each patient.

2. MYOSIS

Myosis consist in the contraction of the pupil, which may be reduced in size of a pin head; less light then enters the eye, the retinal images are less brilliant, and thus vision is impaired, especially in the evening. The presence of myosis has a little effect on the extent of the visual field; consequently, by itself, it does not causes much disturbance of vision. When that exists, it should be attributed to other concomitant alternations.

The causes of this affection may be ranged into two classes – those which cause spasmodic contraction of the sphincter of the iris, and those which produces paralysis of the fibres of the dilating muscle. To the first class of causes, we must assign myosis resulting from the brilliant objects (this form is apt to occur amongst jewelers, watchmakers, engravers). To this class we must also refer the myosis produced by the reflex action which the sensory branches of the fifth pair exercise on the common motor oculi, which explains the sluggish pupil in ciliary neuralgias, when a foreign body or other irritating influence acts on the corneas or conjunctival sac. Lastly, central irritation of the third pair may cause spasm of the sphincter (meningitis in its early stages, congestion of the encephalon from alcoholic excess, opium, nicotine, ect.).

Pilocarpine and eserine, by an influence directly opposite to that of atropine, produce myosis by their effect on the nerves of the iris.

Myosis due to paralysis of the dilating fibers indicates an alternation in the sympathetic – as, for example, in the form of spinal amaurosis, which accompanies locomotor ataxy. In this affection, the diameter of the contracted pupil doen not vary with illumination, but continues to be modified with convergence and the accommodation ( Robertson ) . myosis has also been seen to follow compression of the cervical sympathetic, from tumor or an aneurism.

The treatment of myosis should vary with its cause, which, as we have just seen, is often at a considerable distance from the eye. As local treatment, we should mention the used of atropine; but the effect of this remedy only lasts for a short time, and it should be considered as a rational remedy only for spasm of the sphincter of the iris, for which it should be employed systematically.

3. HIPPUS

Hippus is characterize by incessant changes in the size of the pupil, which contracts and dilates successively, and independently of such physiological causes as light, accommodation, ect. It is observed during recovery from paralysis of the third pair (analogous to the irregular contractions of other muscle during the regressive period of paralusis), as a consequence of albinism, and most frequently as an accompaniment of the chronic convulsions of the extrinsic muscles of the eye, known as nystagmus.

The trembling of the iris (tremulous iris, iridodoncrosis) is purely a passive movement of the membrane, produced during the movements of the eyeball whenever the iris has lost its natural support – viz., the anterior convexity of the lens. This trembling may also be seen to affect a portion of the iris only, in cases of partial dislocation of the lens. Most frequently this phenomenon supervenes after the extraction of cataract, after complete displacement of the lens, either from its falling down, or from injury. Again we find it when the lens has perceptibly diminished in volume, by partial absorption ( in catarqacts more than ripe, or after operations by discussion).

It is also seen in cases of anterior hydrophthalmia, when the iris is drawn forwards by the distention of the anterior portion of the eye, and separated from the lens by a layer of fluid.

Contrary to the hitherto generally received opinion, we do not think that fluidity of the vitreous alone can produced tremulous iris, for with the ophthalmoscope we have seen many cases of complete liquefaction of the vitreous, where there was no movement of either the lens or eris from before backwards.

ART. VI.- Congenital Anomalies of the Iris.

Color.- Various anomalies in the color of the iris are seen, in the iris of one eye not being of the same shade as that of the other, without there being the least disturbance of vision. We must take care not to confound this condition with discoloration produced by iris. Again, the iris may not be of the same color throughout, and the difference of shade may be confined to a section of the membrane or to the small circle. Besides, we may notice pigmentary spots on the iris, varying in number, in size, and in their generally very dark color. All these peculiarities are without pathological importance.
Irregularity in form of pupil.- Another variety of congenital anomaly consist in irregularity in the form of the pupil, which is often nearly oval. In many cases also the position of the pupil is marked eccentric. Moreover, in most eyes the centre of the pupil is not situated exactly behind the cornea, but rather to the inner side, at the point corresponding to the visual axis of the eyeball, and in such cases the displacement of the pupil may pass unobserved. But the pupil may be situated very far from the centre (ectopia0, in which case it is separated from the adherent border of the iris only by a narrow band of that membrane. The lens may also be similarly displaced. Ectopia is often found in both eyes symmetrically and in several member of the same family.
Multiplicity of Pupil (polycoria) is very rare. The abnormal pupil may be in the neighborhood of the normal pupil, separated the other from the other by narrow bands of iris tissue (probably in connection with persistence of the papillary membrane). At other times there is a complementary opening near the ciary the margins of the pupil are free. As a rule, there is no difficulty of vision arising from this anomaly, which may, however, cause diplopia.
Persistence of the Pupillary Membrane is less infrequent; it is usually incomplete, in so far as only a greater or smaller number of fibres are seen, arising from the anterior surface of the iris, and crossing the pupil; or they unite to form a pigmented membrane in front of the capsule.

They do not at all impede the normal action of the pupil, afford the luminous rays a passage sufficiently great to prevent any alternation in vision.
in Coloboma of the Iris we have a fissure of the membrane almost invariably directed downwards and inwards. It may extend across the whole iris (complete coloboma), or stop short at a certain distance from the ciliary margin (incomplete coloboma). In the latter case (fig.53), tha margin of the coloboma sometimes contract with the pupil, although they do so more slowly.
The fissure of the iris often extend to the ciliary body and choroid. Sometimes, in connection with coloboma of the iris, we find microphthalmia, congenital cataract, and other fissures which should have closed during intra-uterine life (colobama of the iris may be found in one or in both eyes; it has been often noticed in several members of the same family.

When the iris alone is affected, vision is almost always normal; cases of amblyopia occur along with the complications which we have mentioned.

Coloboma is due to an arrest of development of the eyeball.
Absence of the iris (trideremia of aniridia) may be complete or incomplete. If the letter, we find irregular portions of the iris tissue, of variable size, absent; or the small circle only may be wanting, which gives the appearance of a pupil dilated with atropine.

When there is complete absence of the iris, the lens can be seen in its entire extent, and the eye has strange aspect. If cataract supervene, vision may be sufficiently good, in consequence of light passing between the margin of the lens and the ciliary body.

In general, patients suffer only from dazzling, and any greater disturbance of vision depends rather on complications (buphthalmos, cataract, microphalmia, ect.).

When the ciliary muscle is also absent, accommodation is imposible. Absence of the iris has been observed in both eyes, and seems to be hereditary in some families; it also is due to an arrest of development in the eyeball. In cases of dazzling, we may advantageously prescribe smoked glasses and stenopiac spectacles.

ART. VII.-Anomalies in the Form and Contents of the Anterior Chamber

Even in the normal state, the depth of the anterior chamber varies considerably, according to the age of the person and the condition of the refraction of the eye. It is shallower in infants and in old people in adults, deeper in myopic eyes, in which the eyeball is elongated, than in hypermetropic.
In consequence of pathological conditions, the anterior chamber may become shallower or deeper. The first modification is due to flattening of the cornea (consequent of cicatricial contraction) or on the iris being kept forwards either by anterior synechia or by exudations accumulating behind an iris affected with complete posterior synechia. The peripheral part of the anterior chamber may be deeper than the central, when fibrous bands bind the great circle of the iris to the ciliary processes. Again, the anterior chamber is greatly diminished in depth when there is an increase of the intraocular pressure (glaucoma) pushing the lens forwards towards the cornea, or when the lens itself, increasing in size by the softening of its substance, pushes the iris nearer the cornea.

The anterior chamber increase in depth in cases of staphyloma of the cornea, or by the distention of the anterior portion of the eyeball (hydrophthalmia), or again when the lens is displaced in the eye or removed from it.
The contents of the anterior chamber may be with blood, with pus, with foreign bodies, with lens tumors, cysticercus, etc.

Effusion of blood into the anterior chamber has been called hyperemia. When the anterior chamber is entirely filled, we perceive a effusion only occupies a portion of the chamber, we may displace its usually horizontal level, by moving the head, so long as the blood, we see a layer of aqueous humor of a rose color. The portion of the iris which remains visible seems at first to be of its normal color, later it becomes discolored, as in hyperemia. The pupil sometimes dilated by the pressure which the blood exercises on the iris.

The disturbance of the vision, always very great when the anterior chamber is filled with blood, depends in partial effusions on the amount of difficulty with which the light still penetrates the eye, and on the causes to which the effusion s due.

It is due in most cases to injury, contusion of the eye, or detachment of the iris from wounds or operation. It is, as a rule, quickly absorbed, and without any other treatment than the application of a compress and bandage. But we also observe persistent hemorrages, or hemorrhages which are renewed several times during a fortnight, the clot which closes the torn vessel of the iris being always again detached by the action of the aqueous humor. We can then recognize the recent effusions by the fresh appearance of the blood, whilst the absorption leaves on the iris very dark colored red spots.

When the quantity of the blood effused is very great, and is acting on the iris like a foreign body, producing symptoms of irritation (pericorneal injection, ciliary pain, etc.), we are obliged to remove it from the anterior chamber by performing paracentesis at the lower margin of the cornea. But this small operation requires great care, as the withdrawal of pressure may cause fresh hemorrhage, arising from the vessel torn in the primitive lesion. The contents of the anterior chamber should be allowed to escape very slowly; whilst slight digital pressure is made on the eyeball through the superior eyelid. This pressure should be maintained by tight bandage, applied immediately after the evacuation of the anterior chamber. It may be gradually slackened after a quarter of an hour, but the pressure should be continuing by the application of an ordinary bandage for several days.

A second cause of effusion of blood is certain internal inflammations of the eye, such as chronic choroido-iritis, with occlusion of the pupil and commencing atrophy of the eyeball. In these cases, the hemorrhage may return, and is with difficulty absorbed. Here, while paracentesis is useless, a bandage promotes absorption; but our treatment should be directed to the deeper disease of the eye.

We must also notice isolated cases of spontaneous effusion of blood, due to disturbance of the general circulation, connected with dymenorrhoea, purpura haemorrhagica, etc, and again, those curios instances of patients who at will can produce an effusion of blood into the anterior chamber (Weber, Mooren)

The effusion of plastic lymph or of pus into the anterior chamber, termed hypopyon, is most frequently connected with affection of the cornea (three times out of every four), or of the iris, or of the ciliary body.

We have already described the symptoms and peculiarities of this affection, when speaking of suppurative keratitis and iritis. It only constitutes a symptom; consequently its treatment is closely connected with that of the affection to which it is due.

Portions of the lens may fall into the anterior chamber, in consequence of rupture of the lens capsule by operation or by injury.

Cases have also been recorded where the complete lens, loosened from its attachement by raptur of the suspensory ligament, has on dilatation of the pupil, fallen into the anterior chamber. (See dislocation of the lens.) In the majority of cases, the portion of lenticular matter are rapidly absorbed, and do not cause any injury. It suffices to keep the pupil dilated by atropine. If the entire lens has fallen into the anterior chamber dilated by atropine. If the entire lens has fallen into the anterior chamber, it must sometimes be removed by an incision made in the periphery of the cornea.

Foreign bodies may enter the anterior chamber through the cornea; their influence on the iris and the method of extracting them has already been explained apropos of the cornea and iris (see p.159).

Cysticercus has been seen in the anterior chamber, and more than twenty cases have been published. In general, the first symptoms are those of a circumscribed iritis, then a white spot makes its appearance, and increases in size till the parasite pierces the membrane and floats in the aqueous, or is attached to a portion of the iris.

The anterior chamber then enclosed a small semi-transparent, yellowish vesicle, endowed with undulating movements, and projecting from time to time a small filament, the extremity of which is furnished with an enlargement, representing the head and neck of the cysticercus (fig.54). the presence of this foreign body often produces a disturbance of the aquenous, and symptoms of iritis, which necessitate its removal by a linear incision in the periphery of the cornea. If the removal of the cysticercus be followed by prolapsed of the iris, which ordinary manipulation does not reduce, it is better to exercise the prolapsed portion.

ART. VIII._Operations on the Iris.

1. IRIDECTOMY.

Indications. – iridectomy is performed for a double purpose; sometimes to form a artificial pupil, sometimes in certain inflammatory conditions of the membranes of the eye as an antiphlogistic agent.

For optical purposes, iridectomy is restored to in the following circumstances:

In central opacity of the cornea;
In occlusion of the normal pupil;
In stationary central capsular cataract;
In zonular cataract or other stationary central cataracts;
In certain cases of dislocation of the lens.

As an antiphlogistic, iridectomy is performed-

For glaucomatous affections;
In a certain class of affections of the cornea;
In cases of the iritis or irido-choroiditis accompanied with adhesion of the iris;
For complete posterior synechia, or for multiple and large synechiea, which are not broken up by atropine.

Before making an artificial pupil we should always examine the state of the vision, so as to be sure that its impairment is entirely due to the opacitites which are seen on direct inspection. For this purpose the pupil must be dilated with atropine, and the visual acuteness measured by test types; we must also employ stenopaic slits and glases adopted to the state of the patient’s refraction and accommodation. When we are dealing with a leucoma adherens, which prevents our dilating the pupil, we estimate the state the state of the vision by finding the distance at which a luminous point is still seen as such. We should also examine the visual field by a lamp, so as to prevent our making an optical iridectomy in cases of amaurosis or of separation of the retina, when the patient cannot possibly gain anything from the operation (see p. 42).

In eyes where there has exited a leucoma from infancy, we often find a certain degree of insensibility of the retina. When we examine such patients we find that they do not distinguish the luminosity of an ordinary lamp, and specially that they do not indicate exactly the direction of the luminous source. They often refer all luminous impression to the temporal side, no matter from what direction they come. It is in such cases that the examination of the phosphenes is of great importance. We must also take into account the time that has elapsed since the eyesight has not been used, and repeat at short intervals our examination with tha lamps, because it helps to awaken the retinal sensibility. We can operate in those cases with confidence in the result, for we know from experience how much the vision will be improved by systematic exercise, as soon as luminous rays reach the retina, through the artificial pupil.

In answer to the question, should an artificial pupil be made in one eye if the other be perfect, we must reply in the affirmative (von graefe). In a certain number of creases the visual field, and makes it easier for the patient to go about.

Choice of the Situation for Artificial Pupil.-When we perform iridectomy for optical purpose, as, for example, in cases of leucoma, for obvious reason we must select the most transparent portion of the cornea, bearing in mind that each perfectly opaque spot is surrounded with a semi-transparency in all portions of its periphery, the operation should be performed inwards and somewhat downwards, so that the artificial pupil may occupy the position of the normal visual line. If the internal part of the cornea is occupied with an opacity, the iridectomy should be made from below; if the inferior and inner portion is affected, it must be made from below; if the inferior and inner portion is affected, it must be made from outside; and if the upper portion alone is transparent, we must make it from above, although we run a chance of seeing the pupil obscured by the superior eyelid. In cases of occlusion of the pupil, central cataract, etc., if the cornea is perfectly transparent, we always select its internal and inferior aspect.

If we performed the operation on both eyes, we always make, if possible, the artificial pupil in the same position- that is to say downwards and inwards, etc.

When the iridectomy is made to diminish intraocular tension or for posterior synechiea, it is better to make it at the superior pat of the cornea, because it is not so easily noticed and causes less dazzling.

Yet, as it is rather more difficult to perform the operation above, an inexperienced operator will prefer to choose the inferior or inernal portion of the cornea. The same position should also be chosen when the fear or indocility. The cornea has then the great tendency to rotateupwards, and when we draw it down with fixation forceps to the palpebral fissure, we run the risk of rupturing the zonule of zinn. This danger is most to be feared when the eye is very tense from excess of intraocular pressure, at the moment when we are about to excise the iris, after making an incision in the cornea.

Extent of the Iridectomy. - The size of the portion of iris to be excised depends essentially on the object of our operation. When it is a question of artificial pupil, it is important that the iridectomy be not uselessly large. A small opening suffices for the passage of luminous rays, a large one causes the patient troublesome dazzling. On the other hand, when we wish to diminish intraocular tension, or to establish communication between the anterior and posterior chambers of the eye, we must excise a large portion, involving the extreme periphery.

The size of the portion to be excised is determined by the situation and dimensions of the incision through which the iris is to pass. Thus, for example, if the incision in the cornea be situated at the place marked a, b (fig.55), the artificial pupil will occupy the area a”,b”,c”,d”.

Again, if the incision be made in the sclerotic (fig.57), and be represented by the length a “,b”, the new pupil will be bounded by the figure a”,b”,c”,d”.

In the diagrammatic figures which we have just given, we have supposed that the incision is perpendicular to the surface incised, but in reality the instrument passes more or less obliquely through the tissue, so that it is necessary to distinguish the internal wound (fig.58), a’,b’, which opens into the anterior chamber, from the external wound, a,b, on the external surface. It is evident that it is the size and position of the internal wound which determine the size of the artificial pupil, since the iris, stopped by the margin of the wound, cannot come farther out of the anterior chamber. It is for this reason that we must make the incision in the sclerotic, if we wish to excise the iris up to its ciliary attachment. The operation of iridectomy does not required only for timid and unmanageable persons or for children. We use cocaine to render the conjunctiva and cornea insensible.

For children, it is well to keep the legs and arms perfectly still by rolling them up in a shawl.

The instruments necessary for the operation are

Eye speculum (fig.59);
Fixation forceps (fig.60);
Straight of bent keratome (fig. 61 and 62);
Iris forceps (fig. 65).
Curved scissors (fig.65).

It is also well to have in readiness, in case they should be required, a probe- Pointed knife and a small straight spatula (rubber, tortoiseshell, or silver).

For elevators we use the spring speculum, or, if the patient is under the influence of chloroform, or restless, two ordinary elevators. When the patient is quite, it is better to hold the lids separate by means of the fingers of an experienced assistant. This greatly diminishes the inconvenience suffered by the patient during the operation, which inconvenience is due in great part to the pressure of elevators.

Bent or straight keratomes are used; the latted only when we make an iridectomy from the temporal side.

In every other situation, because of the nasal and orbital prominences, we must choose bent knives, the angle at which they are bent varying with the amount of prominence. The same consideration must determine the curvature of the forceps.

Description of the Operation.- In the description of the carious steps ot the operation, we supposed that the operator is making an iridectomy on the right eye at its internal aspect.

First Stage: incision of the cornea.- the patient being placed on a couch, and his head fixed by the hands of an assistant, the operator, having sufficiently separated the lids, lifts with the fixation forceps, held in the left hand, a fold of conjuctiva near the margin of place where the coloboma is to lie, temporal side, he introduces the knife into the anterior chamber, at the place previously determined in accordance with the special features of the case. As soon as the point enters the anterior chamber (fig.66), it should be directed towards the centre of the pupil, so that the Knife is always in a plane parallel with that of the iris. When we have made a sufficiently large opening, and wish to begin to withdraw the knife, it is of the utmost importance to lower the handle of the instrument, so that its point is directed towards the cornea. This precaution is necessary, because this is the time at which the aqueous usually escapes; the lens and iris are pressed forward, and if the knife maintained its original position, its point would inevitably injure the lens. When we have given the knife the position indicated, it is slowly withdrawn from the anterior chamber, care being taken by lowering the handle always to keep the knife towards the cornea. At the same time, we may, if necessary, enlarge the wound by drawing the cutting edge along one of the angles of the incision. It is only at the last moment, when the point is very near the corneal wound, that we must give the knife the same position that it had at the beginning of operation.

If we have selected the cornea for our incision, we must take care not to run the knife to far between its lamelle. Also , the advice is generally given to make the point of the knife enter perpendicularly to the surface of the cornea; in which case the handle of the instrument must be lowered as soon as the point enters the anterior chamber, so that the knife may be parallel with the iris when in the anterior chamber.

It is better to give the knife the direction which it should have in the anterior chamber, even from the beginning of incision; we then select a spot for the puncture a little further back, and, before puncturing, we make a slight depression on the cornea with the point of the knife.

It has been sometimes advised to withdraw the knife abruptly, but the sudden diminution of intraocular pressure may cause congestion of the vascular tissue. It In this Fig. the fixation forceps is not on its right place: it ought to be higher up, opposite to the point of the knife. Is therefore, preferable to withdrawn the knife slowly, so that the aqueous may escape as gently as possible from the anterior chamber.

When the incision is not sufficiently large, it may be increased by means of a small blunt-pointed knife (Fig.67) or with scissors. Considerable caution and great dexterity are required in using scissors for this purpose.

The section of the cornea can be performed also by puncture and counter-puncture with von graefe’s knife in the same way as in the operation of cataract (see Chap.IX.), when the anterior chamber is narrow. In these cases, when the periphery of the cornea has to be spared for optical purposes- as, for instance, in large central leucoma- Gayet performs the incision of the scleral margin with scarificator, cutting in horizontal line the layers until the anterior chamber is opened; then he passes the blunt-point knife or scissors to enlarge the opening.

Second stage: Section of the shred of Iris drawn out through the wound. – The surgeon, laying aside the keratome, but still keeping the eyes steady with the fixation forceps, takes hold of the iris forceps, and keeping them firmly closed, exercises slight pressure with their point on the external lip of the wound, and thus introduces them into the anterior chamber.

He directs the point towards the papillary margin, taking care by slight lateral movements to prevent the instrument from becoming entangled in the folds of the iris. Having got to the margin of the pupil, the surgeon should steady the forceps, and having opened them he should seize hold of the margin of the iris and draw it out. An assistant then takes a pair of curved scissors, and gently laying their convex side against the eyeball, cuts of the prolapsed iris as near to the cornea as possible. (fig. 69).

Often the iris becomes spontaneously prolapsed in the wound, at other time prolapse may easily be produced by slight pressure on the sclerotic margin of the incision; in either case we require to introduce the forceps into the anterior chamber.

If the surgeon cannot avail himself of the services of an experienced assistant, to whom he mat entrust the cutting of iris, he is obliged to make over to his assistant the fixation ot the eye, whilst he himself takes the iris forceps in his left hand, and uses the curved scissors to cut the iris with his right.

However the iris may be cut, it is necessary that it be cleanly cut at the level of the cornea. If otherwise, a piece of prolapsed iris may be left in wound, which will be drawn into the anterior chamber by the contractions of the iris, or will remain included between the lips of the wound. In the first case, the new pupil will not be of the size which we wish; in the second case, a synechia will be formed.

The necessity of carefully excising the iris from its ciliary attachment in glaucoma cuts with scissors. He begins by excising the shred of the iris at one angle, detaches it from its insertion, and finishes by a last cut with the scissors at the other angle; but he has to take care not to draw the iris strongly into the angles, where it gets entangled and cannot be pushed back without difficulty.

Third Stage: Clearing the wound.- This is accomplished by management designed to removed any effusion of blood, and to disengaged the sphincter of the iris from the margins of the wound.

When there is effused blood in the anterior chamber, we try to evacuate it as much as possible by opening the lips of the wound with a narrow spatula (fig.71), at the same time making light pressure of the sclerotic margin of the wound.

The aqueous humor which thus escapes from the anterior chamber carries the blood along with it; this delicate manipulation may be repeated several times at intervals. Yet, if the blood show no tendency to come out, or if there be a be a renewal of the hemorrhage, it id better to put cold-water compresses on the eyelids, and to refrain from any further attempts at evacuation, for the absorption of blood takes place in a very short time (almost always during the first twenty-four hours).

In clearing the wound, we removed with small forceps the little blood clots which are formed on the conjunctiva at the incision, then any particles of iris pigment retained between the lips of the wound. For this purpose we cause the convexity of the curved scissors to glide over the margin of the wound, sliding the instrument from the periphery of the cornea towards the sclerotic.

In the place we must assure ourselves that the margins of the iris are not between the lips of the wound. We may detect their presence in the anterior chamber by seeing the margin of the artificial pupil formed by the extremities of the cut sphincter. In cases where the extremities of the sphincter have not entered the chamber, we must cause the spatula or the back of a caoutchouc curette (fig.73) to slide over the sclerotic to cornea, making slight pressure at the margins of the wound, or we may gently push them into their place with the spatula. This manipulation should not be stopped till we have obtained the desired result.

When we are satisfied as to the condition of the wound, we refresh the eye on which we have operated by applying cold compresses for a few minutes, or sponging it with cold water; we then apply a compress and bandage.

As a rule, all pain causes with the application of the bandage, which should be changed for the first time not sooner than twenty-four hours after the operation.

A few drops of atropine the day after the operation, ensure, by dilating the pupil, that the edge of the newly-cut sphincter do not contract any adhesions with the capsule. The tendency to the formation of posterior synechiae may be inferred if the corner of the cut sphincter takes the form of projecting angles. If this feature be absent, and if the progress of the eye be favorable, atropine is not used till the third day after the operation.

We seldom have any great reaction in the eye after iridectomy, so that it suffice to continue the application of the bandage for a few days, and to keep the patient in bed in a dark room till the small incision is completely cicatrized. Whenever this takes place the patient may wear a loos bandage, and gradually accustom himself to broad daylight, protecting his eyes, when he begins to get out, from excessive light by smoked glasses. If there be a pronounced reaction, it may become necessary, when the irritation appears in the neighborhood of the cicatrix, and when the cicatrix is still very thin, to continue the application of the bandage for a longer period. If the aqueous humor is muddy, and if there are symptoms of iritis, we must follow the course indicated when speaking of this disease, especially insisting on the use of atropine.

When there is pain or sleeplessness we must have recourse to chloral or subcutaneous injections of morphia, and if the pain persists, we apply several leeches behind the ear of the same side. All such complications naturally indicate a prolonged period of rest in a darkened room.

2. SUBSTITUTES OF IRIDECTOMY.

Iridotomy.-In cases in which the lens is absent-e.g., after cataract operations, when there is occlusion of the pupil in consequence of iritis, even in cases where there has been an irido-cyclitis, with disorganization of the iris tissue and flattening of the cornea- von graefe substituted iridotomy for iridectomy. He followed one or two methods in performing this operation. The first method consist in pushing a small double-edged and very sharp-pointed knife through the cornea and newly-formed tissues, till it reaches the vitreous humor, and then immediately withdrawing it in such a way as to enlarge the opening in the plastic membranes without increasing the corneal wound. According to the second method, he introduces a small sickle-shaped knife through the margin of the cornea, piercing the iris and vitreous humor. He then divides the iris from behind forwards, and withdraws the knife. The opening thus made in the iris in enlarged by the retraction of the tissues and penetration of vitreous; it shows less tendency to be obliterated than after iridectomy performed under the same conditions, which is no doubt due to the greater simplicity of the operation, iridotomy almost never causing effusion of blood or dragging of the tissues involved.

Bowman has proposed iridotomy for optical purposes even in presence of the lens-for example, in zonular cataract. He punctures the cornea near its external margin with a narrow iridectomy knife, and introduces through this opening a small convex probe-pointed knife of the same size as the iridectomy knife. The point should traverse the pupil between the iris and the lens, and be carried on till it reaches the ciliary attachment of that membrane. He then turns the blade towards the iris, which he cuts at its papillary border in withdrawing the knife. It is difficult to avoid incising the posterior surface of the cornea at the same time; but the greatest danger is the chance of opening the capsule of the lens in introducing the knife between it and the iris.

De Wecker’s forceps-scissors are very useful in performing iridotomy. Should the lens be absent, we make a small incision with the iridectomy knife near the margin of the cornea, piercing both it and the iris. Having introduced one of the blades of the scissors behind the iris, and the other between it and the cornea, reaching to the opposite margin of the cornea, one or two incisions are made (iridotomy simple or double), according to the case with which the tissues retract so as to form a sufficient pupil.

As we cannot always use this instrument without a considerable loss of vitreous, and as the action of the scissors involves a certain degree of contusion, it is better in most cases to use Sichel’s iriditome (Fig.74), which incise the iris from before backwards, according to the original proposal of von Graefe. The special indications of these operations will be explained in greater detail when speaking of secondary cataract.

Another method of forming an artificial pupil for optical purposes(in cases of central opacity of the cornea or lens) is that of Carter. Having made a small incision at the corneal margin, he introduces into the anterior chamber a pair of scissors, the blad3es of which are shut. On opening them a small fold of iris gets between them, which is excised by closing them. The small piece of iris often remains on the scissors, and may be removed by withdrawing them from the anterior chamber; if not, it must be extracted by iris forceps.

Iridorhexis.-When the iris, in consequence of chronic inflammation, is vary brittle, if there be adhesions of the papillary border, these synechiea are sometimes tougher that the iris tissue itself.

If, then, we perform iridectomy, on taking hold of the iris with the forceps, it often happen that we find the iris tearing in its continuity, rather than its pupillary margin separating from the capsule. An experienced observer can, by careful examination with focal illumination, to a certain extent foresee this state of matters, the surgeon who would then free the margin of the pupil from the capsule, might by to great traction tear the capsule, and thus run the risk of traumatic cataract.

To prevent this accident, desmarres invented a process for tearing the iris, rupture of which is inevitable in these cases. Iridodesis, Iridenkleisis.- when we make an iridectomy in the usual manner, we exercise the sphincter of the iris, and the artificial pupil is of course deprive of its mobility at the spot where the sphincter is cut. This condition is not without inconvenience to the patient, when the iridectomy is made for optical purposes.

On this account various attempts have been made at displacing the normal pupil, so as to intercept as much as possible the luminous rays traversing the defective portions of the cornea and lens, at the same time preserving for the new pupil all the mobility of the old.

This desideratum has been obtained by the following process devised by Critchett: a very narrow incision is made with a narrow iridectomy knife, or with a special instrument, the broad needle, at the margin of cornea, or, better still, in the sclerotic. The thread noose previously prepared, and kept open, either by the ingenious forcep of Waldau or those of Forster, or by means of a somewhat large pair of ordinary forcep, is then placed over the incision in such a manner that the surgeon may pass a pair of very fine iris forceps through the noose and incision, so as to take hold of the iris at some distance from the margin of the pupil.

He then draw out the iris, taking care to leave the sphincter in the anterior chamber, and the noose is closed round the small prolapse of the iris, either by means of the forcept or by tightening the end of the tread. In this way the iris is ligature (iridodesis). The surgeon then cuts the ends of the thread at a little distance from the noose, and applies the ordinary compress and bandage.

After two days, when the small wound has cicatrized, the prolapsed portion of iris is cut of along with the noose, which strangeit.

Snellen has simplified this operation by passing, previous to making his incision, a tread through the conjactiva, parallel with the margin of the cornea, and as near as possible to the point of puncture. The tread being so arranged, it only remains after the incision to make the noose, through which the forcep are passed, and to tie it tighly over the small prolapse.

Stellwag and de Wecker have proposed to replace ligature of the iris by simply causing it to be embraced in the cicatrix of the wound of sclerotic (iridenkleisis).

For this purpose, an incision is made a little farther from the margin of the cornea, piercing the sclerotic very obliquely, so as to obtained a sufficient long canal. The prolapse of the iris is effected by gentle pressure on the external lip of the wound, or if necessary the iris is drawn out by a very fine iris forceps as in eridosis. When once the iris has prolapsed, it is not touched, but the compress and the bandage are put on, and left untouched for twenty-four hours, at the end of which time, the small portion of iris which protrudes beyond the sclerotic is cut off with curved scissors.

A more simple means of obtaining the same result consists in fixing the iris in the sclerotic wound, finishing the operation at one sitting.

For this purpose, a peripheral incision is made in the sclerotic, the iris is drawn out so as to leave the sphincter in the anterior chamber, and the portion of iris which protrudes beyond the sclerotic wound is immediately resected with a pair of scissors.

If the canal of the wound be narrow and sufficiently long, the iris remains caught in it. As soon as the section of the prolapse is completed we apply a pressure bandage.

Notwithstanding the considerations which have led to the invention of displacement of the pupil, this operation has never been generally adopt, because there is a danger that the dragging of the iris, caught in the sclerotic wound, will at a later period become the starting-point of chroinic inflammations. Several cases of irido-choroiditis, arising form this operation, have been published, some of which have ended in the loss of the eye.

Corelysis.-In cases of synechia, it has been attempted to free the iris from its adhesion by detaching the papillary margin from the lens by means of an operation (Streatfield and Weber).

It has been proposed to do so in the following manner;

First Stage: Puncture of the Cornea.- A small incision is made in the cornea, at about 4 millimetres from its centre and in its external portion, by means of a paracentesis needle or a broad needle. This incision should be about 4 millimetres in breadth.

Second Stage : Freeing the Pupilary Margin from the Lens.-We may use for this purpose Streartfied’s spatula (Fig.75) or Weber’s hook (Fig.76). The spatula is introduced through the corneal incision into the anterior chamber, laid flatly on the lens, and gently pushed forwards between the iris and the capsule, at the side of the synechia which we wish to destroy (Fig. 77).

Slight lateral movements are then made with the spatula in the direction of the synechia, taking the cornea as the point of support, and holding the handle of the instrument in the horizontal plane. As a part of the synechia yields, the spatula should be made to advance farther on the papillary margin.

In this way we may, by moving the instrument in different directions, detach almost the whole of the border of the pupil, with the exception of the parts beneath the section and its immediate neighborhood. Therefore, we must make the corneal incision in front of that portion of the pupil which is most free.

If circumstances allow a choice, we should make the corneal incision by preference in the external portion of the cornea, there being no bony prominence to interfere with the necessary manipulations. Having finished the operation, we must immediately dilate the pupil, and maintain the dilatation by frequent instillations of a strong solution of atropine or duboisine.

Another method of performing corelysis has been proposed by Passavant. He makes a small incision with an iridectomy knife near the margin of the cornea just above the synechia.

The size of the incision is such as to easily admit iris forceps; he introduces a pair of small forceps, without sharp points, into the anterior chamber, and takes hold of the iris; he then destroys the synechia by gently withdrawing the instrument. As soon as the synechia is destroyed he opens the blades, so as to let the iris go, and carefully withdraws the instrument from the anterior chamber. He can only detach on synechia at a time, and if there are more than once he must repeat the operation, which he does after a few days. If there be prolapse of the iris in the corneal wound, he attempts to reduce it by the ordinary method Forster detaches the synchia by pressing with the finger and the margin of the eyelid through the cornea upon the pupilary margin, and pushing it back towards the periphery of the anterior chamber, having first let out the aqueous humor by paracentesis

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