The Indian operation of couching for cataract

by Robert Henry Elliot

Glaucoma.

It has long been known that couching is frequently followed by secondary glaucoma. In the present series of 54 globes, 19 of them showed evidence of high intra-ocular pressure. This figure must not, however, be taken as a reliable index of the numerical frequency of glaucoma as a complication of the operation. On the one hand, we must remember that the present series deals with the failures only, and that a large number of eyes are met with clinically in which the lens is floating free in the vitreous chamber without any sign that the intra-ocular tension is raised. Again, the cases which go on to suppuration, and which are very numerous, are excluded from the present series owing to the fact that all such were eviscerated in order to avoid the risk of intracranial sepsis. This obviously diminishes the total number of globes under consideration, and thereby raises the apparent percentage of other conditions, such as glaucoma. On the other hand, it would be a mistake to suppose that out of these 54 globes only 19 had suffered from secondary glaucoma, for in 24 of them a complete detachment of the retina had covered up any evidence which may at some time have existed of the presence of increased intra-ocular pressure, though the conditions still found in some of them make it more than probable that the globes were formerly glaucomatous. In any case, it leaves us with the fact that, out of 30 eyeballs which were available for accurate examination, no less than 19 were glaucomatous. In 17 of the 19 the angle of the anterior chamber was extensively closed, and in 3 of these the chamber was so shallow as almost to be reduced to a potential slit. The remaining 2 are thus accounted for: In one the angle was open save for a small marginal adhesion, and there was free communication between the aqueous and vitreous chambers; unfortunately, the specimen was almost spoilt in sectioning it for the microscope; in the second, a Morgagnian lens was impacted in and had blocked the angle of the anterior chamber.

Returning to the 17 cases in which the angle of the chamber was closed, and to certain other eyeballs in which it seemed probable that glaucoma had at some time been present, we found that in every one of them one or other of the accepted causes of secondary glaucoma was revealed when looked for; in some, more than one such cause was discoverable. We shall content ourselves with enumerating these factors.

A corneal fistula, with evidence of past anterior staphyloma, was present in one; here the cause of the glaucoma was evidently the closure of the filtering angle, which resulted from the anterior synechia; in one there was a capsulo-corneal synechia (Pl. IV., Fig. [24]), and in another a retino-corneal synechia (Pl. IV., Fig. [25]); in 5 the ciliary body was involved in the scar; in 6 the dislocated lens pressed extensively on the iris base (Pl. VII., Fig. [45]); in 3 the lenses, tilted at right angles to their normal position, pressed the anterior hyaloid membrane severely back on the side of the dislocation, whilst causing the vitreous to bulge the iris forward into the anterior chamber on the opposite side; in 5 the pupil was blocked, and in 3 of these l’iris bombé was present; in 2 the anterior layers of the hyaloid were so thickened by inflammatory exudate as to suggest that there was an abnormal obstruction to the passage of fluid across the membrane; in one a marked thickening of the lens capsule in the form of an after-cataract may possibly have provided an obstruction to the forward passage of fluid from the vitreous; lastly, there is one globe in which glaucoma had probably been present before the operation, if one may judge from the history of the case and from the violent hæmorrhage which followed the couching.

It has been suggested that one of the causes of glaucoma after this operation is an advance of the front part of the vitreous body owing to a rupture of the anterior layers of the hyaloid during the operation. Without in any way denying that the suggestion may be a valid one in certain cases, the impression gained from a study of this series is that we need look no farther than the well-recognised causes of secondary glaucoma. We have only to remember that the trauma inflicted is extensive and various, and that a greater or less degree of sepsis accompanies every couching in the hands of its Indian exponents.

CHAPTER VI
DIAGNOSIS

The diagnosis of a case of couched cataract presents the surgeon with three distinct problems: (1) To ascertain whether a couching has been done or not; (2) to discover the new position of the lens and its condition; and (3) to decide whether it is advisable to operate. Only those who work in lands, where the couching of cataracts is an everyday occurrence, will take a deep concern in such questions; but the subject has a scientific interest which cannot fail to appeal to any one who devotes his serious attention to the large questions of ophthalmology.

It might be thought that the simple and obvious way to ascertain whether a couching had been done would be to ask the patient or his relatives. In a large number of cases this is of course sufficient; but in India, at all events, there are many who will deny the operation they have undergone. This is due to the fact that it is widely known among the people that the British surgeons view the coucher and all his methods with extreme disfavour. Patients are therefore reluctant to admit having consulted him, and they also are afraid lest treatment should be refused them, once their true history is known; for it is common knowledge amongst them that the Western practitioner is extremely reluctant to interfere with an eye which a coucher has spoilt. It is well, therefore, to consider carefully the grounds on which the physical diagnosis of a couched lens should rest.

We will first consider the case of those eyes in which the cataract has been definitely removed from the neighbourhood of the pupil. These present certain well-marked signs: (1) The pupil is brilliantly black, and (2) the plane of the iris is flat. It may seem strange to insist upon these points, but to the trained eye they are so obvious that a diagnosis can often be made, as soon as the patient takes his seat in the out-patient room, in front of the surgeon. The quality of the blackness of the pupil is difficult to put into words, but it arrests the attention by its contrast to the ordinary appearance of the pupil in people so advanced in life as the subjects of cataract usually are. The phenomenon is due to the whole cataract, capsule and all, being thrust away from the pupillary area, and it can be equally well seen in cases which have undergone the intra-capsular operation. Then, with regard to the flattening of the iris, the trained eye is used to the appearance presented by the slight forward convexity of that membrane as a result of the presence of the lens behind it; whereas the complete removal, not merely of the lens, but also of the support of the suspensory ligament, makes the iris flatten out in its own plane.

On close inspection we notice other signs. (3) The iris, deprived of the support of the lens, is often tremulous. This can best be observed if the patient is bidden to move his eye sharply in different directions. (4) Scars may be seen on the iris. These are the result of tears of the membrane during the operation. In some cases they are associated with an irregularity of the pupil, which may be extreme, or with a limitation or absence of pupillary movements. In other cases the immobility of the pupil, which may be absolute, is associated with (5) an atrophic condition of the inner free margin of the iris. Such a condition is only met with in very long-standing cases. Transillumination of the eye will sometimes show up the scars, or the atrophic condition just referred to, as light spaces against the rest of the dark background of the iris. (6) A careful study of the cornea, or of the sclera in its neighbourhood, will often reveal evidence of the wound made by the instrument during couching. In the cornea these take the form of small nebulæ or leucomata, lying just within the limbus, and usually in the temporal quadrant. In one case a persistent fistula was met with, as the result, presumably, of the bursting of a staphyloma along the original track of a septic wound. Scars in the sclera are much more difficult to distinguish, but they can sometimes be detected by the pigmentation which overlies them; such pigmentation may be due to the inclusion of uveal pigment in the track of the wound, as has been shown by our pathological specimens: but this is not the only possible explanation of the discoloration, for in dark-skinned races a certain amount of pigmentation is not uncommon after injuries of the conjunctiva. In one of the eyes we examined, there was a filtering scar over a fistula which had formed along the track of a scleral wound. (7) We come now to the leading feature in the diagnosis of these cases—viz., the recognition of the displaced cataract in its new position within the eye. In the rare event of a lens being dislocated into the anterior chamber and fixed there, its presence can be easily recognised. Again, in a large number of the cases which present themselves in the out-patient room, the cataract can be seen floating freely in the vitreous, and bobbing up and down with the movements of the eye. In the case of the milky Morgagnian cataracts, or of those cortico-nuclear cataracts which present a glistening and pearly-sectored appearance, it would be difficult even for a beginner to fail to see the lens, which usually lies at the lowest part of the eye. As the patient sits in front of the surgeon, the gleam of the white cataract can be caught each time he looks downward, even though a distance of two or three feet may separate him from the observer. In the case of darker cataracts, such as the pigmented nuclear ones, frequently met with in Indian practice, a closer examination is required.

The patient must be brought nearer to the observer, and facing a good source of illumination. The surgeon then focusses the light on the pupil by the aid of a lens, bidding the patient at the same time to look downward. If this fails, the patient is instructed to bend his head forward, holding the face horizontal; the surgeon then places one closed fist on the back of his head, and gives a number of sharp raps on it with his other fist; when this is done, it is often found that the lens has floated forward on to the pupil. If the patient’s head be now quietly raised, the lens can be seen dropping gently away from the pupil, which turns from white or brown (according to the nature of the cataract) to black as it does so. The experiment can be repeated again and again. Sometimes the lens falls away from the pupil so quickly that the surgeon must stoop down and look up at the eye in order to see it. If even after this test he fails to see the cataract, it is safe to assume that it is tied down in its new position by inflammatory adhesions excited by the septic matter introduced at the time of operation. Such adhesions may consist merely of delicate fibrils of exudate, which slightly increase the consistency of the vitreous body, and so to a small extent limit the excursions of the lens; or they may be represented by firm and highly organised fibrous tissue, which mats the lens in its new position, and which may be so strong that even a post-mortem dissection would fail to disengage the cataract from its adventitious position. This subject has been dealt with much more fully in the chapter on pathology. The dilatation of the pupil by a mydriatic will often make it quite easy to discover the whereabouts of the cataract, especially if a strong light, whether natural or artificial, is focussed on the eye by means of a lens. Natural light is preferable to artificial if possible, especially in a country like India, where powerful daylight can be counted on during a large part of the year. The advantage of the white light is especially marked when dealing with brown or dark-coloured cataracts. An examination with the ophthalmoscope or with a transilluminator may sometimes be of value, but in the class of cases we are now discussing, these are seldom of much use, if the examination just described fails to reveal the whereabouts of the cataract.

There remain a few points of interest which deserve mention. Though in the great majority of couched eyes the cataract lies in the lowest part of the globe, it may be found either to the inner or to the outer side, or even in the upper half of the eye. Sometimes it flaps backward and forward with the movements of the globe, swinging on a hinge, which evidently consists of the remaining fibres of the suspensory ligament, and which may be situate in any possible direction, though most often it lies below. It will be readily understood that if this hinge is situate below, or to the inner or outer sides, the lens will flap away from the pupil downward, or to the hinged side, as the case may be. It is not inconceivable that, in repeatedly doing so, it may inflict some measure of injury on the neighbouring part of the ciliary body and retina, and may thus excite a local inflammation which will tend in time to tie the cataract permanently in the new position towards which it flaps, away from the pupil. In the event of the hinge being in one of the three directions now under discussion, the cataract will tend to fall forward on to the pupil only when the patient stoops forward, so as to bring his face into the horizontal plane. When the hinge is situate above, the latter is one of the few positions of the face in which the pupil clears itself in ordinary cases; but one meets with instances in which, despite the hinge being above, the pupil remains clear except when the face is horizontal, the lens lying most of the time in the upper segment of the eye. There is another factor, and probably a more frequent one, than that of the local injury inflicted by the lens during its movement, which tends to tether it in situ. This is the increasing consistence of the vitreous, due to the deposit within it of inflammatory matter, a point which has already been alluded to.

Our next consideration is that of the cases in which the cataract still lies behind the pupil. It then seldom, if ever, is in absolutely normal position, and it very frequently is found to have been moved bodily downwards or to one side, or obliquely. Again, but more rarely, it may be tilted backward at an angle with the plane of its normal position. In a great number of cases the history will help one, and, even when the patient denies couching, he will very often admit to having had “medicine applied to his eye by a native practitioner.” Should no such evidence be forthcoming, there may still remain that of the lesions to the cornea, the sclera, or the iris, to which attention has already been directed in the previous section.

From these cases we pass on to consider those in which the lens cannot be seen at all, owing to the occlusion of the pupil. Here our difficulties are greater still, and, if the history fails us, we must fall back on a careful search for signs of wound scars in the cornea or sclera, or of tears in the iris. A point which is always suggestive is the existence of a cataract in the opposite eye. In such cases as these, the contents of the chamber may be found to consist of pus or of blood.

Our next group is a still more difficult one, for in it no fundus reflex can be obtained. It embraces a number of conditions which may be shortly dealt with in turn: (1) Those in which the vitreous body has been converted into a more or less highly organised inflammatory exudate, which is impenetrable to the light of the ophthalmoscope. (2) Those in which this vitreous exudate has contracted inflammatory adhesions to the retina, and by its shrinkage has determined the total detachment of that membrane. (3) Those in which the vitreous chamber has become filled with blood. It is obvious that in all such cases our main dependence must be upon the history, though the other indications already outlined may help us in some of them.

Lastly there are the cases in which the eye is undergoing shrinkage, and those in which phthisis bulbi is following panophthalmitis. The history of the signs and symptoms of severe iridocyclitis or of suppuration will, in India at least, always excite a suspicion of couching having been performed, unless the patient has a definite story to tell of some other form of injury. Strangely enough, the inventive faculty of the Indian patient does not rise to the height of vamping a narrative of the kind. If he has had an injury, he tells of it readily. If he has been couched, he stolidly denies that anything occurred to cause his trouble, which he states “simply came of itself.”

It will be observed that in the preceding remarks we have dealt with two of the problems which confront us in diagnosis, for the simple reason that it is very difficult to separate them; to do so would mean needless repetition. The discovery of the new position of the lens, and of the degree of fixation, if any, it has undergone, can hardly be divorced from the question of whether a couching has or has not been performed. Our third problem was to decide whether it is advisable to operate in any cases, and if so, in which. The Baron de Wenzel, in his treatise on cataract,[4] records two cases in which his father successfully extracted couched lenses. A number of Anglo-Indian surgeons have had similar experiences, but most of them are reluctant to interfere with these cases oftener than they can help, because, should the operation fail, it is extremely likely that they will unjustly incur the odium for the loss of the patient’s vision. On this subject Maynard wrote (Ophthalmic Review, April, 1903): “It may be justifiable to attempt the removal of a recently couched lens. If not recent, and more especially if the lens is fixed, it is wiser to leave it alone, even if the sight is failing.” To the writer’s mind, the one crying indication for removal of a couched lens is that it flaps across and obstructs the pupil. He agrees strongly with Maynard, that if the lens is fixed it is better left alone; but he is doubtful whether the time element is of very great importance, in comparison with the mobility of the cataract; for a study of the fifty-four globes already dealt with has shown him that the fixation or otherwise of the lens is a question of the amount of septic action set up by the operation. If this is small, the lens may continue mobile, even for a very long period; if it is more severe, the latter will soon be tethered. Dealing with this subject five years ago (Proc. of S. Indian Branch of B.M.A., March 13, 1912), the author wrote as follows:

“We are extremely reluctant in Madras to undertake further operative procedures on an eye in which couching has been performed. Removal of a lens dislocated into the posterior chamber obviously means a wide opening up of the vitreous; and even if the immediate result appears good, there is little guarantee that the benefit will continue. Of eighteen cases in which the lens was removed, twelve obtained better vision at the time, four remained in statu quo, and two were rendered worse. I cannot but think that these statistics would suffer if the cases were followed for some years. On five occasions we undertook the laceration of an after-cataract which blocked the line of sight after couching. In two cases there was considerable benefit, whilst in three vision remained in statu quo ante. In four cases an iridectomy was performed for optical purposes. In two vision improved slightly, whilst in the two others it remained as before.

“Personally I have a strong and growing objection to undertake any operative procedure on a couched eye. Firstly, there is the risk of lighting up a septic explosion, for which the real responsibility lies with the coucher’s original operation; and, secondly, there is the danger of being saddled with the discredit which is justly due to another man’s failure.”

Reviewing these paragraphs in the light of the much better knowledge of the pathology of couching which we possess to-day, he would urge that only freely movable cataracts should be touched, since want of mobility is associated with profound changes in the vitreous due to septic action. The object that a surgeon sets before him, work where he may, is ever the same—“The greatest good of the greatest number.” Failure in such cases as these may play into the hands of the coucher, and enable him to extend his sphere of influence at the expense of the beneficent work of the Western hospitals. The problem in India is a difficult one, in which surgical considerations do not stand alone, but are interwoven with social, moral, and even political questions. Each surgeon must decide for himself what line he will take, and follow it fearlessly.

In this connection, Major Kirkpatrick’s experience[5] in Madras is of considerable value, for he has removed a number of couched lenses, and has been “struck by the rarity of vitreous escape, even after fairly extensive investigation with a spoon,” during this operation. He adds: “I have noticed that the vitreous body becomes shrunken and extraordinarily tough, so much so that, when an eye is excised (either for glaucoma or for iridocyclitis following Mahomedan operation), the whole globe can be held up by a strabismus hook transfixing the vitreous, though the latter appears perfectly clear. The vitreous undoubtedly does undergo shrinkage, and leaves a large space, which is occupied by aqueous.” It is plain that he is referring here to cases in which the vitreous body has undergone some measure of inflammatory organisation, which might be expected to limit the mobility of the lens, and it will be of great interest to learn whether the conclusions of so reliable and experienced an observer ultimately coincide with the author’s, that interference should be confined to those cases in which the movements of the cataract within the vitreous body are noted to be free. Once again, let it be emphasised that there are two distinct questions at issue—one the benefit of the individual patient, and the other the good name of Western surgery. Each man must be guided according to the dictates of his own personality and of his environment.

CHAPTER VII
CLINICAL

There are, in connection with cases of couched cataract, some points of clinical interest which will repay closer attention. These will now be dealt with in turn.

Pain.—The pain which follows the operation of couching has attracted the attention of surgeons from very early times, and there has been much speculation as to its cause. When, after Daviel’s discovery, extraction came into serious competition with the older operation, surgeons discussed at much length the relative merit of the two procedures, and it was strongly urged by the extractionists that their operation gave rise to less pain than that of couching. The subject is a very difficult one, for no surgeon, who has had a large cataract practice, can fail to have been struck by the extraordinary difference in the statements of patients as to the amount of suffering they have endured during the first twenty-four hours after the removal of a lens. The majority of them confess to a good deal of pain; this comes on as the effect of the anæsthetic wears off, reaches a maximum, and then slowly dies away, leaving them at the end of twelve hours, and often even at the end of six hours, comparatively comfortable. Occasionally, but rarely, the report is that the pain has been negligible throughout. On the other hand, a bitter complaint of very severe pain is sometimes encountered; fortunately such an occurrence is infrequent. In the case sheets on which the writer’s 780 cases were taken, a special heading was provided for notes on the pain inflicted at or after operation. A striking feature of the replies given was the extraordinary difference between them; this is the more astonishing because in a large number of the operations it is probable that no anæsthetic of any kind was used, and yet it was by no means uncommon to meet with patients, who made little or nothing of the pain either at the operation or after it. On the other hand, some complained of terrible suffering, commencing as soon as the needle was inserted, and lasting for long periods thereafter. The majority admitted to some pain, but neither belittled nor exaggerated it. It will thus be seen that, so far as pain is concerned, the experiences of the coucher and of the extractor are much alike; it is unfair to judge either operation on exceptional cases.

Looking at the subject from the anatomical side, the writer is bound to confess that an argument a priori would have led him to expect extraction to have been by far the more painful of the two procedures, both at the time and during the early hours of convalescence, although much has been made by early writers of injury to the retina and to the sensitive ciliary body, and of the extensive damage done by the needle during a couching. We know, however, that injury to the retina does not produce pain; and we are also well aware of the extreme susceptibility of the cornea to pain. Surely the extent of damage inflicted on sensitive structures is, as a rule, much greater in an extraction than it is in a couching. How then are we to explain the dread with which surgeons, in the days of couching, looked forward to the suffering and vomiting which sometimes followed the operation? In answer to this question the following suggestions are put forward. The pain of the first twelve hours is to be sharply differentiated from that which begins on the second or third day, always remembering, however, that, though the causes are different, the one may run into the other. The early pain may be ascribed (1) to injury to the nerves of the ciliary body and iris, especially when the laceration of those structures is considerable, as our clinical experience and our specimens alike show it sometimes is; (2) to hæmorrhage from the vessels of the ciliary body, the iris, the choroid or the retina: such hæmorrhage may produce pain in two ways—(a) by dissecting up sensitive structures, and (b) by increasing the tension of the eye; and (3) to the rapid production of early glaucoma. There are several ways in which we may conceive that such a glaucoma might be produced. We have already mentioned the possibility of hæmorrhage. Then we have to remember that, in the course of this operation, the anterior portion of the vitreous body is often extensively interfered with. It is conceivable that a forward movement of this part may close the angle of the chamber, and so interfere with excretion. Again, when the lens is forced back on the vitreous body, and the anterior hyaloid layer remains unbroken, we sometimes find it acting as a wedge, pushing the base of the iris forward, and thrusting the hyaloid membrane backward. The latter action must press on the vitreous body, and so make it bulge at other parts of the circumference of the eye, thus tending to close the angle of filtration over such areas. It is obvious that the pressure of the lens on the iris base will directly close the sinus locally to a greater or less degree. A point that we must never lose sight of is that the very great majority of these patients are in the glaucoma period of life, and with a certain number of them very little alteration of the status quo is required to precipitate an attack of pathological high tension. If we take all these factors into account, and especially if we bear in mind the great variability that different patients present in their sensibility to pain, we shall have little difficulty in understanding that couching may sometimes be followed within the first few hours by great suffering attended with vomiting.

When we come to discuss the later pain, all difficulty vanishes. The frequency with which iridocyclitis and glaucoma dog the footsteps of couching in India, explains at once the bitter and oft-repeated history of pain coming on within the first two or three days, and lasting for months or even for years.

Some Rare Accidents following Couching.—In a large series of cases such as we now have under review, it was to be expected that some unusual incidents would be met with. A few of these will be dealt with.

1. The Dislocation of the Lens into the Anterior Chamber.—This accident was known to the early writers. It may occur either at the time of operation or subsequently. In the former case the nucleus alone may be dislocated, or the whole lens may be driven forward in its capsule. It may lie loose and freely movable in the chamber, or may become mechanically impacted there, or, lastly, may be firmly fixed in situ as a result of inflammatory action. In the cases of late dislocation it is usually the nucleus alone that passes forward, the cortex having either become absorbed or the cataract having originally been of the Morgagnian variety. Such are the cases which give rise to the interesting clinical phenomenon of a nucleus which passes backwards and forwards between the two chambers. In some cases alterations in the position of the patient’s head suffice to make the lens travel in one direction or the other.

2. The Dislocation of the Lens between the Ciliary Body and the Sclera through the ruptured pectinate ligament occurred in one case. Such an accident must be very rare under any possible conditions of eye injury. J. B. Lawford, in the Reports of the Royal London Ophthalmic Hospital (1886–87, p. 334), recorded a similar happening which followed a blow on the eye by a clasp-knife thrown at a woman. Nettleship (Ophth. Soc. Trans., vol. i.) also published a case in which an opaque lens disappeared into a pouch between the choroid and sclera when the patient lay down, and reappeared in the anterior chamber when he stood up. The condition followed a blow on the eye inflicted some years previously.

3. Dislocation of the Lens behind the Retina.—This accident was known to the early writers, and Mackenzie expressly gives the warning that, if in effecting depression “the handle of the needle is raised much higher than the horizontal position, the cataract is apt to be pressed through the retina, and vision extinguished.” Daviel had met with the same condition in eyes which he dissected after death, and which had been couched by other surgeons. We, too, encountered it twice in our pathological material. In one eye the retina had been torn away from the ora serrata, and the lens pushed behind it; in the other, an extensive hole had been torn in the retina, and through this the cataract had been thrust. In both, the cataracts were Morgagnian and had been dislocated in their capsules, and in both, the retinæ had undergone total detachment, in this latter respect testifying to the value of Mackenzie’s warning.

A Comparison of Depression and Reclination.—There can be no question that the operation of reclination breaks up the vitreous body to a considerably greater extent than mere depression of the cataract does. On the other hand, the claim is made that after its performance the lens is much less likely to undergo reascension; indeed, it was for this reason that Willburg introduced the method; and, if we may judge from the evidence of later writers, he was justified by results. So far as the Indian coucher is concerned, it seems a little doubtful whether he has any clear conception of the difference between the two procedures; indeed, so long as he gets the lens out of the way of the pupil, it is probable that he neither knows nor cares which method he has succeeded in adopting, though he probably much more often reclines than depresses. This may be explained by the experience of a number of European surgeons, that it is more easy to effect reclination than depression. An interesting point is that in quite a number of our pathological specimens the lens lay in front of the anterior hyaloid membrane, and therefore outside the vitreous body; most of these were cases of depression, but in a few of them the lens is turned backwards at an angle with its ordinary plane, clearly showing that a partial reclination had been effected.

Reascension of Couched Cataract.—This subject has been partly dealt with in the preceding paragraphs. Naturally, it was a topic which attracted a good deal of attention from the early writers, who commented on its relative frequency immediately after the operation, and gave elaborate instructions to prevent its occurrence. Some of them went so far as to suggest the frequent repetition of the operation, if necessary. In their experience it would appear that, if reascension failed to occur within the first fortnight, the prospect of the lens remaining down was good. Nevertheless, they were familiar with the fact that, even after years of a happy result, the cataract might suddenly be found to have returned to its old position opposite the pupil. In some cases this misfortune followed a blow or fall on the head, or a severe jar of the whole body. Similar stories may be heard in an Indian out-patient room to-day. This is a point which must be taken well into consideration by any who think fit to resort to couching in selected cases.

A Comparison of the Corneal and Scleral Routes for Operation.—It has been already shown that the Indian operators of the present day vary in their technique, some attacking the lens from in front through the cornea, and others from behind through the sclera. It is interesting to note that there is a similar difference in practice amongst those of the modern surgeons who have adopted couching in special cases. There can, however, be no doubt that the weight of opinion among the old writers was all in favour of the posterior operation; and Mackenzie, whose practical experience was, we may hope, vastly greater than that of any modern surgeon, summed up the position in these words: “In this way (i.e., through the cornea) neither operation (depression or reclination) can be satisfactorily performed.” We may close this subject with another word of warning to any who are inclined to favour the couching of lenses in selected cases. From the time of Celsus onwards, surgeons who have had large experience in couching have warned their disciples that it is an operation much more easy to undertake than to carry to a successful technical issue, and have cautioned them against venturing on it until they have seen it performed many times at the hands of an expert. One cannot conclude better than by a quotation from the writings of Lieut.-Colonel Henry Smith, who has had very large opportunities of observing the results of cataract couching. He is known to be a very skilful operator, and one, therefore, who is little likely to exaggerate the difficulties of any ophthalmic procedure, yet he writes: “It is no easy matter to completely dislocate the lens, and, in my observation, the partial dislocation is more frequent than the complete in the hands of adepts of the art.”

The Dislocation of Morgagnian Cataracts.—A curious error is to be found pervading many of the early writings on couching—viz., that a Morgagnian cataract could not be couched in its capsule. Our hospital experience in India proved that this idea was erroneous, and the examination of our pathological specimens has shown the correctness of our clinical deductions. The Morgagnian lens may be dislocated forward into the anterior chamber, backward into the vitreous, and even through the coats of the retina, without rupture of its capsule. This is far from being a surprise to any surgeon who has operated on a number of these cases, for the Morgagnian capsule is usually very much tougher than that of any other form of cataract. It has already been mentioned that, if the capsule bursts, the nucleus may escape, and may then sometimes be found either floating freely in one of the chambers of the eye, or fixed in one position by inflammatory adhesions, or, still more rarely, passing from chamber to chamber at intervals. The writer has observed that in some cases the escape of Morgagnian fluid into an eye appears to cause great irritation. The same fact has been observed by some of the early writers on couching.