The Indian operation of couching for cataract

by Robert Henry Elliot

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.