Of the five cases shown under vitreous opacities, three were obviously due to the inflammation of the uveal tract posterior to the iris; two others were due to hæmorrhage into the vitreous. Many more cases would undoubtedly have shown vitreous opacities had the pupils been patent. Moreover, our pathological data show that not a few of the cases in which the fundus reflex was absent presented dense exudates into the vitreous cavity. This subject will be dealt with at length under pathology. The genesis of hæmorrhage into the vitreous is obvious, and it is more than probable that if all the cases were seen at an early stage the figure for this complication would be much higher.
From the foregoing notes, it is clear that the native coucher undertakes a certain number of what we should recognise as inoperable cases. It is possible that in many of them a secondary cataract is present; but it is clear that his diagnostic powers are low. He is a standing menace to the safety of the public.
It has from time to time been suggested that the presence of the lens in the vitreous chamber brings about retinal changes. The author is not, however, aware of any reliable evidence either ophthalmoscopic or pathological to support this view. As far as possible, all cases seen in Madras were submitted to ophthalmoscopic examination, whether the couching had resulted in success or failure. We were unable to discover any characteristic change which could be attributed to the couching. A large percentage of the fundi examined appeared to be absolutely normal. The most frequent departure from normal was an undue distinctness of the choroidal vessels, which was evidently due to the absorption of the pigment of the pigmentary layer of the retina. It is probably this phenomenon which has misled some into the belief that couching is followed by changes in the retina allied to those in retinitis pigmentosa sine pigmento. This absorption of retinal pigment is, however, well known to occur in other conditions, as, for instance, in high myopia; moreover, in the case of couched eyes, it is not accompanied by the changes in the disc and vessels characteristic of retinitis pigmentosa, or by the equally characteristic night blindness. In searching for the explanation of this phenomenon, four solutions at once present themselves for consideration: (1) It might be, as has been suggested, a result of couching; (2) it might be due to the alterations in the refractive conditions under which the fundus is seen; (3) it might be a physiological abnormality; and (4) it might be an accompaniment of, and a direct result of pathological changes in the eye accompanying the development of cataract. The third suggestion is thrown out by our experience of normal native eyes. An important light has been thrown on the whole question by the observation that a similar change is found in quite a number of eyes which have been submitted to cataract extraction. This disposes of the first idea, that the presence of the lens in the vitreous would account for the phenomenon. Neither experience nor theory support the view that an alteration in refraction is responsible for the appearance. We are thus narrowed down to the conclusion that the pigmentary change is an accompaniment of the development of cataract in a certain percentage of eyes, and is independent of the method of operation resorted to for the relief of that condition.
In this connection, two interesting observations deserve record, as they possibly throw an important sidelight on the question at issue: (1) Lenses extracted in India differ from those met with in European practice, in the amount of colouring matter they contain. A very large percentage of them are stained with pigment, which is frequently of a deep tint. Many of them are dark brown, and a few are almost black. (2) Cyanopsia is of extraordinarily frequent occurrence as a sequela during convalescence after cataract extraction in Madras. Over 50 per cent. of the patients complain of it, whilst only 2·8 per cent. suffer from erythropsia, and 1·2 per cent. from yellow or green vision.
We thus find two very striking differences between Western and Eastern cataract experience, and there is, to say the least of it, a strong suggestion that the phenomena are closely connected with each other—in other words, that the cyanopsia is a result of the retina becoming tired out for the perception of yellow by long exposure to a tropical light filtering through a brown or yellow lens. There is also a strong presumption that the coloration of the lenses is due to a migration of pigment, which takes place during the development of cataract in the East, a migration which is directed from the pigmentary layer of the retina, and probably from other parts as well, towards and into the developing cataracts. If the above hypothesis is correct, we might assume that the retina is more likely to be functionally affected in an adverse sense when deprived of the protection ordinarily afforded by its pigmentary layer. In order to test this, the author some years ago made a systematic examination of a large number of eyes from which cataracts had recently been removed, with the object of ascertaining whether cyanopsia was complained of, principally or only, in those cases in which the choroidal vessels were seen to stand out with unusual distinctness under ophthalmoscopic examination. The depth of discoloration of the lenses was at the same time noted in each case. The results obtained appear to favour the views we have above enunciated, but they were not sufficiently conclusive to justify the formation of a decisive opinion. It must be remembered that, whilst a tinge of colour runs through most of the cataractous lenses removed in the East, there are very wide variations, not only in the depth of the pigmentation, but also in the actual coloration present. Some of them are yellow, some reddish-brown, some almost coal black, with every intermediate shade between. It is possible that our investigations failed for want of competent assistance with the spectroscopic analysis of the lenses. An interesting field for research is here presented. That deep-seated metabolic changes accompany the development of a cataract has been shown by J. Burdon Cooper, and it seems not unlikely that the apparent prevalence of lenticular opacities in tropical countries may be closely bound up with the metabolic changes we have described. It is probable that the retinal pigment layer is not the only source of the deep discoloration of the lenses met with by surgeons in India. A point in favour of the argument we have been elaborating is that some years ago McHardy published the analysis by MacMunn of the spectrum of the pigment obtained from a black cataract. This was found to be quite distinct from blood-pigment, and to be allied to the cell-pigment, which gives coloration to ectodermal structures in animals (Trans. of the O.S. of the U.K., 1882).
To collect the 780 cases now under review has taken over twelve years, and the writer is deeply indebted to Major Kirkpatrick for his great generosity in allowing his 230 cases, the later ones of the series, to be made use of in this paper. Throughout all these years one definite purpose has been kept in the forefront—viz., to ascertain the real value of lens couching. After making every possible allowance for the vaidyan, the fact remains that he is a standing menace to society, and that he should be suppressed. His methods are crude, filthy, and dangerous; his results are so appalling that anyone unacquainted with the ignorance and credulity of the Indian ryot would think it impossible for him to continue to exist. His impudent lying includes not merely a grossly exaggerated statement of his own successes, but extends to the most barefaced falsehoods as to the nature of the results obtained in European hospitals. It may be permissible to quote one instance—unfortunately, far from a solitary one in Madras experience. Some years ago a peasant, who had had a cataract removed in the Government Ophthalmic Hospital, and whose recollections of his treatment there were most kindly, returned for operation on the second eye. On the steps of a temple, within a hundred yards from our operating theatre, this man, who had travelled several hundred miles for aid, was induced, by a tissue of impudent lies, to sit down and submit to couching. A few days later he presented himself at the out-patient room with panophthalmitis. There is no branch of ophthalmic disease and treatment in India which so profoundly impresses the Western surgeon’s imagination as this one. Remember that cataract strikes a man down in his maturity, at a period of his life when he has begun to reap the benefits of his earlier years of toilsome industry. His pay and his home expenses are both alike at their maximum. He is treading the higher rungs of the official or business ladder, and is endeavouring to afford his children the best education in his power. Few pictures are more pitiful than that of such a man passing hopefully down an avenue of credulity and ignorance to a fate to which death itself is often preferred, the horror of a great and lifelong darkness. On the other hand, Government, the protector of the poor, stands by powerless to interfere, and supinely watches this catastrophic waste of human energy. The cords that bind the individuals are woven a million-fold together to tie the hands of the rulers more securely still. Every civilized nation of to-day recognises it as a first principle, that it is its duty to protect its people from avoidable harm, and that to deal with preventable blindness is one of its primary duties. That men and women, who ought to be burden-bearers, should be thrown instead as a burden on their relatives or on the State, is a social evil of no small magnitude. One does not presume to blame either the State or the people. It would obviously be idle and wrong to do so. The plain indication is to arouse the medical conscience of the country, to start men thinking of the evils which are so rife in the land; and so to introduce a ferment, as it were, into the medical mind of India, and then to leave it to do its work. It is not suggested that the country is ripe for legislation on the subject. The people are not ready for it. There are, however, two distinct avenues along which an advance may safely be made—viz., (1) the systematic dissemination of knowledge through Government agencies amongst the people; (2) the improvement of ophthalmic medical education. A movement in these two directions is already on foot, and in time it will bear much fruit.
CHAPTER V
THE PATHOLOGICAL ANATOMY OF COUCHED EYES
Being the Hunterian Lectures delivered before the
Royal College of Surgeons of England on
February 19 and 21, 1917
The material at our disposal consists of 54 globes, the great majority of which were removed in the Madras Ophthalmic Hospital in the period from 1911 to 1915, though some are of much older date. They were placed in 5 per cent. formalin immediately on removal, and were subsequently frozen and bisected. In a number of instances one half of the eye was submitted to microscopic examination after suitable sectioning. Each of the half-globes and a number of microscopic specimens have been photographed for purposes of illustration. It will be convenient to classify our observations under a number of separate headings.