Imatges de pÓgina
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While any portion of the capsule preserves its connection, it continues to be nourished, and of course, resists absorption; but an insulated portion of capsule is dissolved and absorbed, like any

other matter extraneous to the circulation. These facts are ascertained by the aperture in the capsule remaining ever after unchanged in dimension, and if it be equal to the natural aperture of the iris, so that its broken margin cannot be seen in the pupil, it will always appear upon dilating the pupil with the belladonna. If the aperture be made of a given size and figure, as for example, the figure of a small diamond, in the centre of the capsule, it will ever after retain its figure and dimensions. But where the aperture is ultimately of the full size of the pupil, it is evident that the portion of capsule that has disappeared, must have undergone solution and absorption with the lens. The transparent capsule is tense and contractile as well as delicate in texture, so that a wound made in it is enlarged by the retraction of its sides; but the retraction without loss of substance would be very insufficient to account for the magnitude of the aperture, and we continually see that a mere puncture or cut of the transparent capsule, from accidents with pins and scissars, unites by adhesion, forming an opacity. In the opake capsule, which has no contractility, it is still more decidedly proved, that the aperture of the size of the pupil must be produced by the laceration of the capsule in fragments, and the absorption of these fragments together with those of the lens.

The reasons why the operation of Mr. Saunders is objectionable in the two latter species of cataract are, first, the degree of force required to break down these cataracts with the needle, sufficiently to undergo a quick solution in the aqueous fluid; and secondly, the danger of dislocating the lens in the attempt. If the operation upon a cataract of firm consistence is conducted with the caution which experience dictates, the process of solution is tediously slow, and the operation must factory explanation than has yet been offered, as the familiar case of a cata. ract formed by the wound, and undergoing absorption.

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be repeated many times; but this is the least evil. If the operator, after having opened the capsule in the centre, acts with the same freedom as upon the soft species of cataract, the unsupported lens falls forward, or revolves and turns edge foremost in the pupil, so as to put the iris on the stretch; or it passes entire into the anterior chamber. If he succeed in di. viding it, large and solid masses will press upon the iris, wedge in the pupil, or pass into the anterior chamber, and the consequences be the same in kind though less in degree. Even where the operation is confined to the aperture of the capsule, and the lens has been scarcely touched, I have known the eye destroyed by the accidental falling of the lens through the aperture and pupil into the anterior chamber; a slow inflammation of the iris ensues, which not only produces the most distressing symptoms, but admits of little, if any alleviation, until the mechanical pressure is taken off. This event, so much to be desired, is unfortunately protracted, for the process of solution is arrested by an adventitious coating of lymph, which is effused by the inflamed vessels, and invests the extraneous body. This lymph becomes partially organized, and the case terminates in obliteration of the pupil and anterior chamber, or by the sympathy of the retina with the suffering iris and choroid, in incurable amaurosis. Having more than once observed the protrusion of the lens, and the consequent inflammation of the iris to ensue, where I had studiously endeavoured to prevent it, I was led to suppose this might be owing to the previous dilatation of the pupil by belladonna, by which the lens was deprived of support. I therefore omitted the previous use of the belladonna where the cataract was substantial and firm. It was then applied to the eyebrow an hour or two after the operation, with a view of preventing the adhesion of the pupil to the capsule of the lens; but under the influence of the belladonna, I repeatedly observed, that the unsupported

I lens came forward, and the symptoms of pressure commenced. I therefore deferred its employment until a time sufficient had elapsed for the renewal of the aqueous humour, which, I con

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ceived, might resist the pressure of the lens. By this precaution the accident was effectually prevented, no symptom of inflammation followed, and the advantage of keeping the pupil circular was equally obtained. It may be right to observe here, that when the belladonna is used with this view, the interval of its application should be sufficient to admit of the recovery of the pupil, or it will be permanently dilated. With every precaution, however, the operation with the needle upon the full and firm cataract, is either distressingly tedious, or what is more to be objected to, destructive to the organ, and very

, trying to the health and spirits of the patient. In such cases I have, therefore, relinquished the operation, which was very ingeniously conceived, and for its simplicity appeared to me to deserve a full and fair trial of its merits. It is due to the projector of the operation to state, that its superiority was distinctly asserted by him only in the cases of soft and capsular cataract, as may be seen by a reference to his essay ou that subject, in his posthumous work edited by Dr. Farre. At page 173 of the volume referred to, the editor observes, “ In the adult, if the texture of the lens is nearly uniform and permeable, the cure is completed in a space of from three to five months; but if the texture is firmer and the nucleus large, the cure cannot be accomplished in less than seven months. On this account the author, who thought highly of extraction, and performed this operation with dexterity and success, was ioclined to extract the lens when its texture was unusually hard. The editor cannot assert that he would ultimately have conceded thus much in favour of extraction. It was intended that such decision should result from a very long and impartial trial of both operations. With respect to the softer lens, or the capsular cataract, he was satisfied of the superiority of his operation."

In performing this operation for the soft cataract the operator may pass his needle through the cornea or the sclerotic. The former mode commands the advantage of giving no pain, exciting but slight inflammation, and ensures the laceration of

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the transparent capsule, which is sometimes so elastic that the operator, whose eye is not well accustomed, is in danger of not opening it in the centre, or of wounding the interior surface of the cornea. This is especially to be feared in operating behind the iris, when the lens is, at the same time, much dimi. nished by absorption, as in children; so that the capsule moves before the needle instead of resisting it. Few cases of lenticular cataract occur, to which this method is appropriate, and in which it is adviseable to perform the posterior operation. There is more pain, more inflammation, more danger of displacing the lens than in the operation through the cornea. But when the capsule is opake and the lens diminished in bulk, either spontaneously or in consequence of former operations, so as to have receded from the pupil, the posterior operation is more eligible, as the operator readily ascertains the effect of the needle upon the capsule, and directs its movements to the best advantage; while the inflammation is always moderate in proportion as the lens is small. Indeed, in the purely capsular cataract of the adult, and the half absorbed cataract of children, it is so slight as scarcely to confine the patient. When a cataract of firm consistence has undergone a partial absorption from one or more operations with the needle, and still does not readily separate into fragments, the introduction of the needle, posterior to the iris, gives the surgeon the advantage of couching it. This I have often done, to the great satisfaction of the patient, who escapes, owing to the diminished bulk of the lens, the inflammation which occasionally follows the primary operation of couching. It was my intention to point out the circumstances which should determine the election of couching or extraction in the two latter species of cataract, and to shew the value of these operations relatively to each other and to that by solution, as the deliberate result of an impartial investigation of all. This I shall make the subject of a future communication.

SELECTED REVIEWS.

Practical Observations on the Treatment of the Diseases of the

Prostate Gland. Illustrated by Copper-Plates. By EDWARD HOME, Esq. F. R. S. Serjeant Surgeon to the King, and Surgeon to St. George's Hospital. 8vo. pp. 360. London, Nicol, 1811.

[From the London Medical Review, for January, 1812. ] The frequency and importance of diseases of the urinary passages, the insufficiency of the means employed for their core, and the unchecked course which many of them hold to a fatal termination, have rendered them at all times subjects of much interest. But it is not until comparatively recent times that any thing very material has been added to our knowledge of them, or much improvement introduced into the mode of treatment. A subject which has engaged the par• ticular attention of such men as Hunter and Desault, cannot but have been illustrated by their researches. In this country Mr. Hunter was perhaps the first who led the way to a more scientific mode of treating many of those disorders, by his valuable observations in his Treatise on the Venereal Disease. In France the subject has been taken up by Desault, who appears to have prosecuted his inquiries with the same ardour that characterised all his labours for the improvement of surgery. Of the surgeons of the present day, there is no one to whom we are more indebted for an extension of our knowledge of diseases of the urinary passages than to the author of the work before us. Mr. Home has had the advantage of a very ample experience, and it has evidently been with him a subject of particular study.

The first part of this volume consists of a republication of a paper read before the Royal Society, and thought worthy of being published in their Trausactions. It contains an ac

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