Cataract extraction / by H. Herbert.

  • Herbert, H.
Date:
1908
Catalogue details

Licence: In copyright

Credit: Cataract extraction / by H. Herbert. Source: Wellcome Collection.

Provider: This material has been provided by UCL Library Services. The original may be consulted at UCL (University College London)

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    the two methods in equal numbers of cases from his own practice, 293 of each operation, gave percentages of 1*02 and 5-8 vitreous losses. Marshall's Moorfields figures' from 1889-93, showed only a small difference—2-99 per cent, and 375 per cent. The risk of prolapse of iris renders simple extraction seldom applicable for private work in a patient's house unless one is prepared to visit the case next day with an assistant, prepared to excise iris, if necessary. On this account I have scarcely ever adopted the method in private operations. (Czermak's sub- conjunctival operation is almost free from this objection.) The Selection of Cases.—The cataract must be ripe, or its removal will be incomplete. It must not be very overripe,! with opaque capsule to be extracted.:;: And tremulous and subluxated lenses, also cataracts in eyes with presumptive (in high myopia) or certain disease of vitreous, all demanding the easiest possible delivery of the lens, are excluded. Also usually ' black ' cataracts—hyper- sclerotic lenses—too large to pass easily through the pupil. (In general, the older the patient the more often may iridectomy be needed on account of the large size of the lens.) An iridectomy may be necessitated by a small and rigid pupil,§ or, for optical reasons, by central corneal opacity. For both optical and mechanical reasons by synechiae, anterior or posterior, it being necessary to provide space ^ R. L. O. H. Rep., xiv, 56. t Morgagnian cataracts, though overripe, arc very suitable for simple extraction if they happen to possess transparent or nearly transparent capsules, as they not infrequently do. X The Punjab operators, Mulroney and Smith, extracted lenses in their capsules without iridectomy. But Smith now performs these operations preferably with iridectomy. § The rigidity of pupil may have been noticed by very imperfect dilatation in the dark room, and later under the influence of cocain. Otherwise it may not be noticed till an attempt is made to expel the lens, when it may be one of the troubles which transform an intended simple extraction into a combined one.