VOL. LII.] PHILOSOPHICAL TRANSACTIONS. 625 



LXXXIL On the Success of Mons. Daviefs Method of Extracting Cataracts. 

 By Andrew Cantwell, M. D. p. SIQ. 



The extraction of the crystalline from the posterior chamber, by an incision 

 made in the cornea, with a design to cure the cataract, seems to have been first 

 attempted by Mr. Daviel. It is true, surgeon Petit, and the oculist St. Ives, 

 extracted it out of the anterior chamber in 1708, and the following years; but 

 that operation was designed only to rid this chamber of an accidental burden 

 fallen into it, in couching the cataract; and it is very reasonable to believe it was 

 only the examples of these 2 operators that led Daviel into this new method, 

 which has wonderfully facilitated the cure of that disorder, and cleared up the 

 many difficulties that appeared in it. 



The Greeks and Arabians considered the glaucoma as an incurable cataract ; 

 and the moderns pretended that the incurability proceeded from the nature of 

 some other distemper complicated with the cataract. It was hard to tell why, 

 the cataract once couched, the patient should remain blind, or why it should rise 

 again into its place. 



This new operation shows that not only the crystalline, but even sometimes 

 its capsula, and sometimes only the anterior membrane of this bag, are opaque, 

 sometimes adherent to, sometimes separated from, the body of the crystalline. 

 Sometimes the anterior membrane of this bag has been found opaque, and the 

 crystalline transparent, and in all these cases the patients have recovered their 

 sight. 



With this account Dr. C. sent a small box, in which were 3 packets. N° 1 

 contained a portion of the anterior membrane of the capsula crystallini. This 

 humour, being still transparent, was left untouched. The patient saw perfectly 

 well after the operation. N° 1 contained an opaque crystalline, and a portion 

 of the anterior side of its bag, quite opaque. The patient recovered his sight. 

 N° 3 contained the whole bag and crystalline, extracted the 14th of this month. 

 It adhered to the posterior and superior side of the iris ; and was quite whole and 

 plump when drawn out. In this last case it commonly happens that some portion 

 of the vitreous humour follows; sometimes it mixes with the aqueous, and comes 

 off with it; sometimes the eye appears quite sunk; and sometimes the vitreous 

 humour filling as it were the posterior chamber, makes the iris bulge forwards, 

 and appear prominent on it, the whole together resembles a kind of hernia. 

 These two last cases require a nice and pnident hand: the prominent vitreous 

 humour is to be cut off in "2 or 3 days after the operation, the eye then banded, 

 but not compressed, and the patient laid in his bed, the head lower than usual, 

 till the rest of the vitreous humour gets back into its cells, and remains thereV 

 This he had seen examples of; the vitreous humour regenerates, and though a 



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