The principles and practice of ophthalmic medicine and surgery / by T. Wharton Jones.

  • Jones, Thomas Wharton, 1808-1891.
Date:
1847
Catalogue details

Licence: Public Domain Mark

Credit: The principles and practice of ophthalmic medicine and surgery / by T. Wharton Jones. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    has not taken place, and cannot be made to do so by gentle pressure, the operator carefully introduces the blunt hook, and catching the iris by its pupillary margin, draws it out and snips it off. If the forceps is used for drawing out the iris, it must be made to lay hold of it very cautiously at a little distance from the pupillary margin—close to the junction of the larger with the smaller circle of the iris. 1548. The size of the new pupil should be at least equal to that of the natural pupil in its middle state. As to the quantity of iris to be cut off, in order to obtain a pew pupil of this size, it is to be remembered that if the structure of the iris is healthy, even when but a small piece is snipt off, the aperture which results will be of considerable size. 1549. What of the iris may remain protruding is to be gently pressed back with the curette. The eyelids are then to be closed, rubbed over the cornea, and suddenly opened to the light. Central excision. 1550. As performed by Wenzel, this consisted, 1st, in mak- ing a half section of the cornea as for extraction, with the addi- tional manoeuvre of so puncturing and counter-puncturing the iris with the point of the knife in its passage through the ante- rior chamber, that in the act of cutting out, a semicircular flap of the iris was formed. This flap of the iris was then cut oft Fig. 52. with a small pair of scissors, introduced through the incision of the cornea. If cataract existed, it was extracted at the same time. 1551. The cases in which Wenzel thus operated, were cases of closed pupil, the lens either having been previously removed by operation, or still remaining but cataractous. Of the opera- tion, however, it is to be observed, that not more is effected by