Fig. 9.—Iridotomy by Adams’ method (after Lawrence).
Fig. 10.—Occlusion of pupil (Adams).
Fig. 11.—The resulting pupil after iridotomy (Adams).
Here were three elements of success, a sharp knife, a gentle sawing movement, and the most delicate pressure of the instrument. His method was a decided advance, and he reported success in nearly one hundred cases. Others, less skilful, however, failed of success, and the severe criticisms of Scarpa,[16] though evidently unjust and tinged by personal animosity,[17] cast a shadow of doubt on the method.
Fig. 13.—Iris-knife in position to make central pupil (Walton, after Beer).
From that time on for nearly half a century this form of iridotomy was practically abandoned, the pendulum swinging toward the use of scissors, which Maunoir had popularized and Scarpa had indorsed. Walton,[18] however, about 1852, proposed a method closely resembling that of Heuermann and almost identical with that of Beer (vide Fig. [6]). His iris-knife (Fig. [12]) was practically the same as the broad iris-knife of Beer. He incised the cornea near the limbus, and passed the knife across the anterior chamber to the middle of the iris-membrane which he punctured with a sweeping vertical incision (Fig. [13]). If the tissue still retained its elasticity there appeared a long pupillary aperture, elliptical and vertical (Figs. [14] and 15). This incision, however, like all those made through a single set of the iris fibers, was only successful when there was sufficient resiliency remaining in the iris tissue to draw the slit open, and thus keep the edges from uniting. While this method never became very popular, there were some who later practiced it by substituting a very narrow Graefe knife for the iris-knife of Heuermann, Beer and Walton. In fact, this latter procedure still has considerable vogue, both for iridotomy and capsulotomy.
