Fig. 30.—Iridodialysis. Divergent V (DeWecker).
(a) Iritoectomie.—He entered the stop-keratome through the cornea, made an exact 4 millimeter incision, and then partly withdrew it while letting the aqueous slowly escape. As soon as the iris-membrane floated up against the knife, he pressed forward, making a 2 millimeter incision in the iris. Slowly withdrawing the knife, he introduced the sharp point of the scissors through the iris buttonhole and cut obliquely from either extremity of the incision toward the apex of a triangle, thus making a convergent V (Fig. [29]). He then grasped the resulting triangular flap with the forceps and removed it, leaving an open central pupil.
(b) Iridodialysis.—His second method was a counterpart of Maunoir’s earlier operation, with the addition of iridodialysis. He made the corneal and iris incision with the stop-knife, as in the previous method. Slipping in his scissors he cut from the center of the iris-membrane toward the periphery, and duplicated this incision at an oblique angle to the first, thus making a divergent V (Fig. [30]). This formed a triangular flap which he grasped with forceps and tore from its ciliary attachment by iridodialysis.
DeWecker’s procedure was planned by a skilled operator, and required great dexterity in its execution. When successful, however, the result was most brilliant. Nevertheless, it was impossible to eliminate the danger of hemorrhage and loss of fluid vitreous in iritoectomie, while in iridodialysis there was the added danger of a torn ciliary surface and traction on the ciliary body. His strict injunction to have a trained assistant hold up the speculum blades in order to avoid the loss of fluid vitreous, showed how much he feared this disastrous contretemps. The success of his method of incision is well shown in the illustration of his two cases (Figs. [31] and 32).
Fig. 31.—Pupil by iritoectomie. Two incisions. Convergent V (DeWecker).
Fig. 32.—Stenopaic pupil. Single iris incision (DeWecker).
I have already suggested the possibility of Bowman’s paper before the London Congress of 1872 having given origin to DeWecker’s monograph in 1873. This seems quite reasonable when we consider that Bowman proposed two methods of iridotomy, one his double V operation with a rhomboidal pupil (previously quoted), and the other a visual iridotomy or sphincterotomy, by cutting through the pupillary margin with a blunt corneal knife. These two methods are exact prototypes of DeWecker’s proposals. Furthermore, DeWecker was present at the London Congress where he heard Bowman’s paper, and took part in its discussion. In fact, thirteen years later DeWecker acknowledged[30] that after considering the objections to Bowman’s method of iridotomy “I addressed myself at that time to the search for an instrument which allows the avoidance of all traction on the iris, and which can be handled through a narrow opening, while exerting its cutting action in a plane parallel to the surface of the cornea, against which the diaphragm of the iris applies itself, after the escape of the aqueous humor. The forceps-scissors having been discovered, it was easy for me to cause to be revived the procedure of Janin, and to make it decisively take rank in modern ocular surgery.”