This method is simply an elaboration of the one proposed by Maunoir, in which, instead of forming one divergent V, Bowman has made a duplicate incision on the opposite side, and by joining the bases of these two resultant triangles has caused them to take the shape of a rhomboid, thus <>. [Illustration: Fig. 27.--Stop keratomes, straight and angular (De Wecker).] [Illustration: Fig. 28.--Forceps-scissors (pinces-ciseaux) (DeWecker).] DeWecker,[29] in 1873, published his admirable monograph on iridotomy, in which he proposed the operation which bears his name, and which has long stood as the best recognized method of this procedure. He advocated two different ways of performing this: 1, simple iridotomy, and 2, double iridotomy. [29] De Wecker, Louis: Annales d’Oculistique, Sept., 1873, p. 123, et seq. 1. _Simple Iridotomy._--This is practically the same operation as Critchett’s sphincterotomy and Bowman’s visual iridotomy, although differently executed. It has been supplanted in our day by iridectomy, and does not, therefore, come within the purview of this discussion. 2. _Double Iridotomy._--He rightly claimed that this was both antiphlogistic and optical in its purpose. He employed two distinct methods, which he designated as (_a_) iritoectomie, and (_b_) iridodialysis. The instruments he used were a small stop-keratome (Fig. 27) and a pair of specially devised fine iris scissors (pinces-ciseaux) (Fig. 28), one blade being sharp pointed and the other blunt. These scissors were a great mechanical advance over all previous instruments of this kind, and undoubtedly proved to be a most important element in the success of his procedure. [Illustration: Fig. 29.--Iritoectomie. Convergent V (DeWecker).] [Illustration: 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.