Fig. 10. Peripheral iridectomy with the use of a preplaced suture to retract the edges of the incision. A. An incision is made through two thirds of the thickness of the sclera directly at the corneoscleral sulcus. B. A 9-0 white virgin silk suture is placed so that it will be able to be retracted from the depths of the incision. C. The suture is looped and used to retract the edges of the incision superiorly and inferiorly. The incision is completed, permitting prolapse of a small knuckle of iris. D. The iris is grasped with a fine-toothed forceps. E. The iris is pulled over the blade of the DeWecker scissors; after the position of the iris is noted, the blades are closed and the tissue is excised. F. The tip of an irrigator is placed just inside the incision, with care taken to ensure that it does not enter the anterior chamber. Remnants of the pigment epithelium are flushed away, and the iris is permitted to return to its proper position so that the pupil is completely round. (Spaeth GL. Glaucoma surgery. In Spaeth GL (ed). Ophthalmic Surgery: Principles and Practice. Philadelphia: WB Saunders, 1990.)