Fig. 11. Fornix-based flap procedure. A. With a scissors or knife, the conjunctiva is incised as close to the limbus as possible. B. The incision is widened. The surgeon uses forceps to stretch the tissue. The scissors cut inferiorly so that no remnant of conjunctiva is left on the globe. C. Tissue is separated from the globe by inserting the scissors with the tips closed and then spreading them bluntly. D. Blunt dissection is continued until the sclera is cleaned adequately. Bleeding from the cut conjunctival vessels is almost inevitable and usually exceeds the bleeding that occurs when a limbus-based flap is raised. E. A radial cut at the edge of the peritomy will improve visualization of the sclera and permit a neat closure of the conjunctiva. F. The cut edge of a fornix-based flap is pulled inferiorly and secured with a 10-0 nylon purse-string suture. G. With large incisions, it usually is necessary to suture both edges to ensure tight closure. (Spaeth GL. Glaucoma surgery. In Spaeth GL (ed). Ophthalmic Surgery: Principles and Practice. Philadelphia: WB Saunders, 1990.)