Incisional therapies: Trabeculectomy surgery

Trabeculectomy with an antimetabolite is considered the gold standard for the surgical management of glaucoma. Surgical management for glaucoma was first described in 1857 by Von Graefe, who reported that by removing a large piece of the iris he could help many patients with glaucoma. In 1909, Elliot described a full-thickness filtering procedure by using a trephine to make an anterior sclerectomy under a conjunctival flap, coupled with a peripheral iridectomy. Uncontrolled transclerostomy flow with resulting hypotony was the trigger for most surgeons to switch from full-thickness sclerostomy to a partial-thickness fistula. The guarded fistula was first suggested in 1961 by Sugar but was only published in 1968 by Cairns. The obstruction of the aqueous humor was assumed to be at the juxtacanalicular portion of the trabecular meshwork, and the outflow system distal to the juxtacanalicular meshwork (primarily Schlemm's canal and the distal collector channels) was thought to be normal in patients with glaucoma. Therefore, the primary goal of the trabeculectomy was to eliminate the obstruction to aqueous humor outflow at the inner aspect of Shlemm's canal (Figs. 65.1 and 65.2).