Posterior Surgical Revision of Failed Fornix-based Trabeculectomy

To evaluate outcomes after revision of failed fornix-based trabeculectomy using a posterior conjunctival incision and mitomycin C.

Cases were identified using Current Procedural Terminology codes. Information from clinical records was analyzed retrospectively. Complete success was defined as intraocular pressure (IOP) ≤16 mm Hg with no glaucoma medications and IOP reduction of >20% from preoperative levels. Qualified success was defined as IOP≤16 with or without medications and IOP reduction of >20%. Secondary outcomes included IOP, number of glaucoma medications used, visual acuity, and complications.

Sixty eyes of 56 patients underwent surgical revision of failed trabeculectomy. The complete success rate at 1 year was 43.7%, declining to 41.7% at 2 years and all time points up to 5 years; qualified success rates were 68.9% at 1 year and at all subsequent time points. Mean IOP declined from 21.2±7.7 (SD) mm Hg preoperatively to 10.9±4.3 mm Hg at 1 year, to 10.5±3.8 mm Hg at 2 years, and to 9.9±4.6 mm Hg at 3 years. The mean number of glaucoma medications used fell from 2.5±0.5 preoperatively to 1.0±0.4 at 1 year, 0.9±0.4 at 2 years, and 0.9±0.4 at 3 years. Complications included bleb leak in 3 eyes (5.0%), hypotony with choroidal detachment in 3 eyes (5.0%) and hyphema in 1 eye (1.7%). Eight eyes required additional glaucoma surgery.

Surgical bleb revision with mitomycin C using a posterior incision in cases of failed fornix-based trabeculectomy can provide effective control of IOP. This conjunctiva-sparing procedure should be considered as a viable alternative to a tube shunt or repeat trabeculectomy.