Outcomes of Surgical Bleb Revision for Complications of Trabeculectomy

Objective: To describe the results of revision surgery for complications of trabeculectomy in a case series from an academic glaucoma service. Design: Retrospective case series. Participants: A total of 177 eyes of 167 adult patients who underwent revision of trabeculectomy at the Wilmer Eye Institute between 1994 and 2007. Methods: Three indications for surgery were identified: hypotony without leak, bleb leak, and bleb dysesthesia. Revision was deemed successful when all of the following were true: the primary indication was eliminated, further intraocular pressure (IOP)-lowering surgery was not required, no major complication occurred, and a new bleb-related problem did not develop. Patients with less than 3 months of follow-up were excluded unless failure occurred earlier. Surgical procedures included variations on excision of thin or leaking conjunctiva with advancement. Main Outcome Measures: Change in IOP, change in visual acuity, need for further IOP-lowering surgery, and complications after bleb revision. Results: Subjects' mean age was 67 +/- 14 years, 54% were female, and mean follow-up was 2.8 +/- 2.7 years, with a mean interval from trabeculectomy to revision of 3.5 +/- 3.7 years. Overall success rate was 63% (112/177), which was slightly higher for leak repair (65%; 64/98) and hypotony (63%; 32/51) than for dysesthesia (57%; 16/28) indications. By Kaplan-Meier analysis, overall cumulative success rates at 1, 2, 5, and 10 years after bleb revision were 80%, 75%, 50%, and 41%, respectively. IOP and visual acuity improved significantly in both hypotony and leak groups (P values ranging from 0.004 to <0.0001). Additional IOP-lowering surgery was required in 9%. In multivariate regression analysis adjusting for age, gender, and number of prior surgeries, patients with glaucoma other than primary open-angle glaucoma were twice as likely to have failed bleb revision. Conclusions: Surgical bleb revision often provides successful resolution of bleb-related complications. Most patients maintain IOP control without need for further IOP-lowering surgery.