The Success Rate of Glaucoma Drainage Device Revision.

PRECIS: We report the survival of surgical revision to glaucoma drainage devices for several indications in a large cohort of patients, with an overall success rate of 45% at 36 months.

PURPOSE: To evaluate the outcomes of surgical revision for complications of glaucoma drainage devices.

METHODS: 335 eyes of 318 patients who underwent tube revision or removal at UCLA Jules Stein Eye Institute between 1997 and 2019 were included. The pre-defined primary outcome measure was surgical success of the initial revision, defined as resolution of the condition with no additional revisions required, no functionally significant change in vision, and no instances of IOP > 21 mmHg at two consecutive visits postoperatively. Kaplan-Meier survival analysis was applied to evaluate survival at 36 months based on these criteria. The Wilcoxon paired test was used to compare mean pre- and post-operative intraocular pressure, medication usage, and visual acuity.

RESULTS: Overall, survival of revised tubes at 36 months was 45%. The four most common indications for revision were exposure of the implant (42% of all revisions), occlusion (14%), corneal failure or threat of failure (12%), and hypotony (11%). Survival at 36 months for each of these indications was 44%, 45%, 52%, and 37%, respectively.

CONCLUSIONS: These results suggest that eyes with glaucomatous damage with long-term GDD complications can still have a reasonably successful outcome when a revision is performed. However, with substantial rates of vision loss and a frequent need for additional revisions to manage complications, managing patient expectations for success and making them aware of the likelihood of additional surgeries or failure is important.