Observational Outcomes of Initial Trabeculectomy With Mitomycin C in Patients of African Descent vs Patients of European Descent: Five-Year Results.

Importance: There is evidence that patients of African descent (AD) experience higher surgical failure rate after trabeculectomy without antimetabolites. Objective: To compare outcomes of initial trabeculectomy with mitomycin C in AD patients with those of patients of European descent (ED) and to identify prognostic factors for failure. Design, Setting, and Participants: In this retrospective matched cohort study, 135 eyes of 105 AD patients were matched with 135 eyes of 117 ED patients by age (within 5 years), surgeon, lens status, and follow-up time (within 1 year) from a single tertiary academic center. Interventions: Initial trabeculectomy with mitomycin C. Main Outcomes and Measures: Criteria A, B, and C defined qualified success rates as final intraocular pressure of 18 mm Hg or less, 15 mm Hg or less, and 12 mm Hg or less, respectively, in addition to 20% or more, 25% or more, and 30% or more reduction of intraocular pressure or reduction of 2 or more medications. Kaplan-Meier survival curves were compared with log-rank test in AD and ED patients, and Cox proportional hazard models were used to estimate the influence of race/ethnicity on surgical success accounting for confounding variables. Results: Of the 105 AD patients, 56 (53.3%) were female, and the mean (SD) age was 67.5 (10.4) years; of the 117 ED patients, 64 (54.7%) were female, and the mean (SD) age was 68.2 (10.0) years. For AD patients compared with ED patients, the qualified success rates at 5 years for criteria A were 61% and 67%, respectively (difference, 7.3%; 95% CI, 4.4-10.4); for criteria B, 43% and 60% (difference, 17.6%; 95% CI, 15.2-20.0); and for criteria C, 25% and 40% (difference, 15.8%; 95% CI, 11.1-20.5). On multivariable Cox regression analyses, AD was associated with higher failure rate with criteria B and C for qualified success and with all criteria for complete success (ie, no need for medications). Incidence of bleb leaks was higher in the AD group (29 vs 11 eyes; P = .002). Additionally, AD patients required additional glaucoma surgeries more often than ED patients (47 vs 26 eyes; P = .004). Conclusions and Relevance: African descent was associated with higher failure rates and higher incidence of bleb leaks after initial trabeculectomy with mitomycin C compared with European descent. If this is subsequently shown to be a cause and effect, the findings need to be considered when surgical treatment of glaucoma is contemplated in AD patients.