To demonstrate that the statistical analysis is robust, the random-effects model for IOP reduction at peak was repeated after excluding both arms of Maruyama and Shirato8 (BB at peak and TCAI at peak) and 2 of the 3 arms of Reis et al9 (AA at peak and TCAI at peak). Although both clinical trials met our initial criteria for inclusion in the meta-analysis, there were factors in both studies that had the potential to alter the outcomes of the meta-analysis. In the case of Maruyama and Shirato, dorzolamide, 1%, and carteolol, 2%, were used, as opposed to the usual dorzolamide, 2%, and carteolol, 1%, used in the United States and Europe. Second, although only 19% of subjects had normal-tension glaucoma, the mean baseline IOP (without any therapy) was 19.1 mm Hg.8 Eyes with lower baseline IOPs are known to experience a smaller magnitude of IOP reduction with ocular hypotensive therapy. In Reis et al,9 eyes, rather than subjects, were randomized to adjunctive therapy with brimonidine, 0.2%, brinzolamide, 1%, or timolol, 0.5%. Accordingly, it may have been possible for a subject to have been receiving timolol in one eye and another agent in the fellow eye. In light of the potential fellow-eye IOP-lowering effect with timolol, the meta-analysis was repeated after excluding the brimonidine and brinzolamide arms from this study. To clarify, the meta-analysis of peak efficacy was repeated, excluding both arms of Maruyama and Shirato and simultaneously excluding the brimonidine and brinzolamide arms of Reis et al. Both of these studies only contributed data regarding efficacy at peak. After exclusion of these study arms, the statistical significance of comparative efficacy analyses at peak were unchanged.