Comparison of the intraocular pressure-lowering effect and safety of brimonidine/timolol fixed combination and 0.5 % timolol in normal-tension glaucoma patients

Purpose To compare the therapeutic efficacy and safety of brimonidine/timolol fixed-combination (BTFC) and 0.5 % timolol ophthalmic solution in normal-tension glaucoma (NTG) patients. Methods This was a multi-institution, randomized, active-controlled, open-label, parallel-group study. After a full ophthalmic and glaucoma examination, a total of 110 NTG patients—55 undergoing therapy with BTFC and 55 0.5 %, with timolol—participated in this study. Among them, 1 failed to meet the inclusion/exclusion criteria, 10 revoked their consent to participate in the study, 3 had adverse reactions, and 1 had a drug adherence rate of less than 70 %. Ultimately, a total of 95 patients—48 in the BTFC group and 47 in the 0.5 % timolol group—completed the study. The study visits took place at baseline and at 4 and 12 weeks. Diurnal IOP was measured at 9 a.m., 11 a.m., and 5 p.m. during the baseline visit and the visit at 12 weeks after eye-drop instillation. At each follow-up visit, compliance was assessed. Throughout the study, all adverse events were recorded and monitored by the investigators. Results The average difference in IOP change measured at 11 a.m. 12 weeks after administration between the two groups was 2.10 ± 2.59 mmHg. The BTFC group had a better IOP-lowering effect at all time points than did the 0.5 % timolol group. The ratio of patients whose average IOP had decreased by >20 % after 4 and 12 weeks was 50 and 56 % in the BTFC group, respectively, whereas it was 29.41 and 23.53 % in the 0.5 % timolol group, respectively ( p = 0.034,