BackgroundThe purpose of this study was to prospectively evaluate and compare intraocular pressure (IOP) reduction efficacy and safety between bimatoprost and latanoprost-timolol fixed combination (LTFC) in Japanese patients with open-angle glaucoma.MethodsIn this prospective, randomized, non-masked study, after enrolling 70 eyes of 70 Japanese open-angle glaucoma patients who had used latanoprost monotherapy for more than 4 weeks, the subjects were randomly divided into a bimatoprost group or an LTFC group. Both groups were switched from latanoprost to bimatoprost or LTFC for 12 weeks. IOP, conjunctival injection score, corneal epitheliopathy score (area density classification; AD score), tear film break-up time, heart rate, and blood pressure were evaluated at 0, 4, and 12 weeks after switching. The paired t-test and Mann–Whitney U-test were used for the statistical analysis.ResultsAfter 13 of the 70 patients dropped out, 57 were analyzed for IOP reduction and safety. There was a significant decrease in mean IOP at 4 weeks compared with week 0 in both groups (both P<0.0001). Comparisons between the two groups showed no statistically significant differences. The conjunctival injection score was higher in the bimatoprost group than in the LTFC group at 12 weeks (P=0.0091). There were no statistically significant differences between the two drugs in relation to AD score, tear film break-up time, heart rate, and blood pressure.ConclusionBimatoprost and LTFC exhibited similar efficacy for reduction of IOP. Safety results indicated that only the conjunctival injection score at 12 weeks was higher in the bimatoprost group compared with the LTFC group.