Efficiency, safety, and patient preference of switching from dorzolamide 1%/timolol 0.5% to brinzolamide 1%/timolol 0.5% while maintaining the prostaglandin F2α analog

Yoshie Shimizu,1 Shunsuke Nakakura,1 Makiko Nishiyama,1 Hitoshi Tabuchi,1 Yoshiaki Kiuchi2 1Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, 2Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima, Japan Background: We investigated the efficiency, safety and patient preference of switching from dorzolamide 1%/timolol 0.5% to brinzolamide 1%/timolol 0.5% while maintaining the prostaglandin F2α analog.Methods: We initially enrolled 44 eyes from 44 primary open angle glaucoma patients, and a total of 42 patients completed the study. All patients were under treatment with various prostaglandin F2α analogs and dorzolamide 1%/timolol 0.5%. While maintaining the prostaglandin F2α analog, dorzolamide 1%/timolol 0.5% was switched to brinzolamide 1%/timolol 0.5%. Conjunctival hyperemia, superficial punctate keratopathy, and intraocular pressure (IOP) were evaluated at baseline and at 4, 12, and 24 weeks. Adverse events and patient preferences, measured using a questionnaire at study initiation and at 24 weeks, were also noted.Results: The IOP was 17.7±1.7, 16.8±2.6, 16.7±2.2, and 16.7±2.4 mmHg at baseline and at 4, 12, and 24 weeks, respectively, with no significant differences in IOP values at any time point (P=0.117, one-way analysis of variance). In addition, no significant differences were found in the incidence of conjunctival hyperemia or SPK score at any time point (all P>0.5, by Kruskal–Wallis test). Based on the evaluation of side effects using the questionnaire, stinging/burning was less common (P=0.042), while blurred vision was more common (P=0.003), after switching to brinzolamide 1%/timolol 0.5%. Regarding patient preferences, 13 patients (31%) preferred dorzolamide 1%/timolol 0.5%, 12 patients (29%) preferred brinzolamide 1%/timolol 0.5%, and 17 patients (40%) preferred neither.Conclusion: When switching from dorzolamide 1%/timolol 0.5% to brinzolamide 1%/timolol 0.5%, the IOP values and incidence of superficial punctate keratopathy and conjunctival hyperemia were sustained throughout the 24-week observation period, and the patient preferences were similar for the two regimens. However, differences were observed in the ocular sensations of stinging/burning with dorzolamide 1%/timolol 0.5% and blurred vision with brinzolamide 1%/timolol 0.5%. Keywords: glaucoma, prostaglandin F2α, brinzolamide, dorzolamide, fixed combination, timolol