Purpose:
To compare the intraocular pressure (IOP) effect and safety of the dorzolamide/timolol maleate fixed combination (DTFC) bid versus bimatoprost qpm in primary open-angle glaucoma patients who are insufficiently controlled on latanoprost (historical or current IOP of less than or equal to 22 mm Hg in at least one eye).
Methods:
A prospective, double-masked, randomized, active-controlled, crossover comparison in which patients discontinued their current glaucoma medication(s) and returned in 6 weeks for baseline diurnal curve testing every two hours (8 AM to 8 PM). Patients with IOPs of 22-29 mm Hg inclusive at 8 AM in at least one eye were randomized to either bimatoprost qpm and placebo qam or DTFC bid. Patients returned in 8 weeks for the Period 1 diurnal curve and were switched to the opposite treatment. Patients again returned in 8 weeks for the Period 2 diurnal curve. Patients had a safety IOP check at Week 2 in each treatment period.
Results:
Twenty patients completed this study. The mean baseline diurnal IOP was 24.4 ± 0.43 mm Hg. After 8 weeks of treatment, the mean diurnal IOP was 18.5 ± 2.5 mm Hg for DTFC and 17.4 ± 1.9 mm Hg for bimatoprost (P = 0.059). The IOPs at each individual time point are shown in the Table. No significant differences were found between DTFC and bimatoprost for the mean diurnal IOP or individual time points except at 6 PM by a paired t-test within the ANOVA model following a Bonferroni correction of α/4. The most common ocular adverse event was stinging upon instillation (n = 8 [40%], P = 0.001) with DTFC. There were no discontinuations in this study.
Conclusions:
This study suggests that patients who are insufficiently controlled on latanoprost can obtain generally statistically similar IOP control by switching to either DTFC or bimatoprost.Table: IOP (mean mm Hg ± SD)
Clinical Trial:
www.clinicaltrials.gov NCT00273455
Keywords: intraocular pressure • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials