Comparison of intraocular pressure reducing effects of three prostaglandin eyedrops in open-angle glaucoma

Abstract

To compare the efficacy of latanoprost, travoprost and bimatoprost given in the evening on the 24-hour intraocular pressure (IOP) curve in open-angle glaucoma patients. It was a case-control study. Patients with primary open-angle glaucoma were selected for the present study. Twenty-one, 22 and 20 patients were treated once daily with latanoprost, travoprost and bimatoprost for 4 weeks, respectively. Before and four weeks after the treatment, IOP was measured by masked evaluators at 8AM, 10AM, noon, 2PM, 4PM, 6PM, 8PM, 10PM, midnight, 2AM, 4AM and 6AM. Repeated measure analysis of variance was used to compare the IOP responses to the drug regimens for the entire circadian curve. Analysis of variance was used to compare the circadian variations of intraocular pressure. The IOPs of all patients in these 3 groups decreased markedly after 4 weeks. The daily average IOP (mean ± standard deviation) in the latanoprost group decreased from (18.9 ± 2.1) mm Hg (1 mm Hg = 0.133 kPa) to (15.3 ± 2.7) mm Hg, and the extent of the decrease was 19.0%. IOP in the travoprost group decreased from (19.1 ± 3.1) mm Hg to (15.3 ± 2.1) mm Hg, with a decrease of 19.4%. IOP in the bimatoprost group decreased from (18.6 ± 1.9) mm Hg to (14.9 ± 1.9) mm Hg, with a decrease of 19.9%. The effectiveness of the treatments did not differ significantly between these three groups (F = 1.501, P = 0.110). The descending percentage compared with circadian variation ranges before treatment in patients with latanoprost, travoprost and bimatoprost was 31.0%, 31.1% and 31.9%, respectively. In comparison of these three groups, the circadian variations of intraocular pressure did not differ significantly (F = 0.286, P = 0.752). This study demonstrated that latanoprost, travoprost and bimatoprost are all effective in reducing IOP over the 24-hour curve in primary open-angle glaucoma. On the basis of our data, there was no statistically significant difference in the IOP reduction between these three drugs.