Comparing the Efficacy of Latanoprost (0.005%), Bimatoprost (0.03%), Travoprost (0.004%), and Timolol (0.5%) in the Treatment of Primary Open Angle Glaucoma

PURPOSE To compare the efficacy and safety of latanoprost, bimatoprost, travoprost and timolol in reducing intraocular pressure (IOP) in patients with primary open angle glaucoma. METHODS This was a prospective study conducted at a tertiary-care centre. One hundred and forty patients with newly diagnosed primary open angle glaucoma were randomly assigned to treatment with latanoprost (0.005%), bimatoprost (0.03%), travoprost (0.004%) or timolol gel (0.5%); 35 patients were assigned to each group. All patients were followed for 2, 6, and 12 weeks. The main outcome measure studied was the change in IOP at week 12 from the baseline values. Safety measures included recording of adverse events. RESULTS The mean IOP reduction from baseline at week 12 was significantly more with bimatoprost (8.8 mmHg, 35.9%) than with latanoprost (7.3 mmHg, 29.9%), travoprost (7.6 mmHg, 30.8%) or timolol (6.7 mmHg, 26.6%) (ANOVA and Student's t-tests, p < 0.001). Among the prostaglandins studied, bimatoprost produced a maximum reduction in IOP (-2.71; 95% confidence interval [CI], -2.25 to -3.18) followed by travoprost (-1.27; 95% CI, -0.81 to -1.27) and latanoprost (-1.25; 95% CI, -0.79 to -1.71); these values were significant when compared to timolol at week 12 (Bonferroni test, p < 0.001). Latanoprost and travoprost were comparable in their ability to reduce IOP at each patient visit. Ocular adverse-events were found in almost equal proportion in patients treated with bimatoprost (41.3%) and travoprost (41.9%), with a higher incidence of conjunctival hyperemia (24.1%) seen in the bimatoprost group. Timolol produced a significant drop in heart rate (p < 0.001) at week 12 when compared to the baseline measurements. CONCLUSIONS Bimatoprost showed greater efficacy when compared to the other prostaglandins, and timolol was the most efficacious at lowering the IOP. Conjunctional hyperemia was mainly seen with bimatoprost. However, the drug was tolerated well and found to be safe.