Comparison of the intraocular pressure-lowering effect of latanoprost and timolol in patients with chronic angle closure glaucoma - A preliminary study

Objective: To compare the intraocular pressure (IOP)-reducing effect and side effects of 0.005% latanoprost once daily to 0.5% timolol twice daily in patients with primary chronic angle closure glaucoma (CACG). Design: Randomized, double-masked two-center clinical trial. Participants: Thirty-two Asian patients with CACG, defined as glaucomatous optic neuropathy with a compatible visual field defect and at least 6 clock hours of synechial angle closure on gonioscopy were recruited. All patients had previous peripheral iridotomy (PI) with IOP >21 mmHg after PI and were thereafter controlled (IOP <22 mmHg) with one or two pressure-reducing drugs. Intervention: After a washout period, the patients were randomized to a 2-week treatment period with either placebo in the morning and 0.005% latanoprost in the evening or 0.5% timolol twice daily. Main Outcome Measures: The short-term IOP reduction of latanoprost and timolol in patients with CACG, IOP was measured at baseline, and after 2, 7, and 14 days of treatment. In addition, the short-term ocular and systemic adverse events of the two drugs were evaluated. Results: Thirty patients completed the study. Two patients in the timolol group were withdrawn because of inadequate IOP control. Compared with baseline, the IOP after 2 weeks of treatment was statistically significantly reduced by 8.8 +/- 1.1 mmHg (mean +/- SEM, P < 0.001) in the latanoprost group, and by 5.7 +/- 0.9 mmHg (P < 0.001) in the timolol group, The difference in IOP reduction between the two treatment groups was 3.1 +/- 1.5 mm Hg in favor of latanoprost (P = 0.04). The main ocular adverse events reported in both treatment groups were conjunctival hyperemia and discomfort. Conclusions: In this preliminary study, a significantly greater IOP reduction was achieved with 0.005% latanoprost once daily compared with 0.5% timolol twice daily in patients with CACG, The results suggest that latanoprost may be a therapeutic choice for the medical treatment of primary CACG. Ophthalmology 2000;107: 1178-1183 (C) 2000 by the American Academy of Ophthalmology.