PURPOSE: To evaluate the long-term intraocular pressure–lowering efficacy and safety of timolol maleate gel-forming solution 0.5% (Timolol GFS 0.5%, Alcon Research Ltd, Fort Worth, Texas) compared with Timoptic XE 0.5% (Merck, Inc, West Point, Pennsylvania) in patients with open-angle glaucoma or ocular hypertension.

METHODS: Two hundred forty-one patients with open-angle glaucoma or ocular hypertension, who had intraocular pressure between 22 and 36 mm Hg in at least one eye, were randomly assigned in a 2:1 ratio to receive either Timolol GFS 0.5% once daily or Timoptic XE 0.5% once daily, in a 12-month randomized, multicenter, double-masked, prospective study. The primary efficacy variable was mean trough intraocular pressure measured at 8:00 am, approximately 24 hours after dosing.

RESULTS: The Timolol GFS 0.5% group produced significant trough intraocular pressure reductions from a baseline of 4.5 to 5.2 mm Hg (P = .0001), compared with reductions of 4.1 to 5.3 mm Hg (P = .0001) in the Timoptic XE 0.5% group. The difference in mean intraocular pressure between the two treatments was 0.9 mm Hg or less, and the upper 95% confidence limit between groups was 0.92 mm Hg or less at all time points, demonstrating both clinical and statistical equivalence. A similar percentage of patients in the Timolol GFS 0.5% group (71%) and Timoptic XE group (72%) had clinically relevant reductions in intraocular pressure. There was no significant difference in the safety profiles of the two treatments.

CONCLUSION: Both treatments were clinically effective in lowering intraocular pressure and maintaining the reductions over long-term use. Timolol GFS 0.5% is a safe and effective therapy for open-angle glaucoma or ocular hypertension and is both clinically and statistically equivalent to Timoptic XE 0.5% in reducing intraocular pressure.