ABSTRACT
In a prospective, randomised, double-masked, parallel-group, multi-centre study, 210 patients with primary open angle glaucoma or ocular hypertension were enrolled of whom 167 (timolol 0.1% gel 82, timolol 0.5% 85) completed the study as per protocol. The change in intraocular pressure between baseline and week 12 in the worse eye ('at trough') was 6.3 (SD 3.3) mm Hg on timolol 0.1% gel and 7.0 (2.9) mm Hg on timolol 0.5%; this difference was not statistically significant (p = 0.19). The difference between the two study groups in the change of intraocular pressure from baseline was 0.62 mm Hg; the 90% CI of -0.09 to +1.33 mm Hg was within the pre-specified limits of -1.5 to +1.5 mm Hg demonstrating equivalence between timolol 0.1% gel and timolol 0.5%. The plasma levels of timolol (ng/ml) at 12 weeks in the timolol 0.1% gel group were significantly less than that with timolol 0.5% both before instillation (mean 0.057, SD 0.131 and mean 0.470, SD 0.519 respectively, p = 0.025) and after instillation (mean 0.552, SD 0.992 and mean 2.473, SD 1.780 respectively, p = 0.008). Both treatments were well tolerated with no statistically significant difference between the groups in the occurrence of ocular or systemic adverse events.