A Comparison of the Intraocular Pressure-lowering Effect of 0.5% Timolol Maleate and the Docosanoid Derivative of a PGF2α Metabolite, 0.12% Unoprostone, in Subjects with Chronic Open-angle Glaucoma or Ocular Hypertension

Abstract

SummaryThe efficacy of 0.5% timolol was compared with that of the prostaglandin derivative unoprostone in maintaining control of intraocular pressure (IOP) in subjects with chronic open angle glaucoma (CO AG) or ocular hypertension (OH) already responding satisfactorily to β-blocker monotherapy. In a two-centre, double-masked, randomised parallel group study, 40 subjects were placed on 0.5% timolol eyedrops twice daily for two weeks. They were then randomised either to continue with 0.5% timolol or to switch to 0.12% unoprostone, applied twice daily for six weeks. IOP was measured at two-weekly intervals. The status of the conjunctiva, iris, cornea and anterior chamber was kept under observation. Ocular safety was monitored by measurements of visual acuity, and any systemic adverse events were recorded. After six weeks' treatment, there were no statistically significant differences in mean change from baseline IOP within or between treatment groups. For the subjects treated with unoprostone, mean IOP increased by 0.69 mm Hg (p =0.368) while that of the timolol-treated subjects fell by 0.47mm Hg (p = 0.287). The difference in mean IOP between groups was 1.16 mm Hg (p = 0.211, 95% confidence interval [CI] -0.69 to 3.02). The most common complaint was a mild and transient burning sensation on instillation which occurred more frequently in the unoprostone group. In conclusion, an aqueous solution of 0.12% unoprostone isopropyl, applied topically to the eye twice daily for six weeks, was as effective as 0.5% timolol in maintaining control of IOP in subjects with chronic open angle glaucoma or ocular hypertension. Both treatments were safe and well tolerated.