A Comparison of the Intraocular Pressure-lowering Effect of 0.5% Timolol Maleate and the Docosanoid Derivative of a PGF_2αMetabolite, 0.12% Unoprostone, in Subjects with Chronic Open-angle Glaucoma or Ocular Hypertension

Abstract

The 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 (COAG) or ocular hypertension (OH) already responding satisfactorily to beta-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 0.47 mm 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.

An evaluation of the effect of unoprostone isopropyl 0.15% on ocular hemodynamics in normal-tension glaucoma patients

“…Unoprostone isopropyl has been shown to have good efficacy in lowering IOP in patients with primary openangle glaucoma or ocular hypertension [1,31,42], as well as in normal-tension glaucoma patients [9]. Such efficiency could not be confirmed in the present study.…”

“…The drug is thought to lower IOP by increasing aqueous humor outflow, while aqueous humor production remains unaffected [40,44], and to produce a good lowering of IOP in patients with glaucoma and ocular hypertension [1,9,31,42]. Although lowering of IOP remains the mainstay in the management of glaucoma, the importance of other pathogenic aspects become more and more evident.…”

“…Unoprostone isopropyl 0.12% appears to have good efficacy in lowering IOP in patients with primary open-angle glaucoma or ocular hypertension [1,31,42], as well as in those with normal-tension glaucoma [9], and a good safety profile [1,42]. Furthermore, it has been suggested that instillation of unoprostone isopropyl can increase blood flow in the choroid-retina of human eyes [27,28].…”

Effect of Topical Unoprostone Isopropyl on Optic Nerve Head Circulation in Controls and in Normal-Tension Glaucoma Patients

“…5,[11][12][13][14] In this study, the participants were healthy volunteers and NTG patients, and almost all of the NTG patients had IOPs lower than 15 mmHg. Thus, it is not surprising that we did not see a significant IOP lowering effect.…”

Therapeutic potential of prostaglandin analogues in glaucoma

“…The IOP reduction at the 8 AM trough was 20 -28% for timolol and 16 -18% for unoprostone. In another small parallel group study patients already satisfactorily monitored on β-blockers was randomised to proceed with timolol or switch to unoprostone twice daily [127]. The IOP did not differ between the groups that received unoprostone and timolol.…”