Effect of timolol on anterior optic nerve blood flow in patients with primary open-angle glaucoma as assessed by the Heidelberg retina flowmeter.

Abstract

To evaluate the effect of 0.5% timolol maleate on the capillary circulation of the anterior optic nerve head in patients with primary open-angle glaucoma and to compare the results with those obtained in a healthy control group. Twelve patients with nonprogressive glaucoma and 12 age- and sex-matched healthy volunteers were included in this prospective study. Optic nerve head perfusion was examined by the Heidelberg Retina Flowmeter (HRF) in both groups. A 3-week washout period preceded the baseline measurement in the glaucoma group, and ONH blood flow was assessed again after 3 weeks of bilateral topical timolol treatment and 2 hours after timolol application. Intraocular pressure decreased significantly with timolol (P < 0.001). The HRF flow values for patients with glaucoma were comparable to those for a control group at baseline (P = 0.25), 3 weeks after timolol therapy (P = 0.09), and 2 hours after timolol instillation (P = 0.15). The glaucoma group showed no statistically significant change in the HRF parameter flow as compared with baseline, either after 3 weeks of timolol treatment or 2 hours after timolol instillation (P = 0.40). The heart rate and arterial systolic and diastolic blood pressure values showed no alteration after timolol therapy. Patients with nonprogressive glaucoma seem not to have an altered optic nerve blood flow as assessed by the HRF, and timolol treatment does not seem to alter the latter blood flow parameter in such patients.