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

Purpose: To evaluate the effect of 0.5% timolol maleate on the capillary ci rculation of the anterior optic nerve head in patients with primary open-an gle glaucoma and to compare the results with those obtained in a healthy co ntrol group. Patients and Methods: Twelve patients with nonprogressive glaucoma and 12 a ge- and sex-matched healthy volunteers were included in this prospective st udy. Optic nerve head perfusion was examined by the Heidelberg Retina Flowm eter (HRF) in both groups. A 3-week washout period preceded the baseline me asurement in the glaucoma group, and ONH blood flow was assessed again afte r 3 weeks of bilateral topical timolol treatment and 2 hours after timolol application. Results: Intraocular pressure decreased significantly with timolol (P < 0.0 01). The HRF flow values for patients with glaucoma were comparable to thos e 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 glaucom a group showed no statistically significant change in the HRF parameter flo w 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 s ystolic and diastolic blood pressure values showed no alteration after timo lol therapy. Conclusions: Patients with nonprogressive glaucoma seem not to have an alte red optic nerve blood flow as assessed by the HRF, and timolol treatment do es not seem to alter the latter blood flow parameter in such patients.