Topical Dorzolamide May Enhance Peripapillary Choroidal Perfusion in Non-Neovascular Age-Related Macular Degeneration

Abstract

Abstract: : Purpose: To evaluate the effects of dorzolamide on the choroidal and retinal circulation in non-neovascular AMD patients. Methods: All procedures were approved by an IRB, and informed consent obtained. In a prospective, placebo-controlled, double masked study, 36 non-neovascular AMD patients were randomized to receive either topical dorzolamide 2% TID (12 subjects) or placebo (24 subjects) for four months. At baseline and at the 4-month visit, choroidal circulation was assessed with scanning laser ophthalmoscope indocyanine green and retinal angiograms (ICGA) and retinal circulation with fluorescein angiography (FA). ICGA was analyzed by a new area dilution analysis technique, in which four areas in the perifoveal region and two in the temporal peripapillary region are evaluated by graphing intensity of fluorescence over time. FA, at baseline and at 4-month visit, was evaluated for arterio-venous passage (AVP) time by graphing intensity of fluorescence over time of the temporal large retinal vessels. Results: Only 17 (5 -dorzolamide, 12- placebo) out of 36 sets of ICGA and FA (baseline and 4-month) were both in adequate quality for analysis. The main reason for exclusion was poor fixation. AMD patients treated with dorzolamide showed an 84% faster mean choroidal filling time in the peripapillary region (P=0.0015), whereas the placebo group had no significant change. No significant difference was noted in any perifoveal region in either group. Also, no significant change was found in AVP time in either group, although mildly faster AVP time was noted with dorzolamide (21% increase, P=0.19). Conclusions: These studies, using ICGA and FA techniques, indicate that dorzolamide may increase peripapillary choroidal perfusion in non-neovascular AMD patients.

Keywords: age-related macular degeneration • drug toxicity/drug effects • blood supply