Abstract
Purpose: :
Retinal Function Imager ® (RFI, Optical Imaging Ltd., Rehovot, Israel) is a novel device offering a noninvasive diagnostic approach to retinal function assessment. The purpose of this study was to evaluate the effect of topical nipradilol, an alpha-beta-blocker as well as a nitric oxide (NO) donor ophthalmic agent for glaucoma, on the retinal microcirculation using RFI in healthy volunteers.
Methods: :
Eight healthy volunteers (mean age, 32.9 years) were recruited and microcirculation velocities at perifovea were quantitatively analyzed by RFI. Intraocular pressure (IOP), blood pressure (BP) were also measured. In a single-blind trial, all measurement was done before and after the instillation of nipradilol or saline twice a day for 2 weeks.
Results: :
Two weeks instillation of nipradilol decreased IOP from 13.3±2.5mmHg to 11.0±1.8mmHg, (p = 0.104). Retinal arterial blood flow velocity significantly increased at 2 weeks after instillation in nipradilol-treated eyes (2.65±0.48mm/sec, 3.02±0.45mm/sec, respectively, p = 0.015). There was no significant difference in retinal venous blood flow velocity (2.46±0.84mm/sec, 2.23±0.29mm/sec, respectively, p = 0.507). Mean BP decreased from 115±6/71±8mmHg to 108±8/65±6mmHg significantly (p<0.001).
Conclusions: :
Our data showed that topical nipradilol significantly increased arterial blood flow velocity at perifovea in human eyes.These results suggested that RFI might be useful to evaluate blood flow velocity in the glaucoma patients, to assess the efficacy of topical glaucoma agent.
Keywords: retina • drug toxicity/drug effects • imaging/image analysis: clinical