J E Grunwald1, S Mathur, J DuPont. 1. Department of Ophthalmology, Scheie Eye Institute, School of Medicine, University of Pennsylvania, Philadelphia 19104, USA.
Abstract
PURPOSE: To study the effect of a single dose of topical dorzolamide hydrochloride 2%, a carbonic anhydrase inhibitor, on the retinal circulation of normal subjects. METHODS: Measurements of the effect of dorzolamide hydrochloride were performed in 20 normal subjects using bidirectional laser Doppler velocimetry and monochromatic fundus photography. In a double-masked randomized design, one eye received one drop of dorzolamide hydrochloride 2 % and the other eye one drop of placebo. Vessel diameter, maximum erythrocyte velocity and volumetric blood flow rate were measured in a main temporal vein of each eye before the drops, and then, 2 h later. RESULTS: Following treatment, intraocular pressure decreased by 12% in the dorzolamide-treated eye (p = 0.0004, paired Student's t-test) and by 4% in the placebo-treated eye, p = 0.04). No significant changes in venous diameter, maximum erythrocyte velocity, and volumetric blood flow rate were observed in the dorzolamide-treated eyes (0.6%, 2.6% and 1.4%, respectively) or the placebo-treated eyes (1%, 3.7% and 1.6%, respectively). CONCLUSIONS: A single drop of dorzolamide hydrochloride does not cause any significant change in any of the hemodynamic parameters measured. With the variability of our measurements, we have about 89% power to detect average 10% change in volumetric blood flow rate if significance testing is performed at p = 0.05 level.
RCT Entities:
PURPOSE: To study the effect of a single dose of topical dorzolamide hydrochloride 2%, a carbonic anhydrase inhibitor, on the retinal circulation of normal subjects. METHODS: Measurements of the effect of dorzolamide hydrochloride were performed in 20 normal subjects using bidirectional laser Doppler velocimetry and monochromatic fundus photography. In a double-masked randomized design, one eye received one drop of dorzolamide hydrochloride 2 % and the other eye one drop of placebo. Vessel diameter, maximum erythrocyte velocity and volumetric blood flow rate were measured in a main temporal vein of each eye before the drops, and then, 2 h later. RESULTS: Following treatment, intraocular pressure decreased by 12% in the dorzolamide-treated eye (p = 0.0004, paired Student's t-test) and by 4% in the placebo-treated eye, p = 0.04). No significant changes in venous diameter, maximum erythrocyte velocity, and volumetric blood flow rate were observed in the dorzolamide-treated eyes (0.6%, 2.6% and 1.4%, respectively) or the placebo-treated eyes (1%, 3.7% and 1.6%, respectively). CONCLUSIONS: A single drop of dorzolamide hydrochloride does not cause any significant change in any of the hemodynamic parameters measured. With the variability of our measurements, we have about 89% power to detect average 10% change in volumetric blood flow rate if significance testing is performed at p = 0.05 level.
Authors: G Fuchsjäger-Mayrl; B Wally; G Rainer; W Buehl; T Aggermann; J Kolodjaschna; G Weigert; E Polska; H-G Eichler; C Vass; L Schmetterer Journal: Br J Ophthalmol Date: 2005-10 Impact factor: 4.638
Authors: Saloni Walia; Gerald A Fishman; Robert S Molday; Frank M Dyka; Nalin M Kumar; Mary A Ehlinger; Edwin M Stone Journal: Am J Ophthalmol Date: 2008-10-02 Impact factor: 5.258