Abstract
Abstract: :
Purpose:There is evidence that acute alcohol consumption causes ocular hypotension and peripheral vasodilatation. The current study investigated the effects of intravenously administered ethanol on retinal vessel diameters in healthy volunteers. Methods:12 healthy male volunteers were included in the study. Ethanol (0.35g/kg) or placebo (NaCl) were administered intravenously for 40 minutes in a randomized, double masked, two way cross over design. Retinal vessel diameters were measured before administration, 10 minutes before the end of infusion as well as 10, 30, 50, 70 and 90 minutes after cessation of the infusion with a Retinal Vessel Analyzer. Intraocular pressure, systemic blood pressure and blood ethanol concentration were determined at the beginning of each measurement period. Results:Intravenous administration of ethanol increased blood ethanol concentration from 0.00±0.00‰ to 0.56±0.10‰. Ethanol tended to decrease blood pressure and reduced IOP. Accordingly, ocular perfusion pressure did not change. 10 minutes after cessation of the infusion blood ethanol concentration started to drop to 0.50±0.06‰, 0.39±0.04‰, 0.32±0.05‰, 0.27±0.05‰ and 0.22±0.06‰, respectively. Retinal arterial diameters increased after administration of ethanol by a maximum of +4.16±4.00% (ANOVA, p=0.038). Administration of ethanol did not affect retinal venous diameters. Neither arterial nor venous diameters were influenced by administration of placebo. Conclusions:Intravenous administration of ethanol increases retinal arterial diameters, whereas venous diameters remained unchanged. Whether this is related to an osmotic effect or to a hitherto unidentified mechanism remains to be clarified.
Keywords: retina • pharmacology