[Effects of ethanol on intraocular tension in the rabbit (author's transl)]

A 10% solution of ethanol in physiological saline, administered to the Blanc de Bouscat rabbit by the intraperitoneal route, causes a decrease of intraocular tension at a single dose as low as 15 mg per kg. This dose of 15 mg/kg, regularly given during 6 days per weeks, for 4 weeks, determines a progressive fall of intraocular tension during the 3 to 4 first days of each week, and has apparently cumulative effects: then, it remains at a constant level during the following days, and finally recovers its initial value between 2 consecutive weeks. The decrease of intraocular tension seems to be linked to a reduction of the secretory rate of aqueous humor, partly compensated by an increase of outflow resistance. Ethanol rate, as measured in the aqueous humor 120 min after the last injection, may be either equal to or higher than alcoholemia. After 24 hrs, there is no longer any dosable ethanol trace in the aqueous humor and in the blood, while the intraocular tension has reached its minimal value. It seems that a biological damage due to ethanol still persists, while ethanol rate is null in the blood and in the aqueous humor. A great number of authors have tried to find out the possible causes of ocular hypotension determined by high single doses of ethanol (from 200 to 3250 mg per kg) given to various animal species and to man. Proposed hypotheses do not seem to be worth being kept in mind when ethanol doses and very small (15 mg/kg). In the light of works carried out in vitro, it may be supposed that observed hypotensive ocular effects could be linked to central biochemical disorders having repercussions upon the variations of intraocular tension.