Background/aims To investigate the acute effect of ethanol consumption on subfoveal choroidal thickness.

Methods This prospective interventional study included the right eyes of 30 healthy subjects (30 eyes). Ethanol (1.0 g/kg) was administered orally on the first visit. A matching volume of water was administered orally on the second visit. Oral administration of ethanol and water was performed at 14:00, and choroidal thickness was measured every 30 min until 16:00. Change of choroidal thickness after oral administration of ethanol and water was the main outcome measure.

Results At baseline, choroidal mean subfoveal thickness was 299.0±73.4 µm (range, 186.5–472.5 µm) before ethanol consumption and 297.1±71.1 µm (range, 187.0–470.5 µm) before water consumption. After consumption of ethanol, mean subfoveal choroidal thickness increased during the first 60 min and then decreased during the next 60 min, which was a significant change over time (p<0.001). After consumption of water, there was no significant change in mean subfoveal choroidal thickness over time (p=0.310). Comparison of changes in the mean subfoveal choroidal thickness during 120 min showed significant difference between ethanol and water consumption (p<0.001).

Conclusions The results of current study show that consumption of ethanol significantly affected the choroidal thickness. Mean subfoveal choroidal thickness increased during the first 60 min and then decreased during the next 120 min after ethanol consumption.