The Early Effects of Alcohol Consumption on Functional Visual Acuity, Tear Functions, and the Ocular Surface

PURPOSE: We investigated the early effects of alcohol intake on tear functions and ocular surface health in this prospective controlled study. METHODS: Forty-four eyes of 22 subjects (17 males, 5 females; mean age: 35.3 years) who drank 200 mL of 25% Japanese vodka and 44 eyes of age- and sex-matched 22 control subjects who drank water were investigated. Subjects were requested to refrain from alcohol consumption from the previous day and food ingestion 6 hr before the study. Each subject consumed exactly the same order prepared dinner and same quantity of alcohol over the same time frame. Subjects underwent breath alcohol level, tear evaporation and blink rate, tear lipid layer interferometry, tear film break-up time (BUT), fluorescein and Rose Bengal stainings, Schirmer test, and visual analog scale (VAS) evaluation of dry eye symptoms before, as well as 2 and 12 hr after alcohol intake. RESULTS: The mean breath alcohol level was significantly higher in the alcohol group compared to the water group at 2 and 12 hr (P<0.001). The mean tear evaporation increased significantly from 2.5×10-7 to 8.8×10-7 gr/cm2/sec 12 hr after alcohol intake (P<0.001). The mean BUT shortened significantly from 15.0±5.0 to 5.0±2.5 sec 12 hr after alcohol intake. Lipid layer interferometry showed signs of tear film thinning 12 hr after alcohol intake in all subjects of the alcohol intake group, which was not observed in the water group. The mean blink rates increased significantly from 10.6±1.5 blinks/min to 13.5±0.9 blinks/min and 15.1±1.2 blinks/min at 2 and 12 hr, respectively, in the alcohol group (P<0.001). The Schirmer test values decreased significantly 12 hr after alcohol intake (P<0.001). The mean VAS score for dryness increased from baseline significantly in the alcohol group at 12 hr (P<0.001). No significant time-wise changes in tear functions were observed in the water group. CONCLUSION: The tear film and ocular surface epithelia showed early and distinctive quantitative and qualitative changes associated with visual disturbances after alcohol intake.