Alcohol Consumption, Genetic Risk, and Intraocular Pressure and Glaucoma: The Canadian Longitudinal Study on Aging.

Purpose: The purpose of this study was to examine the association of alcohol consumption with intraocular pressure (IOP) and glaucoma and to assess whether any associations are modified by a glaucoma polygenic risk score (PRS).
Methods: Cross-sectional analysis of data from the Canadian Longitudinal Study on Aging Comprehensive Cohort, consisting of 30,097 adults ages 45 to 85 years, was done. Data were collected from 2012 to 2015. Alcohol consumption frequency (never, occasional, weekly, and daily) and type (red wine, white wine, beer, liquor, and other) were measured by an interviewer-administered questionnaire. Total alcohol intake (grams/week) was estimated. IOP was measured in mm Hg using the Reichert Ocular Response Analyzer. Participants reported a diagnosis of glaucoma from a doctor. Logistic and linear regression models were used to adjust for demographic, behavioral, and health variables.
Results: Daily drinkers had higher IOP compared to those who never drank (β = 0.45, 95% confidence interval (CI) = 0.05, 0.86). An increase in total weekly alcohol intake (per 5 drinks) was also associated with higher IOP (β = 0.20, 95% CI = 0.15, 0.26). The association between total alcohol intake and IOP was stronger in those with a higher genetic risk of glaucoma (P for interaction term = 0.041). There were 1525 people who reported being diagnosed with glaucoma. Alcohol consumption frequency and total alcohol intake were not associated with glaucoma.
Conclusions: Alcohol frequency and total alcohol intake were associated with elevated IOP but not with glaucoma. The PRS modified the association between total alcohol intake and IOP. Findings should be confirmed in longitudinal analyses.