The Relationship Between Caffeine Intake and Dry Eye Disease

PURPOSE: The aim of this study was to determine the association between caffeine intake and dry eye disease (DED) in the large, population-based LifeLines cohort in the Netherlands. METHODS: DED was cross-sectionally assessed in 85,302 participants (59% female participants) using the Women's Health Study dry eye questionnaire. Dietary caffeine was calculated from the intake of coffee, tea, cola, and energy drinks. Logistic regression was used to investigate the relationship between DED and caffeine, correcting for demographic variables, smoking status, alcohol intake, and 48 comorbidities of DED. RESULTS: The mean (SD; range) age of participants was 50.7 years (12.4; 18-96), and 50,339 (59%) were female. The mean (SD) caffeine intake was 285 (182) mg/d. After correcting for demographics, body mass index, smoking status, and alcohol intake, higher caffeine intake was associated with a decreased risk of Women's Health Study-defined DED [odds ratio (OR) 0.971 per 100 mg/d, 95% CI, 0.956-0.986, P < 0.0005]. When additionally adjusting for medical comorbidities, no significant effect was observed (OR 0.985, 95% CI, 0.969-1.001, P = 0.06). Caffeine's effect on DED was similar in male and female participants and independent of sleep quality and stress at work. Decaffeinated coffee intake was significantly associated with an increased risk of DED, when adjusted for caffeinated coffee, demographics, alcohol intake, smoking status, and comorbidities (OR 1.046 per cup/d, 95% CI, 1.010-1.084, P = 0.01). None of the beverages were significantly associated with the risk of DED, when correcting for intake of the other caffeinated beverages, demographics, smoking status, alcohol intake, and all comorbidities. CONCLUSIONS: Dietary caffeine intake does not seem to be a risk factor for DED in the general population.