The relationship between dry eye and sleep quality

Purpose: Sleep is an important determinant of health and quality of life. This study aimed to clarify the association between dry eye and sleep quality using a large population-based cohort. Methods: 71,761 participants (19-94 yrs, 59.4% female) from the Lifelines cohort in the Netherlands were assessed for dry eye using the Women's Health Study Dry Eye Questionnaire. Sleep quality was evaluated using the Pittsburgh Sleep Quality Index (PSQI). Logistic regression was used to examine the relationship between poor sleep quality (PSQI score > 5) and dry eye, while correcting for age, sex, BMI, education, income, and 51 possible confounding comorbidities, including autoimmune diseases and psychiatric disorders. Results: Overall, 8.9% of participants had dry eye. Of these, 36.4% had poor sleep quality compared to 24.8% of controls (OR 1.52 (95%CI 1.44-1.60), P < 0.0001, corrected for age and sex). After correcting for all comorbidities, dry eye was still associated with poor sleep (OR 1.20 (95%CI 1.11-1.28), P < 0.0001). This relationship was seen across all ages and sexes. Patients with dry eye scored worse on all subcomponents of the PSQI. Almost one-in-two (44.9%) persons with dry eye symptoms "often" or "constantly" had poor sleep quality. This proportion was similar to participants with sleep apnea and osteoarthritis. Additionally, increasing symptom frequency was tied to increased prevalence of poor sleep quality. Conclusions: All components of sleep quality were significantly reduced in participants with dry eye, even after correcting for comorbidities. These results indicate the substantial impact of dry eye on patients' lives, especially for those with frequent symptoms.