Sleep disturbance and incident depressive symptoms in patients with glaucoma: a longitudinal study of the LIGHT cohort

AIMS: To investigate whether baseline sleep disturbance is associated with an increased risk of incident depressive symptoms in patients with glaucoma. METHODS: In our prospective cohort study, a total of 120 patients with glaucoma who had no depressive symptoms at baseline (mean age 70.1 years) were included. Depressive symptoms, defined as a Geriatric Depression Scale score of 6 or greater, were assessed at baseline and at annual follow-up visits. Sleep disturbance was defined as a Pittsburgh Sleep Quality Index score of 6 or greater. RESULTS: During a median follow-up of 3.94 years, 29 of 120 patients developed depressive symptoms. Kaplan-Meier analysis with the log-rank test showed a higher cumulative incidence of depressive symptoms in the group with baseline sleep disturbance than in the group without sleep disturbance (p=0.021). In Cox proportional hazards models, sleep disturbance was associated with an increased risk of incident depressive symptoms (HR 2.32; 95% CI 1.11 to 4.83). Results remained consistent after adjustment for potential confounders, including visual acuity (HR 3.03; 95% CI 1.25 to 7.33). A significant interaction was observed between sleep disturbance and glaucoma severity in relation to incident depressive symptoms (p=0.021). An association between sleep disturbance and incident depressive symptoms was observed in the non-severe glaucoma group (p<0.001), whereas no significant association was found in the severe glaucoma group. CONCLUSIONS: Baseline sleep disturbance was independently associated with a higher risk of incident depressive symptoms in patients with glaucoma, irrespective of visual impairment.