A prospective study of the bi-directional association between vision loss and depression in the elderly.

Abstract : BACKGROUND: Increasing visual impairment (VI) with age has been associated with mental health problems but the question of temporal direction and reverse causality has not been addressed previously. Our objective was to prospectively examine the bi-directional association of VI and visual function (VF) loss with depressive symptoms in the elderly. METHODS: The cohort comprised 4216 participants (40.2% men) aged 65 and over with 10 years of follow-up. Near VI was defined using measured usual-corrected binocular acuity while distance VF was self-declared. Participants having a major depressive episode or a Center for Epidemiologic Studies Depression Scale score ≥ 16 were classified as having depressive symptomatology. Longitudinal analyses used mixed logistic models for repeated evaluations. RESULTS: After adjustment for demographic factors, participants with moderate to severe near VI at baseline had increased odds of developing depressive symptomatology (Odds Ratio [OR]=1.60; 95% Confidence Interval [CI]=1.08-2.38), but after multiple adjustments the association fell below the significance level. A 2-year decrease in distance VF was associated with increased odds of depressive symptomatology during follow-up after multiple adjustments (OR=3.03; 95% CI=1.75-5.23). Baseline depressive symptomatology was not associated with incident near VI but was associated with VF loss after multivariate adjustment (OR=1.62; 95% CI=1.15-2.28). LIMITATIONS: The causes of VI have not been recorded. CONCLUSIONS: The relation of vision loss to onset of depressive symptomatology differs according to near VI or distance VF and declines across time. A reverse strong association was found between baseline depression and incident loss of distance VF suggesting a downward spiral of events.