Visual impairment and depressive symptoms in an older Australian cohort: longitudinal findings from the Blue Mountains Eye Study

AIMS: To assess the association between visual impairment (VI) and subsequent presence of depressive symptoms among older persons. METHODS: Of the 3654 baseline participants (aged over 49 years) of the Blue Mountains Eye Study, 2334, 1952 and 1149 were re-examined after 5, 10 and 15 years, respectively. VI was defined as best-corrected visual acuity <6/12 in either or both eyes. Presence of depressive symptoms was defined if mental health index (MHI) scores <59 or incident use of antidepressant medications. Persons with VI detected at the 5-year or 10-year follow-up visits were assessed for depressive symptoms in 5 years. Persons with VI detected at baseline or the 5-year follow-up were assessed for depressive symptoms over 10 years. Controls were persons without VI over the corresponding period. Discrete logistic regression models with time-dependent study and outcome variables were used, adjusting for potential confounders. RESULTS: Of 1568 participants who had the MHI assessed at two consecutive visits, 226 had bilateral or unilateral VI detected 5 years earlier and 120 had VI detected over 10 years earlier. Depressive symptoms were reported in 27% and 31.6% of cases with VI detected 5 and over 10 years earlier, respectively, compared with 10.8%-11.5% of controls. There was a significantly greater odds of presenting depressive symptoms among VI cases detected 5 years earlier (OR, 3.06, 95% CI 1.72 to 5.44), but this was non-significant for cases detected over 10 years earlier (OR 1.29, 95% CI 0.84 to 1.98). CONCLUSIONS: VI was associated with subsequently presenting depressive symptoms over 5 years among older persons.