Association between retinopathy and risk of dementia in a general Japanese population: the Hisayama Study

We investigated the association of retinopathy with the risk of dementia in a general older Japanese population. A total of 1709 population-based residents aged 60 years or older without dementia were followed prospectively for 10 years (2007-2017). They underwent color fundus photography in 2007. Retinopathy was graded according to the Modified Airlie House Classification. Main outcome was the Incidence of dementia. A Cox proportional hazards model was used to estimate the hazard ratios (HRs) and their 95% confidence intervals (CIs) for the risk of dementia by the presence of retinopathy. During the follow-up period, 374 participants developed all-cause dementia. The cumulative incidence of dementia was significantly higher in those with retinopathy than those without (p < 0.05). Individuals with retinopathy had significantly higher risk of developing dementia than those without after adjustment for potential confounding factors (HR 1.64, 95% CI 1.19-2.25). Regarding the components of retinopathy, the presence of microaneurysms was significantly associated with a higher multivariable-adjusted HR for incident dementia (HR 1.94, 95% CI 1.37-2.74). Our findings suggest that, in addition to systemic risk factors, retinal microvascular signs from fundus photography provide valuable information for estimating the risk of developing dementia.