Visual impairment and its association with cognitive impairment: the Handan Eye Follow-up Study.

Abstract

To investigate the association between visual impairment (VI) and cognitive impairment in middle-aged and older adults from a rural Chinese population. The Handan Eye Follow-up Study was conducted between 2012 and 2013. All participants underwent a standardised ophthalmic examination, structured interview and mobility performance assessment. The ophthalmic examination included visual acuity (VA) measurement and a comprehensive clinical eye examination. The interview collected demographic characteristics, cognitive status assessed by the Mini-Mental State Examination (MMSE) and general information related to medical conditions. Mobility performance was evaluated using walking speed tests, standing balance tests and the Timed Up and Go Test. Of the 5394 participants in the Handan Eye Follow-up Study, 3794 were aged ≥50 years, of whom 3650 completed both VA and cognitive assessments. The prevalence of distance VI and near VI was 27.53% and 91.99%, respectively. Linear regression analyses revealed that distance VI was associated with a 1.53-fold higher likelihood of poorer MMSE scores after adjustment for demographic variables (p<0.01); however, this association was not statistically significant after further adjustment for all covariates (p=0.23). Near VI was associated with a 2.21-fold higher likelihood of poorer MMSE scores following initial adjustment (p=0.025), and this association remained significant after full adjustment (OR= 3.44, p=0.028). Near VI was associated with poorer cognitive performance in a rural Chinese population of middle-aged and older adults, highlighting the potential role of correctable vision loss in cognitive health.