Visual Impairment and Risk of Dementia: The UK Biobank Study

Purpose: To investigate the relationship between visual impairment (VI) and dementia in the UK Biobank Study. Design: Prospective cohort study. Methods: A total of 117,187 volunteers (aged 40-69 years) deemed free of dementia at baseline were included. Habitual distance visual acuity worse than 0.3 logMAR units in the better-seeing eye was used to define VI. The incident dementia was based on electronically linked hospital inpatient and death records. Results: During a median follow-up of 5.96 years, the presence of VI was significantly associated with incident dementia (hazard ratio: 1.78; 95% confidence interval: 1.18-2.68; P = .006). There was a clear trend between the severity of VI and risk of dementia (P for trend = .002). Conclusions: We found VI was associated with increased risk of dementia, with a progressively greater risk among those with worse visual acuity. Our findings suggested that VI might be a modifiable risk factor for dementia and highlighted the potential value of VI elimination to delay the manifestation of dementia.