The association between visual trajectories and cognitive impairment: insights from the Taiwan Longitudinal Study on Aging

BACKGROUND: Visual impairment (VI) was associated with cognitive impairment. However, different visual trajectories might contribute to different risks of cognitive decline in the elderly. AIMS: This study aimed to evaluate the association between visual trajectories and cognitive impairment. METHODS: Four thousand two hundred eight community-dwelling elder adults were identified from Waves IV-VII (1999-2011) survey of the Taiwan Longitudinal Study on Aging (TLSA). Cognitive function was determined using the Short Portable Mental Status Questionnaire (SPMSQ) scores. Visual impairment was self-reported and visual trajectories were assessed in at least two waves of the survey. Ordinal logistic regression was performed to estimate adjusted odds ratios (adjORs) and 95% confidence intervals (CIs). RESULTS: Participants with visual trajectory from no VI to VI had significantly higher risk of cognitive impairment with an adjOR of 1.69 (95% CI 1.12-2.57) than participants without VI. Compared to participants without VI, participants with persistent VI (adjOR 1.32; 95% CI 0.89-1.96) and with visual trajectory from VI to no VI (adjOR 1.25; 95% CI 0.83-1.88) were not associated with cognitive impairment. A protective association between eyeglasses use and cognitive impairment (adjOR 0.69; 95% CI 0.55-0.87) was found in this study. Importantly, cataract was associated with higher risk of cognitive impairment (adjOR 1.34; 95% CI 1.10-1.62). However, nonsurgical cataract treatment did not show protective effect on cognitive impairment in patients with cataract. CONCLUSIONS AND DISCUSSION: Visual trajectory from no VI to VI is a significant risk factor for cognitive impairment that physicians should pay special attention during community screening.