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.