Stephanie Chen, Suzann Pershing; Longitudinal impact of visual impairment on cognitive function in the US. Invest. Ophthalmol. Vis. Sci. 2018;59(9):5167.
Purpose : While visual impairment has been shown to be associated with worse cognitive performance in the US population of older adults, the temporal relationship between the two remains unclear. We performed a time-to-event study of Medicare beneficiaries to investigate the longitudinal impact of visual impairment on cognitive function.
Methods : We used the National Health and Aging Trends Study (NHATS), 2011-2015 cycles. A total of 7,075 participants aged 65 years and older were included. Cox proportional hazards models with time-varying covariates were constructed to evaluate the impact of self-reported visual impairment on probable or possible dementia, as classified per NHATS protocol. Regression models were adjusted for potential confounding variables, including demographics, clinical risk factors, and hearing and physical function impairments; p<0.05 was considered statistically significant.
Results : At the initial survey, of the 7,075 participants included in the analysis, the largest proportion (39%) were between 75-84 years of age (Table 1). The majority were female (60%) and 69% self-identified as non-Hispanic White. Dementia was observed in 1,114 (16%) respondents. In the crude regression analysis, participants with self-reported visual impairment were at significantly higher risk of developing probable or possible dementia over subsequent followup (HR=4.4, CI: 3.9-5.0, p<0.001), compared to those without visual impairment. This association persisted after full adjustments for covariates (HR=2.1, CI: 1.8-2.5, p<0.001). Similar results were found for distance as well as near vision.
Conclusions : Using time-to-event analysis, self-reported visual impairment in the US Medicare population may be associated with greater risk of cognitive decline, suggesting a need for early identification of older adults with visual compromise.