Michigan Center on the Demography of Aging (MiCDA) researchers Joshua Ehrlich & Ken Langa and co-authors Bonnielin K Swenor, and Yunshu Zhou, find poor vision is associated with the development of CIND. The association of VI and dementia appears to be due to the higher risk of dementia among individuals with CIND. They investigated the association of vision impairment with transitions from cognitively normal to cognitive impairment no dementia (CIND) to dementia, using data from the population-based Aging, Demographics and Memory Study (ADAMS).
Joshua R Ehrlich, MD, MPH, Bonnielin K Swenor, PhD, MPH, Yunshu Zhou, MS, Kenneth M Langa, MD, PhD, The Longitudinal Association of Vision Impairment with Transitions to Cognitive Impairment and Dementia: Findings from The Aging, Demographics and Memory Study, The Journals of Gerontology: Series A, 2021;, glab157, https://doi.org/10.1093/gerona/glab157
Background: Vision impairment (VI) is associated with incident cognitive decline and dementia. However, it is not known whether VI is associated only with the transition to cognitive impairment, or whether it is also associated with later transitions to dementia.
Methods: We used data from the population-based Aging, Demographics and Memory Study (ADAMS) to investigate the association of visual acuity impairment (VI; defined as binocular presenting visual acuity <20/40) with transitions from cognitively normal (CN) to cognitive impairment no dementia (CIND) and from CIND to dementia. Multivariable Cox proportional hazards models and logistic regression were used to model the association of VI with cognitive transitions, adjusted for covariates.
Results: There were 351 participants included in this study (weighted percentages: 45% male, 64% age 70-79 years) with a mean follow-up time of 4.1 years. In a multivariable model, the hazard of dementia was elevated among those with VI (HR=1.63, 95%CI=1.04-2.58). Participants with VI had a greater hazard of transitioning from CN to CIND (HR=1.86, 95%CI=1.09-3.18). However, among those with CIND and VI a similar percentage transitioned to dementia (48%) and remained CIND (52%); there was no significant association between VI and transitioning from CIND to dementia (HR=0.94, 95%CI=0.56-1.55). Using logistic regression models, the same associations between VI and cognitive transitions were identified.
Conclusions: Poor vision is associated with the development of CIND. The association of VI and dementia appears to be due to the higher risk of dementia among individuals with CIND. Findings may inform the design of future interventional studies.