Visual impairment bidirectionally linked to dementia in older adults

Self-reported visual impairment (VI) may increase the odds of dementia among older adults over time, suggests a US study, noting that dementia is similarly predictive of VI over time.

“Associations are likely multifactorial and bidirectional and could be explained by intervening variables in the path from VI to dementia, or vice versa, or by common risk factors for pathological processes in both eyes and brain,” the investigators said.

A total of 10,676 participants aged ≥65 years were included in this retrospective, time-to-event study. Cox proportional hazards regression models were fitted to assess the impact of baseline VI on subsequent dementia and of baseline dementia on subsequent VI. The investigators adjusted the models for potential confounders, including demographics, clinical comorbidities, and hearing and physical function limitations.

Of the participants, about 40 percent were aged 65–74 years, 40 percent were aged 75–84 years, and 20 percent were aged ≥85 years. The majority were women (59 percent) and self-identified as non-Hispanic White (68 percent).

The investigators observed subsequent dementia in 1,753 (16 percent) participants with normal cognitive status at baseline and subsequent VI in 2,371 (22 percent) participants with normal self-reported vision at baseline.

In adjusted regression models, those with baseline VI were more likely to develop dementia over subsequent follow-up (hazard ratio [HR], 2.3, 95 percent confidence interval [CI], 2.0–2.6; p<0.001). Similarly, participants with baseline dementia were at greater risk of developing self-reported VI over time (HR, 2.5, 95 percent CI, 2.2–2.8; p<0.001).

“These findings suggest the need for early identification of older adults with visual compromise and consideration of visual disability in the cognitively impaired,” the investigators said.