Associations of vision impairment and eye diseases with memory decline over 4 years in China and the United States

Purpose
To examine whether vision impairment and eye diseases are independently associated with memory decline in older adults.

Design
Cohort study.

Methods
We included 8,315 participants aged 50-94 years in China Health and Retirement Longitudinal Study (CHARLS) from China and 8,939 participants aged 50-95 years in Health and Retirement Study (HRS) from the United States in our analysis.

Results
During 4.0 years’ follow-up, the composite memory decreased by 0.16 points in CHARLS. During 3.9 years’ follow-up, the composite memory decreased by 0.51 in HRS. Distance vision impairment was inversely associated with an annual change in composite memory (β [95% CI]: –0.07 [–0.12, –0.01]) and immediate memory (–0.04 [–0.07, –0.02]) in CHARLS, and the corresponding values in HRS were –0.19 (–0.34, –0.05) and –0.07 (–0.13, –0.00), respectively. Near vision impairment was inversely associated with an annual change in delayed memory in CHARLS and composite memory, immediate memory, and delayed memory in HRS. In HRS, the association between distance vision impairment and memory decline was observed in individuals aged <65 years (β [95% CI]: –0.54 [–0.78, –0.30]) but not in those aged ≥65 years (–0.01 [–0.20, 0.18]). Cataract surgery or glaucoma was not significantly associated with memory decline in either CHARLS or HRS.

Conclusion
Distance vision impairment was independently associated with an accelerated rate of memory decline in both China and the United States. Near vision impairment was predictive of decline in delayed memory in China and of decline in composite, immediate, and delayed memory in the United States.