The association between vision impairment and cognitive outcomes in older adults: a systematic review and meta-analysis

Abstract

Objectives

To provide a quantitative synthesis of studies on the relationship between vision impairment (VI) and cognitive outcomes in older adults.

Method

A systematic search was undertaken of relevant databases for original articles published before April 2020. Random effect models were used to obtain pooled estimates of the associations between VI and cognitive outcomes (cognitive impairment and dementia) with subgroup analyses of VI measures, cross-sectional associations of VI with cognitive impairment, and longitudinal associations of baseline VI with incident cognitive impairment and dementia. Potential sources of heterogeneity were explored by meta-regression. Publication bias was evaluated with Egger’s test.

Results

Sixteen studies including 76,373 participants were included in this meta-analysis, with five cross-sectional studies and eleven longitudinal studies. There was a significantly increased risk of cognitive outcomes with VI identified by subjective measures (odds ratio (OR)=1.63; 95% confidence interval (CI): 1.26–1.99) and objective measures (OR = 1.59; 95% CI: 1.40–1.78). The odds of baseline cognitive impairment were 137% higher in older adults with VI compared with those without VI (OR = 2.37, 95% CI: 1.84–3.03) at baseline. Compared with older adults without VI at baseline, those with baseline VI had a higher relative risk (RR) of incident cognitive impairment (RR = 1.41; 95% CI: 1.31–1.51) and dementia (RR = 1.44, 95% CI: 1.19–1.75).

Conclusions

VI was associated with increased risks of cognitive impairment and dementia across cross-sectional and longitudinal studies. Additional research and randomized clinical trials are warranted to examine the implications of treatment for VI, such as wearing glasses and cataract surgery, to avoid cognitive impairment and dementia.

Keywords:

• Vision impairment
• cognitive impairment
• dementia
• meta-analysis
• older adults

Disclosure statement

No potential conflict of interest was reported by the authors.

Authors’ contributions

Study concept and design: GYC, ZSC and BBX. Acquisition, analysis, or interpretation of data: GYC, ZSC and BBX. Drafting of the manuscript: GYC, ZSC and BBX. Critical revision of the manuscript for important intellectual content: GYC, ZSC, SSY, KPW, ZTH, HXS, YL, CMDF, YHH, BBX. Statistical analysis: ZSC and GYC. Administrative, technical, or material support: GYC, ZSC and BBX.

Additional information

Funding

This research was supported by National Natural Science Foundation of China (81703304 and 81973130) and Peking University Medicine Seed Fund for Interdisciplinary Research (BMU2018MX003).