Near Vision Impairment Is Associated With Cognitive Impairment in Type 2 Diabetes

The objective of this study was to assess the relationship between vision and cognitive impairment in patients with type 2 diabetes mellitus (DM) who are at risk of both conditions.

This was a cross-sectional study.

Persons with type 2 DM underwent a comprehensive clinical examination. Distance and near vision tests were performed, and presence and severity of diabetic retinopathy and diabetic macular edema, indicators of DM control such as fasting plasma glucose and glycosylated hemoglobin, and anthropometric measures were assessed using standardized protocols. Depression status and level of physical activity were measured using validated questionnaires. Adjusted logistic regression models were used to examine the association between near and distance vision impairment and cognitive impairment tested with a 6-item cognitive impairment test.

Participants (n = 501) were aged 66 ± 11 (mean ± SD) years, and their mean duration of DM was 14 ± 10 years. In adjusted models, near (P = 0.016) but not distance (P = 0.984) vision impairment was associated with cognitive impairment. Persons with near vision impairment were almost 4 times more likely to have cognitive impairment (odds ratio 3.90; 95% confidence interval, 1.31-12.56; P = 0.023), after adjusting for age, sex, and other covariables.

Our findings suggest common risk factors and pathways may exist between near vision impairment and cognitive dysfunction in patients with type 2 DM. Future studies need to further assess this link.