Relationship Between Visual Impairment, Age-Related Eye Diseases and Cognitive Function
To describe the associations of visual impairment and major age-related eye diseases with cognitive function in an older Asian population, researchers conducted this population-based, cross-sectional study of 1,179 participants aged 60 to 80 years from the Singapore Malay Eye study.
They measured visual acuity using the logMAR vision chart and graded cataract and age-related macular degeneration using the Wisconsin Cataract Grading System and the Wisconsin Age-Related Maculopathy Grading System, respectively. Glaucoma was diagnosed using the International Society Geographical and Epidemiological Ophthalmology criteria and diabetic retinopathy was graded using the modified Airlie House classification system. Additionally, cognitive dysfunction was defined as a locally validated Abbreviated Mental Test using education-based cutoff scores.
After adjusting for age, sex, education level, income, and type of housing, the researchers found that persons with visual impairment before refractive correction (odds ratio [OR]=2.59; 95% CI, 1.89–3.56) or after refractive correction (OR=1.96; 95% CI, 1.27–3.02) and those with visual impairment due to cataract (OR=2.75; 95% CI, 1.25–5.63) were more likely to have cognitive dysfunction. They reported that only moderate to severe diabetic retinopathy was independently associated with cognitive dysfunction (OR=5.57; 95% CI, 1.56–19.91) after controlling for concurrent age-related eye diseases. They observed no significant independent associations between cataract, age-related macular degeneration, or glaucoma and cognitive dysfunction.
In conclusion, older persons with visual impairment, particularly those with visual impairment due to cataract, were more likely to have cognitive dysfunction. Furthermore, among the major age-related eye diseases, only diabetic retinopathy was associated with cognitive dysfunction.