Abstract
Purpose:
To study the correlation between visual acuity, refraction and cognitive state in an elderly population, with no known dementia or Alzheimer's disease.
Methods:
A cross sectional study was conducted, comprising of 200 subjects age 75 and older from adult day care centers. Near visual acuity was tested using the Jaeger chart and refraction was examined by a portable auto-refractometer. Cognitive function was evaluated with the mini-mental state examination (MMSE). The eye with better visual acuity and no cataract or refractive surgery was used for analysis. Patients that underwent cataract or refractive surgery in both eyes were excluded. Correlation tests were used to find association between visual acuity, refraction, wearing eyeglasses for near or far vision and cognitive functions.
Results:
One hundred and ninety five subjects (mean age 81.6 ± 5.1 years, 70.3% females) fulfilled the inclusion criteria and comprised the study population. The mean period of education was 9.2 ± 4.6 years (range 0-25). Mean Jaeger near visual acuity was J3.3 ± 3.1 (range J1-J16). Mean refractive error was 0.52 ± 2.33 (range +4.625 to -5.625). Eyeglasses for near vision were used by 124 (63.6%) participants and 128 (65.6%) participants used eyeglasses for distance vision. Mean MMSE was 24.9 ± 4.0 points (range 15-30). Good near visual acuity (J3 or lower) was found to be associated with high MMSE score (>24) (OR=3.74, 95% CI=1.86-7.52, p<0.001) and remained significant after adjustment for sex, age and years of education. Wearing eyeglasses for near or far vision were found to be correlated with high MMSE score after adjustment for sex and age (OR=1.95, 95% CI=1.06-3.57, p=0.03, OR=1.94, 95% CI=1.05-3.59, p=0.04, respectively) but did not after adjustment for years of education. A trend was found toward correlation between myopia and better MMSE score (r=-0.12, p=0.09, Pearson's correlation) although it did not remain so after adjusting for sex, age or education.
Conclusions:
Good near visual acuity and wearing eyeglasses for far or near vision seem to be correlated with better cognitive function. The nature of the relationship between visual and cognitive functions and possible causality needs to be further investigated.
Keywords: 414 aging: visual performance •
413 aging •
754 visual acuity