Reduced contrast sensitivity among older women is associated with increased risk of cognitive impairment

ABSTRACT

Objective: Several cross-sectional studies have reported an association between visual contrast sensitivity (a functional measure of low contrast vision) and poor cognitive performance or dementia, but no studies have investigated this association prospectively in a population based cohort with final adjudication of mild cognitive impairment (MCI)/dementia.

Methods: In a prospective, community-based study of aging women (Study of Osteoporotic Fractures), we analyzed whether visual contrast sensitivity was associated with increased risk of MCI or dementia and/or worse performance on various cognitive tests assessed 10 years later. Contrast sensitivity was assessed at baseline in each eye using a VISTECH VCTS 6500 wall chart. MCI/dementia was adjudicated by an expert panel. Multivariable logistic and linear regression models were analyzed.

Results: Of 1,352 White (88.2%) and African-American (11.8%) women with a mean age of 77.7 years (SD 3.3), 536 (39.6%) went on to develop MCI/dementia over 10 years. MCI/Dementia risk was more than doubled (OR 2.16, 95% CI 1.58 to 2.96) in women with the lowest quartile of contrast sensitivity compared to highest (p<0.0001 for the linear trend). Reduced baseline contrast sensitivity was also associated with lower performance on several cognitive measures assessed 10 years later.

Interpretation: Among older women, reduced contrast sensitivity is associated with a greater risk of MCI/dementia. These findings suggest that visual system neurodegeneration or dysfunction may parallel or precede dementia-related cortical or subcortical degeneration, and that contrast sensitivity testing may be useful in identifying aging adults at high risk for dementia. This article is protected by copyright. All rights reserved.

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