Vision, vision-specific functioning and mobility, and their relationship with clinically assessed cognitive impairment.

BACKGROUND

The relationship between self-reported visual disability and cognitive impairment in older individuals is unclear.

OBJECTIVE

To determine the relationship of vision-specific functioning (VSF), vision-specific mobility (VSM) and visual acuity (VA) with clinically assessed cognitive impairment in the Epidemiology of Dementia in Singapore study.

DESIGN

Cross-sectional.

SETTING

Population-based.

SUBJECTS

Eight hundred and seventy-four adults aged ≥60 years at higher risk of possible cognitive impairment by the Abbreviated Mental Test and progressive forgetfulness question.

METHODS

VSF and VSM were measured using Rasch-transformed continuous scores of two Impact of Vision Impairment questionnaire domains. Cognitive impairment was objectively determined using detailed neuropsychological testing and defined as no cognitive impairment (NCI), mild cognitive impairment-no dementia (CIND), moderate CIND only and moderate CIND or dementia. Associations were assessed using multinomial logistic regression models.

RESULTS

Of the 874 participants (49.0% males, mean age (SD) 65.5 (7.0) years), 277, 281 and 316 had NCI, mild CIND and moderate CIND or dementia, respectively. Compared to NCI, the odds of moderate CIND, and moderate CIND or dementia increased for every SD worsening in VSF (OR: 1.44, 95% CI 1.14-1.82, and OR: 1.52, 95%CI 1.19-1.94, respectively) and VSM (OR: 1.42, 95%CI 1.11-1.81, and OR: 1.50, 95%CI 1.15-1.95). Similarly, the odds of mild CIND (OR: 1.62, 95%CI 1.19-2.22), moderate CIND (OR: 1.93, 95%CI 1.45-2.58), and moderate CIND or dementia (OR: 2.25, 95%CI 1.62-3.11) increased significantly with every SD worsening of VA.

CONCLUSIONS

Our results emphasise the importance of interventions to prevent vision loss and improve quality of life to reduce likelihood of age-related cognitive decline.