Effect of Visual Impairment on Physical and Cognitive Function in Old Age: Findings of a Population-Based Prospective Cohort Study in Germany

Abstract

Objectives: To examine how visual impairment affects physical and cognitive function in old age.

Design: A longitudinal population-based prospective cohort study.

Setting: General practitioner offices at six study centers in Germany. They were observed every 1.5 years over four waves.

Participants: Individuals aged 77-101 at follow-up Wave 2 (N = 2,394).

Measurements: Physical and cognitive function were assessed using an adapted scale that had been previously developed, and visual impairment was rated on a Likert scale (none, mild, severe or profound).

Results: Adjusting for sociodemographic factors and comorbidity, linear fixed-effects regression showed that the onset of severe visual impairment was associated with a decline in physical function score in the total sample (β = -0.15, P = .01) and in women (β = -.15, P = .03). Moreover, the onset of severe visual impairment was associated with decline in cognitive function score in the total sample (β = -0.38, P < .001) and in women (β = -0.38, P < .001) and men (β = -0.37, P = .001).

Conclusion: Visual impairment affects physical and cognitive function in old age. Interventional strategies to postpone visual impairment may contribute to maintaining physical and cognitive function.

Keywords: cognitive function; longitudinal study; older people; physical function; visual impairment.