Vision and cognition in Alzheimer's disease

Alzheimer's disease (AD) is known to affect visual pathways, but potential concomitant effects on vision and cognitive performance are not well unders tood. We studied 43 individuals with AD of mild severity and 22 individuals without dementia on a battery of tests designed to measure multiple aspect s of basic and higher-order visual perception and cognition. All subjects p erformed on the same visual and cognitive test batteries. The results showe d no differences between groups on tests of static visual acuity, stereoacu ity, dynamic visual acuity or motion direction discrimination. However, ind ividuals with AD performed significantly worse on tests of static spatial c ontrast sensitivity, visual attention, shape-from-motion, color, visuospati al construction and Visual memory. Correlation analyses showed strong relat ionships between visual and cognitive scores. The findings show that AD aff ects several aspects of vision and are compatible with the hypothesis that visual dysfunction in AD may contribute to performance decrements in other cognitive domains. The pattern of involvement indicates that AD affects mul tiple visual neural pathways and regions. It is possible that better unders tanding of vision-related dysfunction could aid diagnosis and interventions to improve functional capacity in patients with dementia. (C) 2000 Elsevie r Science Ltd. All rights reserved.