Affiliations: [a] Department of Psychology, Centre for Research in Human Development>, Concordia University, Montréal, Québec, Canada
| [b] Centre for Research on Brain, Language, and Music, Montréal, Québec, Canada
| [c] Institute of Computational Linguistics, University of Zurich, Zurich, Switzerland
| [d] School of Optometry, Université de Montréal, Montréal, Quebec, Canada
| [e] Lady Davis Institute for Medical Research, Jewish General Hospital, Montréal, Québec, Canada
Correspondence:
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Correspondence to: Dr. Natalie Phillips, Concordia University, Cognition, Aging, and Psychophysiology Laboratory, 7141 Sherbrooke Street West, H4B 1R6 Montreal, Quebec, Canada. Tel.: +1 514 848 2424 /Ext. 2218; E-mail: natalie.phillips@concordia.ca.
Abstract: Background:Visual impairment is associated with deficits in cognitive function and risk for cognitive decline and Alzheimer’s disease (AD). Objective:The purpose of this study was to characterize the degree of visual impairment and explore the association thereof with cortical atrophy in brain regions associated with visual processing in individuals with (or at risk for) AD. Methods:Using the Comprehensive Assessment of Neurodegeneration and Dementia (COMPASS-ND) dataset, we analyzed vision and brain imaging data from three diagnostic groups: individuals with subjective cognitive decline (SCD; N = 35), mild cognitive impairment (MCI; N = 74), and mild AD (N = 30). We used ANCOVAs to determine whether performance on reading acuity and contrast sensitivity tests differed across diagnostic groups. Hierarchical regression analyses were applied to determine whether visual performance predicted gray matter volume for vision-related regions of interest above and beyond group membership. Results:The AD group performed significantly worse on reading acuity (F(2,138) = 4.12, p < 0.01, ω2 = 0.04) compared to the SCD group and on contrast sensitivity (F(2,138) = 7.6, p < 0.01, ω2 = 0.09) compared to the SCD and MCI groups, which did not differ from each other. Visual performance was associated with volume in some vision-related structures beyond clinical diagnosis. Conclusion:Our findings demonstrate poor visual performance in AD and that both group membership and visual performance are predictors of cortical pathology, consistent with the idea that atrophy in visual areas and pathways contributes to the functional vision deficits observed in AD.
