Effect of decreased visual acuity on cortical thickness: A possible risk factor for neurodegeneration

Abstract

AbstractBackgroundCortical thickness is a biomarker for neurodegeneration. Ample evidence supports the idea that decreased sensory stimuli lead to degeneration of relevant central areas in the brain. We hypothesized that decreased visual stimuli might be associated with cortical atrophy in visual processing areas. Therefore, we investigated the association between visual acuity (VA) and cortical thickness in cognitive normal adults.MethodWe retrospectively analyzed the health screening data from the Health Promotion Center at the Samsung Medical Center from 2008 to 2014. In total, 2,810 cognitive normal subjects who checked corrected VA and Brain MRI were identified. The subjects were divided into 3 groups according to the VA of better eye: Group 1 (VA The higher VA value indicates better VA. Using multivariate regression analysis, cortical thickness of Group 1 and 2 were compared with Group 3. We also analyzed linear association between VA and cortical thickness. The analyses were performed after controlling for age, sex, hypertension, diabetes, hyperlipidemia, and intracranial volume.ResultCompared to Group 3, Group 1 showed cortical thinning in the bilateral occipital, lateral temporal, and lateral parietal areas. Compared to Group 3, Group 2 also showed cortical thinning in the bilateral occipital, right lateral temporal, and bilateral lateral parietal areas. Linear association analysis showed that the lower VA was associated with cortical thinning in the bilateral occipital areas.ConclusionOur results showed that cognitive normal individuals with lower VA have cortical thinning in the posterior part of the brain which is responsible for visual processing. This suggest that good VA may have preventive effect for neurodegeneration.