Cognitive impairment · Retina · Microvasculature · Fractal dimension · Cognition

Background: Retinal microvascular network changes have been found in patients with age-related brain diseases such as stroke and dementia including Alzheimer’s disease. We examine whether retinal microvascular network changes are also present in preclinical stages of de-mentia. Methods: This is a cross-sectional study of 300 Chinese participants (age: ≥ 60 years) from the ongoing Epidemiology of Dementia in Singapore study who underwent detailed clinical examinations including retinal photography, brain imaging and neuropsychological testing. Retinal vascular parameters were assessed from optic disc-centered photographs us-ing a semiautomated program. A comprehensive neuropsychological battery was adminis-tered, and cognitive function was summarized as composite and domain-specific Z-scores. Cognitive impairment no dementia (CIND) and dementia were diagnosed according to stan-dard diagnostic criteria. Results: Among 268 eligible nondemented participants, 78 subjects were categorized as CIND-mild and 69 as CIND-moderate. In multivariable adjusted models, reduced retinal arteriolar and venular fractal dimensions were associated with an increased risk of CIND-mild and CIND-moderate. Reduced fractal dimensions were associated wit