Window to the brain: Can retinopathy be used to assess cognitive function

OBJECTIVE: Retinopathy status as a screening method to predict cognitive health is limited. The objective of this study was to examine the association between retinopathy and lowered cognitive performance in a Canadian First Nations population. METHODS: Eligible individuals were assessed by the Clock Drawing Test (CDT) and the Trail Making Test Parts A and B, which were combined into an executive function score (TMT-exec). Digital fundus photographs were taken for both eyes to assess retinopathy. Anthropometric, vascular and metabolic risk factors were assessed by interview, clinical examinations and blood tests. Carotid atherosclerosis was assessed by Doppler ultrasonography. RESULTS: Retinopathy was detected in 7.1% of the population. Individuals classified as having a previous history of cardiovascular disease, insulin resistance and diabetes were more likely to have retinopathy. No other cardiovascular risk factors were associated. In unadjusted analysis, there were no associations between retinopathy and lowered cognitive performance (CDT, odds ratio [OR]: 0.86, 95% confidence interval [CI]: 0.30–2.53; TMT-exec, OR: 1.79, 95% CI: 0.60–5.33). Multivariable adjusted analysis also showed no associations, although sample size may be limiting. CONCLUSIONS: Retinopathy was not associated with lowered cognitive performance. Associations for microvascular risk factors suggest a panel of cognitive tests is needed for future studies.