Familial correlation of retinal vascular caliber in Singapore Chinese

Our study aimed to explore the heritability of retinal vascular caliber among Singapore Chinese families.

In the Strabismus, Amblyopia, and Refractive Error Study in Singaporean Chinese Preschoolers (STARS) family study conducted from 2008 to 2010, a total of 727 participants (304 parent-child pairs, 83 sibling pairs, and 87 spouse pairs) were included in the analysis. According to standardized protocols, retinal photography, blood pressure measurements, anthropometric measurements, and interviews were performed at clinic. Retinal vascular caliber was assessed by a computer-assisted imaging program (IVAN). Familial correlation of retinal vascular caliber among family pairs was calculated by the FCOR procedure with S.A.G.E. computer software program package and heritability was double the value of the familial correlation.

Mean age was 8.59 years in 304 children and 39.90 years in 423 parents. Mean CRAE and CRVE were 157.09 and 220.80 μm in children, and 150.29 and 220.70 μm in parents, respectively. In multivariate analysis, familial correlation of CRVE was 0.36 (P < 0.001) among parent-child pairs and 0.28 (P < 0.05) among sibling pairs, respectively. Heritability of CRVE was 0.72 and 0.56 among parent-child pairs and sibling pairs, respectively. Family correlation and heritability of CRAE were not significant.

This familial correlation study showed a strong correlation of retinal venular caliber in Singapore Chinese families among parent-child pairs and sibling pairs, independent of age, sex, blood pressure, and BMI. Our findings provide further evidence on substantial heritability of the microvasculature.