Fundus pictures of the eye allow for non-invasive inspection of the microvasculature system of the retina which is informative on cardiovascular health. Automated image processing enables the extraction of morphometric properties of this system as quantitative features that can be used for modelling disease risks.
Here we report the results of the largest genome-wide association study (GWAS) of retinal vessel tortuosity conducted to date using data from the UK Biobank (N=63,899). We identified 87 loci associated with this trait (85 of which are novel). The heritability of the trait was h2=0.23 (0.02). We carried out a replication study on a small independent population-based cohort, SKIPOGH (N=436). While the power of this study was too small to replicate individual hits, the effect size estimates correlated significantly between the two studies (Pearson correlation r=0.55, p=4.6E-6). We showed that the alleles associated with retinal vessel tortuosity point to a common genetic architecture of this trait with CVD and related traits.
Our results shed new light on the genetics of cardiovascular risk factors and disease.