The tiny blood vessels in the eyes might hold the key to predicting a person’s risk of developing heart disease and how fast they’re biologically aging, according to researchers at McMaster and the Population Health Research Institute (PHRI) — a joint institute with Hamilton Health Sciences.
The study, published in Sciences Advances on Oct. 24, suggests that retinal scans could one day serve as a non-invasive window into the body’s overall vascular health and biological aging status, offering new opportunities for early detection and intervention.
“By connecting retinal scans, genetics, and blood biomarkers, we have uncovered molecular pathways that help explain how aging affects the vascular system,” says Marie Pigeyre, senior author of the study and associate professor in the Department of Medicine.
“The eye provides a unique, non-invasive view into the body’s circulatory system,” adds Pigeyre, a scientist with PHRI. “Changes in the retinal blood vessels often mirror changes occurring throughout the body’s small vessels.”
To conduct the study, researchers combined retinal scans, genetic data and blood sample analyses from over 74,000 participants across four major cohorts: the Canadian Longitudinal Study on Aging (CLSA), the Genetics of Diabetes Audit and Research Tayside Study (GoDARTS), the UK Biobank(UKBB), and the PHRI Prospective Urban Rural Epidemiological (PURE) study.
They found that people with simpler, less branched blood vessels were at increased risk of cardiovascular diseases and showed signs of biological aging, such as higher inflammation and shorter lifespan.
Currently, assessing age-related diseases like heart disease, stroke and dementia requires multiple tests. The hope is that retinal scans alone could eventually be used as a quick, accessible way to assess aging and cardiovascular risk. But for now, the full picture still requires deeper clinical assessment.
Another important aspect of the study came from reviewing blood biomarkers and genetic data: Researchers uncovered not just associations, but potential biological causes behind changes in the eye’s blood vessels. This helped them identify specific proteins that may drive aging and disease.
Two of the more notable proteins are MMP12 and IgG–Fc receptor IIb — both linked to inflammation and vascular aging. These proteins could be potential targets for future drugs, Pigeyre says.
“Our findings point to potential drug targets for slowing vascular aging, reducing the burden of cardiovascular diseases, and ultimately improving lifespan,” she says.
Blood protein biomarker data was supplied from the Prospective Urban and Rural Epidemiological study, a major international research initiative led by PHRI.
This research was supported by the Canadian Institutes of Health Research, the E.J. Moran Campbell Internal Career Research Award from McMaster University and the Early Career Research Award from Hamilton Health Sciences (HHS). Retinal image analyses of the CLSA were supported by a New Investigator Fund from HHS.