A fast, non-invasive scan of the retina, the light-sensitive nerve tissue layers at the back of the eye, could one day help doctors identify people who are aging faster and are at higher risk of premature mortality, according to research published online in the British Journal of Ophthalmology.
biological age vs. chronological age
The study, the first of its kind, according to the researchers, could be used as a “retinal age” screening tool to determine the true biological age of our bodies, which may or may not reflect our chronological age; The fact that two people have the same number of years does not mean that they physically deteriorate at the same rate.
A deep learning model, a form of machine learning and artificial intelligence (AI), has now been taught to predict a person’s years of life simply by looking at their retina.
According to the study results, the algorithm managed to predict the retinal age and the real age of almost 47,000 adults between the ages of 40 and 69, all of them belonging to the UK Biobank, with an overall accuracy of 3.5 years.
“People who age fast”
Just over a decade after these retinas were scanned, 1,871 (5%) individuals had died – 321 (17%) of cardiovascular disease; 1,018 (54.5%) of cancer; and 532 (28.5%) from other causes, including dementia—and those with older-looking retinas, “fast-aging people,” were more likely to be in this group.
For example, if the algorithm predicted that a person’s retina was one year older than their actual age, their risk of dying from any cause in the next 11 years increased by 2%. At the same time, the risk of death from a cause other than cardiovascular disease or cancer increased by 3%.
Single “window” of underlying disease processes
“The retina offers a unique and accessible ‘window’ to assess the underlying pathological processes of systemic vascular and neurological diseases that are associated with increased mortality risk,” wrote study author Mingguang He, professor of ophthalmic epidemiology at the University Melbourne and the Australian Eye Research Centre.
Despite the promising correlations, the results are purely observational, meaning that what drives this relationship at the biological level is not yet known.
Growing scientific evidence
However, the results support growing evidence that the retina is highly sensitive to damage from aging. Previous studies have suggested that retinal images contain information on cardiovascular risk factors, chronic kidney disease, and systemic biomarkers, among others.
“Our novel findings have determined that retinal age difference is an independent predictor of increased mortality risk, especially mortality from non-related diseases. [cardiovasculares]/ non-cancerous. These results suggest that retinal age may be a clinically significant biomarker of aging.”
Other existing predictors of biological age are not as accurate – as well as being expensive, time-consuming and invasive – as the retinal age difference appears to be, Science Alert reports. Among these are neuroimaging, the DNA methylation clock, and the transcriptome aging clock.
A) Yes, the new findings, combined with previous research, add weight to “the hypothesis that the retina plays an important role in the aging process and it is sensitive to the accumulated damage of aging that increases the risk of mortality”, explain the authors of the study.
(With information from DW)
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