Newly published research led by the Centre for Eye Research Australia (CERA) found a retinal fundus scan can accurately predict a person's risk of stroke, paving the way for non-invasive, routine testing. 

The retina’s potential for stroke risk prediction hasn’t yet been fully explored due to variable study findings and inconsistent use of fundus photography, researchers said. However, its intricate vascular network shares common physical features with those in the brain, making it an ideal candidate for assessing damage from systemic illness, they added.  

Analysing fundus images from 68,753 UK Biobank study participants, researchers measured five retinal vascular architecture characteristics: calibre (length, diameter, ratio), density, ‘twistedness’, branching angle and complexity of the veins and arteries.  

During a follow-up period of 12.5 years, 749 participants (predominantly male, average age 55), had suffered a stroke. In all, 118 retinal vascular measurable indicators were found, of which 29 were significantly associated with first-time stroke risk after adjusting for traditional risk factors. Over half (17) were density indicators, eight fell into the complexity category, three were calibre indicators and one came under the twistedness category. 

Each change in density indicator was associated with an increased stroke risk of 10–19%, while similar changes in calibre indicators were associated with an increased risk of 10–14%. Each decrease in the complexity and twistedness indicators was associated with an increased risk of 10.5–19.5%. 

This retinal ‘vascular fingerprint’, even when combined with just age and sex, was as good as the use of traditional risk factors alone for predicting future stroke risk, the findings showed. 

“Given that age and sex are readily available and retinal parameters can be obtained through routine fundus photography, this model presents a practical and easily implementable approach for incident stroke risk assessment, particularly for primary healthcare and low-resource settings,” researchers concluded.