medwireNews: Changes in the structure and pattern of the retinal vasculature are an early indicator of diabetic retinopathy, and improve the ability of established risk factors to predict which patients will develop it, say researchers.
“Our findings support the concept that computer software assessment of the retinal vasculature in fundus photographs may provide a means to risk stratify individuals at risk of diabetic retinopathy,” they write in Diabetologia.
Tien Yin Wong (Singapore National Eye Centre) and team found that arteriolar tortuosity, venular branching angle, venular branching coefficient, arteriolar fractal dimension, and arteriolar calibre were associated with one or more retinopathy outcomes after accounting for traditional risk factors including blood pressure, glycated hemoglobin, and diabetes duration.
The researchers note that these traditional risk factors do not fully account for patients’ likelihood of developing retinopathy. Receiver operating characteristic curve analysis showed that, when added to traditional risk factors, the retinal variables improved the discrimination between people who did and did not develop diabetic retinopathy over 6 years of follow-up by 9% for any retinopathy and 5% for referable retinopathy.
The retinopathy incidence rates among patients free of it at baseline were 19.2% for any retinopathy and 7.6% for referable retinopathy. The 427 patients studied were those with diabetes identified from among participants of the population-based Singapore Malay Eye Study (SiMES).
The retinal vascular variables also improved risk stratification, with their addition resulting in increases in the net reclassification index of 18.8% for any retinopathy and 20.7% for referable retinopathy, indicating that more patients were being appropriately classified (as either higher or lower risk).
“Currently, individuals with diabetes are in many countries recommended to undergo annual fundus photography for diabetic retinopathy screening,” says the team.
“Incorporating retinal vascular assessment might thus allow a more ‘personalised approach’ to screening intervals; for example, those with lower risk may need only 2-yearly screening.”
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