Early anti-VEGF treatment of diabetic retinopathy doesn’t improve visual acuity, according to the results of a four-year clinical study which also reinforce earlier findings.
Indiana University School of Medicine’s Dr Raj Maturi, who is the protocol chair for the four-year study, said it indicates that monitoring patients regularly for vision-threatening diabetes complications and treating eyes only as needed is the best approach.
The study from the DRCR Retina Network was funded by the National Eye Institute in the US with results published in the Journal of the American Medical Association (JAMA).
It enrolled 328 participants, with 399 study eyes (some participants had two eyes that met criteria for enrolment in the study; others only had one study-eligible eye).
Researchers evaluated whether treating people with non-proliferative diabetic retinopathy (NPDR) with anti-VEGF drug Eylea (aflibercept) could prevent vision loss.
Anti-VEGF injections were given in 200 eyes at one month after enrolment, two months, and four months, and then every four months over two years. Preventative treatment continued every four months through four years unless NPDR improved to only mild disease.
Sham injections (without drug) were used in 199 eyes over the same period. Any eye that developed a vision-threatening complication, such as macular edema or proliferative diabetic retinopathy (PDR) was treated with additional anti-VEGF injections as necessary.
Two-year results of the study suggested that while preventive treatment reduced the risk of developing diabetic macular edema or PDR, there was no evident benefit to vision. The final, four-year results reinforce the earlier finding, with no statistical difference in either visual acuity or rates of vision loss between the two groups.
Mr Adam Glassman, director of the DRCR Retina Network coordinating centre, said researcher’s expectations were not met.
“We expected early treatment to prevent progression of diabetic retinopathy, but even with preventative injections, about one-third of eyes developed vision-threatening complications,” he said.
Over the four-year study, 34% of eyes receiving preventive treatments showed disease progression, compared with 57% of those in the sham group. On average, those in the preventive group received 11 injections, compared with an average of three in the sham group.
Dr Jennifer Sun, chair of diabetes initiatives for the DRCR Retina Network, said that while the individual risk of complications per injection is low, the risk increases with each additional injection.
“The results of this study indicate that the anatomic benefit from early anti-VEGF treatment does not result in improved visual acuity, and so it may not be worth the risk and inconvenience to the patient of repeat preventive injections for NPDR.”
The study was supported by National Eye Institute and the National Institute of Diabetes and Digestive and Kidney Diseases, with funding through the Special Diabetes Program. Regeneron provided aflibercept for the study and funds to DRCR Retina Network to defray the study’s clinical site costs.
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