In a clinical trial, early treatment with anti-vascular endothelial growth factor (VEGF) injections slowed diabetic retinopathy. However, two years into the four-year study, the early treatment's effect on vision – including changes in visual acuity and vision loss – was similar to standard treatment, which usually begins only after the onset of late disease, according to a news release from the National Institutes of Health (NIH).
The intermediate findings from the DRCR Retina Network (DRCR.net) were published in JAMA Ophthalmology. The study was supported by the National Eye Institute (NEI), a part of the National Institutes of Health.
"While it is possible that preventive injections of anti-VEGF drugs may help protect vision in the longer-term, we saw no effect on vision at two years," said Raj Maturi, MD, Indiana University, Indianapolis, the protocol chair for the study. "These two-year results suggest that close monitoring and routine treatment when complications develop are key to preventing vision loss from diabetic retinopathy."
In this study, participants with non-proliferative diabetic retinopathy were randomly assigned at baseline to receive either injections of Eylea (aflibercept) or a sham injection. They were examined at one, two, and four months, and then every four months for two years, receiving Eylea or sham injection at each visit. The researchers tracked their visual acuity and the severity of their diabetic retinopathy. If disease progressed, regardless of whether they were in the treatment or sham group, participants were given Eylea more frequently as is given in standard practice. If their condition did not improve with additional anti-VEGF treatment, participants could be given treatments such as laser photocoagulation or surgery if necessary.
The study included 328 participants (399 eyes). In two years, the rate of proliferative diabetic retinopathy development was 33% in the control group, compared with 14% in the treatment group. Likewise, the rate of development of diabetic macular edema affecting vision was 15% in the control group, compared with 4% in the treatment group. However, loss of visual acuity was essentially the same between the two groups at two years, suggesting that standard treatment at the appearance of proliferative diabetic retinopathy or diabetic macular edema affecting vision is sufficient to prevent further vision loss at this time point.
