A measured approach may be advisable when dealing with diabetic macular edema, according to a recent trial published in JAMA.
The study, co-authored by Lee Jampol, MD, the Louis Feinberg, MD, Professor of Ophthalmology, found that waiting to start injection treatments until patients began to experience vision loss had similar outcomes when compared to starting injection treatments as soon as the condition was diagnosed. The injections are time consuming, costly and can carry the risk of harmful side effects, so waiting until the treatment is necessary has advantages for both the patient and providers, the authors said.
Diabetic macular edema (DME), an accumulation of fluid in the retina from leaking blood vessels, is a major cause of visual acuity loss worldwide. Until recent years, the standard treatment had been laser photocoagulation: sealing off leaky blood vessels with a laser.
However, over the past decade, a new therapy has emerged: anti-vascular endothelial growth factor (VEGF) injections. VEGF is a protein that stimulates leakage from blood vessels, so blocking the protein can help reduce edema, or swelling of the retina.
Treatment today has largely transitioned to the injections, according to the authors, but many patients have good vision despite edema. Previous studies have shown that many have vision of 20/25 or better, and no studies have examined if injections improve long-term outcomes in this population.
In the current study, 702 patients with DME were randomly assigned to observation, laser photocoagulation or an anti-VEGF injection treatment, aflibercept. If patients in the observation or photocoagulation groups experienced significant vision loss — defined as losing the ability to identify at least one line on a standard eye chart — they were switched to the injection treatment.
After two years, the investigators found no significant difference between earlier initiation of injections versus only resorting to the injection treatment if visual acuity worsened. In total, up to three-quarters of eyes in the study never required the injection treatment.
Each aflibercept injection has an average Medicare cost of $1,850, according to the study, and all eye injections carry a risk of infection or inflammation, so avoiding injections if possible is preferred.
“Reducing anti-VEGF treatments in these eyes while maintaining good vision has clinical and economic advantages for patients and public health,” the authors wrote.
In addition, eyes in the laser photocoagulation group had fewer injections compared to the observation group, indicating some protective benefit. However, the study was not designed to compare laser and observation, the authors cautioned.
Research reported in this publication was supported by the National Eye Institute and the National Institute of Diabetes and Digestive and Kidney Diseases under award numbers UG1EY014231 and UG1EY023207. Regeneron provided aflibercept for the study and funds to the DRCR Retina Network to defray the study’s clinical site costs.
