Newswise — BOSTON – (April 29, 2019) – Newly available results will influence the standard approach for treating diabetic macular edema in patients with good vision, thanks to a study published today in the Journal of the American Medical Association. The study was conducted by the DRCR Retina Network, a multicenter clinical research network funded by the National Eye Institute, part of the National Institutes of Health (NIH).
The study found that people with diabetic macular edema, or abnormal swelling of the central retina, who still have good vision, as measured by standard exam with an eye chart, can safely forego immediate treatment of their macular edema as long as they are closely monitored, and treatment begins promptly if vision worsens.
Diabetic macular edema is the most common cause of vision loss among people with diabetic eye disease in the United States. Diabetes can result in the development of leaky blood vessels in the retina—the light-sensing tissue at the back of eye. Diabetic macular edema is the result of fluid build-up in the central area of the retina, called the macula, which is important for sharp vision. Swelling of the macula can distort vision required for reading and driving.
According to a statement released by the National Eye Institute, the evidence from this study should help physicians and patients navigate a common conundrum in ophthalmology: Treating diabetic macular edema in people who still have good vision too soon may subject them to unnecessary costs and risks associated with treatment. Other patients who get treatment too late might risk losing vision permanently.
“These study results demonstrate that as long as patients are closely monitored and if they are treated promptly should their vision worsen, it is reasonable to begin management with watchful waiting rather than immediate treatment for eyes with diabetic macular edema and good vision,” said DRCR Retina Network Co-Chair, Jennifer K. Sun, MD, MPH, associate professor of ophthalmology, Joslin Diabetes Center, Harvard Medical School.
The trial included 702 participants with diabetic macular edema and 20/25 vision or better, which is considered normal or near normal vision. At the start of the study, participants were randomly assigned to one of the following three management strategies for one of their eyes: 1) inject into the eye the anti-VEGF agent aflibercept (EYLEA®) as frequently as every four weeks, 2) perform laser photocoagulation, or 3) conduct observation of the participants.
During the two-year study, the detection of visual acuity loss prompted aflibercept injections to be given to the people in the laser or observation groups. Aflibercept injections were thus required among 25% of the laser group and 34% of the observation group. Eyes that started aflibercept injections in the laser and observation groups required a similar number of injections overall compared to the group initially assigned to aflibercept.
The researchers checked participants’ visual acuity throughout the study at regular follow-up visits in retina specialty clinics. Researchers measured visual acuity in the laser and observation groups at eight and 16 weeks after study entry, and then every 16 weeks unless their visual acuity worsened.
After two years, the percentage of participants whose study eye met a prespecified threshold for visual acuity loss -- one or more lines on an eye chart -- did not differ among the groups: 16% of the aflibercept group, 17% of the laser group, and 19% in the observation group. The average visual acuity, which was 20/20 at baseline, remained 20/20 in all three groups at two years.
“In the future we hope that new methods will allow us to predict more precisely when and how eyes should be treated to provide the very best visual outcomes for all patients with diabetic macular edema. In the meantime, this study provides reassurance that, on average, eyes managed with careful initial observation can maintain excellent vision over time without the need for immediate treatment,” said Lloyd Paul Aiello, MD, PhD, professor of ophthalmology, Joslin Diabetes Center, Harvard Medical School.
The 91-center clinical trial was funded by NEI grants EY14231, EY23207, and the National Institute of Diabetes and Digestive and Kidney Diseases, which is also part of the NIH. ClinicalTrials.gov Identifier: NCT01909791
For more information about diabetic macular edema visit https://nei.nih.gov/health/macular-edema/fact_sheet
Baker CW, Glassman AR, Beaulieu WT, Antoszyk AN, Browning DJ, Chalam KV, Grover S, Jampol LM, Jhaveri CD, Melia M, Stockdale CR, Martin DF, Sun JK, for the DRCR Retina Network. “Effect of initial management with aflibercept vs laser photocoagulation vs observation on vision loss among patients with diabetic macular edema involving the center of the macula and good visual acuity: A randomized clinical trial”. Published online April 29, 2019, JAMA. DOI10.1001/jama.2019.5790 DOI10.1001/jama.2019.5790
NEI leads the federal government’s research on the visual system and eye diseases. NEI supports basic and clinical science programs to develop sight-saving treatments and address special needs of people with vision loss. For more information, visit https://www.nei.nih.gov.