Anti-VEGF Therapy Worthwhile Even When Diabetic Macular Edema Persists

By Larry Hand

January 28, 2016

NEW YORK (Reuters Health) - In patients with persistent diabetic macular edema (DME), there may be long-term benefits to be gained from continuing with anti-vascular endothelial growth factor (anti-VEGF) therapy, according to a post hoc analysis of a Diabetic Retinopathy Clinical Research (DRCR) Network trial.

"This DRCR Network post hoc analysis suggests that even when DME persists for six months after six injections, many eyes (approximately 60% in this study) may have resolution of edema by three years with little visual acuity deterioration in most cases," principal investigator Adam R. Glassman of Jaeb Center for Health Results, Tampa, Florida, told Reuters Health by email.

"The implications are that continued treatment with anti-VEGF beyond just three injections still may have advantages to treating DME even if treatment initially does not cause resolution of the edema," he said.

The original study, reported in 2010 (http://1.usa.gov/1WAFqSR), involved 854 study eyes in 691 participants. The current analysis focused on 117 eyes with persistent macular thickening through 24 weeks despite at least four intravitreous ranibizumab injections.

The researchers evaluated optical coherence tomography (OCT) and best-corrected visual acuity changes between 24 weeks and three years.

"Eyes with persistent DME through 24 weeks were considered to have chronic persistent DME until they achieved a central subfield thickness less than 250 um and 10% or greater reduction relative to the 24-week study visit on at least two consecutive study visits subsequent to the 24-week visit," the authors wrote.

The probability of chronic persistent DME declined from 100% at 32 weeks to 81.1% at one year, 55.8% at two years, and 40.1% at three years, the authors reported online January 7 in JAMA Ophthalmology.

Visual acuity improved by a mean of seven letters in eyes with persistent chronic DME and by 17 letters in eyes without persistent chronic DME through three years. Seventeen of 40 eyes with chronic persistent DME at three years gained 10 letters or more from 24 weeks, while five eyes lost 10 or more letters.

"In this post hoc analysis of a randomized clinical trial, 40% of eyes with persistent DME at 24 weeks after initiating treatment with ranibizumab had chronic persistent DME through three years, and vision outcomes were only slightly worse than the 60% in which DME did not persist," the researchers wrote. Vision loss of two lines or greater was uncommon at three years, despite chronic persistent DME in some eyes.

"Surveys have suggested that some doctors treat with just a few injections, for example, no more than three, before deciding to consider alternative treatment options," Glassman told Reuters Health. "Most of the cases in the DRCR Network received at least six injections for persistent edema before anti-VEGF was withheld for stability, and then often resumed only if DME recurred or worsened when treatment was withheld."

Dr. Rejendra S. Apte, an ophthalmologist at the Washington University School of Medicine, St. Louis, Missouri, who wrote an invited commentary, told Reuters Health by phone, "What's really nice to know is when you follow these patients with chronic persistent diabetic macular edema, you can see that over a three-year period, they do fairly well."

"You can counsel patients now that it's good to be treated. Even if you're one of those patients who has continued swelling, we can tell you now that you have a good chance your outcome is still likely better than not getting treated - and this is information we didn't have," he said.

Long term, he added, as the burden of diabetes continues to grow heavier, "what this study does is it reassures us to a certain level that those patients who develop this blinding complication, with continued and chronic treatments we currently have - and these are only going to get better - that we can at least have continually improving tools to prevent blindness."

The National Eye Institute and the National Institute of Diabetes and Digestive and Kidney Diseases supported this research.

SOURCE: http://bit.ly/1PkWyMV

JAMA Ophthalmol 2016.

processing....