A prospective, randomized, comparative trial conducted exclusively at Texas Retina, the COED study compared two treatment regimens for diabetic macular edema (DME): a combination of an intravitreal dexamethasone implant (Ozurdex) and aflibercept (Eylea) versus aflibercept alone. The results were recently published in the medical journal Retina.

The COED researchers found that the combination therapy demonstrated similar visual and anatomic outcomes to aflibercept alone at 48 weeks, with a trend toward fewer injections and quicker resolution of DME but higher rates of cataract and intraocular pressure (IOP) elevation.

Current Approaches to Treating DME

Diabetic macular edema (DME) is a vision-threatening complication of diabetes in which fluid accumulates in the macula, the central part of the retina responsible for sharp, detailed vision. It occurs because chronic high blood sugar damages small retinal blood vessels, making them leaky.

First-line treatment consists of intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents, including aflibercept (Eylea). Despite providing visual acuity improvements, these anti-VEGF medications do not always completely resolve DME for patients. As a result, sometimes intravitreal corticosteroids are used to inhibit a broader range of pro-inflammatory and angiogenic factors and help protect the blood-retinal barrier.

About the Intravitreal Dexamethasone Implant

The FDA approved the use of the dexamethasone 0.7 mg intravitreal implant (Ozurdex) for treating diabetic macular edema, posterior segment uveitis, and retinal vein occlusion with macular edema. It uses a solid polymer capsule to enable controlled, sustained drug release, extending treatment intervals and reducing the overall burden compared to standard anti-VEGF injections.

Exploring Combination Therapy for DME

The COED trial was the first prospective trial comparing the combined approach of using the intravitreal dexamethasone implant (Ozurdex) plus aflibercept (Eylea) versus aflibercept alone.

“Our goal was to see if combining these agents could produce superior clinical outcomes in terms of efficacy, safety, and treatment burden,” explains Ashkan Abbey, MD, who serves as Texas Retina’s Director of Clinical Research for Dallas. “As with many retinal diseases, we are constantly looking for ways to extend treatment intervals to lessen the impacts on our patients.”

Because of the higher rates of cataract development and intraocular pressure (IOP) elevation with the combination therapy, the COED trial researchers concluded that aflibercept monotherapy remains an appropriate first-line treatment for DME. However, they stated the combination therapy may be beneficial for certain subgroups of patients, including those with artificial lenses (pseudophakic) or those who cannot adhere to frequent injection schedules.

The following Texas Retina physicians co-authored the COED trial article in Retina along with contributors from Wills Eye Hospital Retina Service, Mid Atlantic Retina, Sidney Kimmel Medical College of Thomas Jefferson University in Philadelphia, Pennsylvania:

Click HERE to access the published article.