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REGAINING LOST VISION : CHANGING THE STANDARDS OF CARE FOR DIABETIC MACULAR EDEMA Retinal Consultants of Houston at Houston Methodist Hospital is the largest recruiting clinical trial center for retina diseases in the United States and focuses on diabetic retinopathy, age-related macular degeneration and other blinding retinal diseases.
David Brown, MD, an associate member of the Houston Methodist Research Institute and clinical assistant professor, Department of Ophthalmology, helped design and run an international protocol for phase III clinical trials of an anti-vascular endothelial growth factor agent, or VEGF-inhibitor, for the treatment of diabetic macular edema (DME). The VISTA-DME and VIVID-DME studies test the efficacy of aflibercept, a VEGF-inhibitor, currently approved only for the treatment of wet macular edema. Based on results from these trials, aflibercept has now been filed for FDA approval for the treatment of diabetic macular edema. Previously, Retina Consultants of Houston was the lead site for phase II and III clinical trials that led to the approval of the first anti-VEGF agent ranibizumab for the treatment of DME. “Ranibizumab was approved by the FDA for diabetic macular edema, an approval that led to changing the standard of care from laser therapy to ocular injections for a type of blinding disease that is extremely common,” says Dr. Brown. These anti-VEGF agents are injected intravitreally and block the upregulation of VEGF. Together with other growth factors and metabolites in diabetic individuals, VEGF can cause a breakdown of the blood-retinal barrier that allows exudation into the interstitial space. This process results in diabetic macular edema in approximately 30 percent of diabetic patients. While previous laser therapy limited vision loss in patients with DME, very few patients regained lost vision. Now, intravitreal injections of anti-VEGF agents are leading to sustained vision gains in most patients with continued therapy.
“Our clinical trials have led to changing the standard of care from laser therapy to ocular injections with resulting vision gains in patients with vision loss from diabetic eye disease.” David Brown, MD
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Houston Methodist Department of Ophthalmology