Diabetic Macular Edema (DME) is the leading cause of visual impairment in patients with diabetic retinopathy.1 In 2010, approximately 20.6 million out of a projected 92.6 million adults with diabetic retinopathy worldwide were estimated to have concurrent DME.2 This global healthcare burden will likely continue to increase at alarming rates, as some models estimate the number of diabetics will double by the year 2030.3
With the Early Treatment Diabetic Retinopathy Study (ETDRS) in the 1980s,4 macular laser photocoagulation became the mainstay of DME management, and it remained the standard of care in the decades that followed. The advent of intravitreal pharmacotherapy agents, primarily driven by the class of vascular endothelial growth factor (VEGF) inhibitors, has since revolutionized how this condition is treated. Validated through the RISE and RIDE phase 3 clinical trials,5 ranibizumab (Lucentis; Genentech, South San Francisco, California, USA) became the first VEGF inhibitor approved by the Food & Drug Administration (FDA) for this indication in 2012.
While off-label, bevacizumab (Avastin; Genentech) has been evaluated through smaller trials, such as the BOLT study.6 Most recently, aflibercept (Eylea; Regeneron, Tarrytown, New York) gained FDA approval to treat DME in July 2014 with the VIVID and VISTA phase 3 clinical trials.7,8
While there is ample evidence supporting the safety and efficacy of the 3 anti-VEGF agents in the management of DME, a head-to-head comparison only recently became available when the Diabetic Retinopathy Clinical Research Network (DRCR) published the 1-year outcomes of its Comparative Effectiveness Study of Intravitreal Aflibercept, Bevacizumab, and Ranibizumab for DME (Protocol T).9 The results demonstrated that when baseline visual acuity (VA) loss was mild (›20/ 40), there was no clinical difference between the 3 medications. However, when the initial acuity loss was more severe (‹20/50), a greater visual benefit was derived from aflibercept.9
Since the FDA approval of aflibercept for DME, and in light of Protocol T’s findings, many retinal specialists are converting eyes from ranibizumab or bevacizumab to aflibercept with the goal of optimizing treatment outcomes, particularly in cases of refractory DME. In the current study, we evaluated the short-term functional and anatomic responses of patients with persistent DME after multiple previous anti-VEGF injections that were converted to aflibercept therapy.
Full Paper: Conversion to Aflibercept After Prior Anti-VEGF Therapy for Persistent Diabetic Macular Edema