Anti-vascular endothelial growth factor (anti-VEGF) therapy is the first-line therapy for physicians who treat patients with diabetic macular edema (DME) and macular edema related to retinal vein occlusion (RVO). The precise changes in the retinal vascular dynamics that occur during therapy have remained undetermined until recently.
The PERMEATE study evaluated how aflibercept (Eylea, Regeneron Pharmaceuticals) affected the peripheral and macular angiographic features, using quantitative ultra-widefield angiography. The study identified significant changes in retinal vascular leakage, retinal ischemia, and microaneurysms in eyes undergoing treatment with intravitreal aflibercept, which previously had not been quantified.
“Multiple phase III studies have demonstrated the impact of anti-VEGF drugs on various disease characteristics, including decreased retinal hemorrhages, improved vascular dynamics such as presence of leakage, potential reduction in ischemia, and changes in the severity of diabetic retinopathy using standard angiography and seven-field photography,” Justis Ehlers, MD, said. “Quantitative and qualitative assessments also have found improved leakage and ischemia resulting from anti-VEGF therapy using these conventional imaging modality.”
Dr. Ehlers noted, however, that a full understanding of the retinal dynamics is not available from previous clinical trials regarding the performance of anti-VEGF therapy because of the limited availability of quantification tools and lack of ultra-widefield imaging data. Utilizing ultra-widefield angiography, a near-panretinal assessment of disease burden and activity is feasible.
Multiple groups are working to improve quantitative assessment, such as correcting the peripheral distortion stereographically, providing automatic leakage segmentation, and assessing retinal vessel permeability, according to Dr. Ehlers, The Norman C. and Donna L. Harbert Endowed Chair for Ophthalmic Research, Cleveland Clinic Lerner College of Medicine, Cleveland.