Distinguishing Diabetic Macular Edema From Capillary Nonperfusion Using Optical Coherence Tomography Angiography

BACKGROUND AND OBJECTIVE: To describe the appearance of diabetic macular edema (DME) using optical coherence tomography angiography (OCTA) and distinguish it from capillary nonperfusion. PATIENTS AND METHODS: Patients with DME were recruited for OCTA imaging. Eyes with confounding retinal diseases were excluded. Using 3 mm x 3 mm OCT angiograms segmented into the superficial and deep inner retinal vascular plexuses, two graders described the appearance of DME and confirmed the diagnosis with structural OCT and fluorescein angiography. RESULTS: DME was evaluated in 17 eyes of 12 patients. The cystoid spaces in DME appeared completely devoid of flow on the OCT angiograms and were oblong in shape with smooth borders that did not follow the distribution of surrounding capillaries, whereas areas of capillary nonperfusion were a greyer hue and had irregular borders. CONCLUSIONS: The cystoid spaces in DME can be differentiated from capillary nonperfusion using OCTA. OCTA may help to guide treatment decisions in the future.