Three Different Optical Coherence Tomography Angiography Measurement Methods for Assessing Capillary Density Changes in Diabetic Retinopathy

BACKGROUND AND OBJECTIVE: To compare capillary density (CD) changes assessed by optical coherence tomography angiography (OCTA) during diabetic retinopathy (DR) progression using three previously published methods: binarization, skeletonization, and automated flow density (AFD). PATIENTS AND METHODS: Retrospective study of 98 eyes of 74 patients with diabetes and 18 control eyes imaged using OCTA. The macular CD at each stage of DR was assessed using the three methods and were compared to control eyes. RESULTS: AFD was the only method that detected differences between controls and severe nonproliferative DR eyes. The three methods showed a significant difference in CD between controls and eyes with proliferative DR, except for the fovea area. CONCLUSION: Only one of the three methods allowed for the detection of changes from the normal capillary density as early as at the severe nonproliferative DR stage due to several refinements from the basic technique.