Optical Coherence Tomography Angiography for Biomarker Indices in Diabetes (Book Chapter)

Optical coherence tomography angiography (OCTA) visualizes the structure and flow of retinal vasculature using motion contrast. Diabetic retinopathy (DR), commonly present in one-third of the patients with diabetes, is a major microvascular complication of diabetes mellitus caused by retinal ischemia and vascular hyperpermeability. Microvasculature changes, such as foveal avascular zone enlargement and decrease in vascular density of the deep capillary plexus, have been identified in diabetic eyes without clinical retinopathy. OCTA of nonproliferative DR shows morphologically well-defined microaneurysms and intraretinal vascular shunts around perfusion dropouts at the deep capillary plexus level. In proliferative DR, OCTA visualizes detailed features and extent ...