Assessment of Accuracy of Optical Coherence Tomography Angiography in Evaluation of Foveal Avascular Zone and Perifoveal Intercapillary Area in Ischemic Diabetic Maculopathy as Compared to Fluorescein Angiography

Abstract

lindness is one of the most feared complications of diabetes but also one of the most preventable. Enlargement of the FAZ observed on fundus angiography of the diabetic eye may indicate a poor prognostic visual outcome. Fluorescein angiography (FA), the gold standard for evaluating the retinal vasculature, shows both morphologic and functional changes in the blood vessels in DR. It is invasive test, provide two-dimensional image sets and localization of the depth of the lesion and size delineation of neovascularization can be difficult due to dye leakage and poor stereopsis. Another limitation is that the dyes pose risks ranging from nausea to allergic reactions, including anaphylaxis in rare instances. There for a rapid non-invasive technique to visualize retinal and choroidal vessels would be beneficial. Optical coherence tomography angiography (OCTA) is a new non-invasive imaging technique, without the use of dye, that employs motion contrast imaging to high-resolution volumetric blood flow information generating angiographic images in a matter of seconds. Through our work on 25 eyes of 25 patients with IDM to assess accuracy of OCTA in evaluating the changes in FAZ and perifoveal intercapillary area in IDM, we found that OCTA had more delineated and smaller FAZs with more correlation to VA than those in FA. In addition to its ability to detect 95% of microaneurysms detected by FA. Further researches on larger numbers would confirm these facts.