Association of Foveal Avascular Zone Enlargement and Diabetic Retinopathy Progression Using Optical Coherence Tomography Angiography

Purpose: The purpose of this article is to evaluate long-term change of the foveal avascular zone (FAZ) area in diabetic eyes using optical coherence tomography angiography (OCTA) (AngioVue, Avanti OCT, Optovue). Methods: A retrospective chart review was conducted of patients who had undergone OCTA fundus examinations with at least 12 months of follow-up. Eyes with previous laser photocoagulation and antivascular endothelial growth factor treatments were excluded. ImageJ software was used to evaluate the FAZ area in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). Results: Forty eyes were analyzed in this study and divided into 3 groups: healthy controls (13 eyes), diabetic patients without diabetic retinopathy (DR) (14 eyes), and diabetic patients with DR (13 eyes). During the 22 months of follow-up, the FAZ area of eyes with DR in the DCP enlarged from 0.64 ± 0.20 mm2 to 0.70 ± 0.20 mm2 ( P = .021), which was a 10.1% increase from baseline (5.1% per year). No significant changes were observed during the study period for FAZ areas in the DCP of controls and diabetic patients without DR. Enlargement of FAZ in the DCP was significantly greater in eyes with DR progression vs those without progression (19.2% and 1.2%, respectively, P = .013). Conclusions: Our data suggest FAZ enlargement in the DCP is associated with DR progression. Assessment of the FAZ by OCTA might be useful for the evaluation of microcirculation abnormalities in DR and the onset of DR progression.