Vessel Density as a Biomarker for Progression of Diabetic Macular Edema: An Optical Coherence Tomography Angiography Study

Abstract Background: Diabetic macular edema development and progression is important prognostic factor for determining the final visual outcome and quality of life for each diabetic patient. OCTA vessel density is quantitative parameter that could be used to quantify and measure macular diabetic edema and ischemia. Our study used the VD values to follow-up these edema changes along the diabetic retinopathy course Aim of Study: The aim is to use of optical coherence tomography angiography to quantify vessel density throughout the different stages of diabetic macular edema progression. Material and Methods: OCTA images were obtained using the AngioVue (Optovue Inc., CA, USA). For quantitative analysis of the VD with the help of the manufacturer's auto-mated software. Study Design: Prospective, cross sectional, observational study. Place and Duration of Study: University Hospitals in the period between March 2017 to March 2019. Results: The study included 160 eyes of 135 diabetic patients, 61 (45%) females and 74 (55%) males. The values of VD of the SCP were significantly affected more than the DCP very early in the diabetic course (No DR stage) (p=0.040). Moving one stage more in the disease (mild to moderate NPDR with no edema stage) the deep layer got significantly more affected than the superficial layer (p=0.038). In the more advanced stages of the disease and as the macular edema develop and progress (spongy edema and CME) the two plexuses showed decreased VD values nearly to the same degree with the deep plexus affected slightly more (low VD values) than the superficial plexus. Conclusion: Using the OCTA machine with AngioAna-lytics parameters (vessel density) aided in the objective quantification of macular perfusion in diabetic eyes with and without macular edema.