Association between Diabetic Macular Edema and Capillary Non Perfusion; An Optical Coherence Tomography Angiography Study

Aims: The aim is to use of OCTA to describe the retinal structural damages observed in DME and the relationship between the edema and the capillary non perfusion and to quantify VD and the FAZ area.

Study Design: prospective, cross sectional, observational study

Place and Duration of Study: University Hospitals in the period between March 2018 to March 2020.

Methodology: OCTA images were obtained using the AngioVue (Optovue Inc., CA, USA). For quantitative analysis of the VD and the FAZ area with the help of the manufacturer’s automated software.

Results: The study included included 160 eyes of 135 diabetic patients, 61 (45%) females and 74 (55%) males and 20 eyes from 20 age-matched healthy individuals (12 males and 8 females). A significantly worse visual acuity was found in diabetic eyes with CME (mean (x̅) ± SD LogMAR 0.61 ± 0.33), than NPDR eyes without macular edema (0.25 ± 0.19), and controls (Mean ± SD LogMAR 0.02 ± 0.05),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 AngioAnalytics parameters (vessel density and non-flow area) aided in the objective quantification of macular perfusion and accurate measurement of the FAZ area in diabetic eyes with and without macular edema. Both parameters were significantly correlated with visual function in treatment-naive diabetic eyes with macular edema.