Comprehensive Foveal Avascular Zone and Retinal Evaluation with Their Correlation to Visual Acuity and Glycemic Control in Diabetics Without Macular Edema

Abstract

<i>Background: </i>Evaluating Foveal avascular zone by OCTA (Optical Coherence Tomography angiography) in diabetic patients, has a crucial role in early detection of pathophhsiological changes affecting the macular area, and has a pedective value for early retinal neuro degenerative changes. <i>Materials and experiments: Aim</i>: To evaluate dimensions of Foveal Avascular Zone (FAZ) at level of superficial and deep capillary plexuses (SCP/DCP) in patients with different grades of non proliferative diabetic retinopathy without Diabetic Macular Edema (DME) using OCTA. Eighty type II diabetes mellitus patients and 20 healthy control, ecxluding proliferative diabetic retinopathy and DME. Divided to four groups according to ETDRS Classification. All undewent: measurement of glycosylated hemoglobin level, standard Structural OCT for the macula and optic nerve head with OCTA for evaluation of FAZ in both SCP and DCP networks of all eyes using (Heidelberg engineering, OCT spectralis, Germany) (SD-OCT). <i>Results</i>: Mean FAZ in SCP in control group (0.32 ± 0.12) mm² versus (0.44 ± 0.17) mm² in patients` group, while FAZ IN DCP (0.23) mm² ± 0.12 in controls versus (0.34 ± 0.16) mm² in patients. There was a statistically significant wider FAZ in DR patients (P-value 0.003). <i>Conclusion</i>: Enlargement of FAZ in SCP and DCP in patients with moderate to severe NPDR without DME was detected using OCTA, Preceeded by reduction in thickness of ORL and GCC layer. This can be used to monitor the progression of the disease and to evaluate the response to treatment.