Optical Coherence Tomography Angiography Assessment of Deep and Superficial Macular Plexus in Diabetes Mellitus Type II before and after Anti-VEGF Injection

Background: Diabetes mellitus (DM) is a multi-system disease with vision-threatening complications such as diabetic retinopathy (DR) and diabetic macular edema (DME), requiring multi-specialist care. In Egypt and the Middle East, DM prevalence and its complications vary widely, with DR being a leading cause of visual impairment. Imaging tools like optical coherence tomography (OCT) and OCT angiography (OCTA) have become essential in detecting and monitoring DME and DR, offering non-invasive, high-resolution evaluation of retinal microvasculature.
Aim: This study aimed to detect changes in the superficial and deep macular plexus in DME before and after injection of anti-vascular endothelial growth factor (anti-VEGF) using OCTA.
Patients and methods: This prospective interventional trial included 50 eyes of 39 patients with DME who were divided into non-proliferative diabetic retinopathy (NPDR) and proliferative diabetic retinopathy (PDR) groups. Patients with a history of retinal procedures or non-diabetic causes of macular edema were excluded. All participants underwent standardized ophthalmologic examination and data analysis.
Results: The study did not reveal differences in demographics, glycated hemoglobin (HbA1c), intraocular pressure (IOP), DM duration, and the side of the lesion between NPDR and PDR groups. Significant differences in pre- and post-operative best-corrected visual acuity (BCVA) and central macular thickness (CMT) were noted. Vascular density (VD) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP) in parafoveal areas post-operatively was significantly different between the groups, with each group having distinct intra-group changes in visual and anatomical parameters.
Conclusion: The VD of the SCP and DCP of the fovea and parafoveal area, as well as foveal avascular zone (FAZ) size at baseline were good predictor factors for both anatomical and visual improvement after intravitreal ranibizumab injection in eyes with DME. OCTA offers measurements for VD and FAZ size at the macula and could be used to predict the visual prognosis of anti-VEGF treatment in DME.