Evaluation of peripapillary area and retinal nerve fiber layer thickness using OCT angiography in diabetic retinopathy

Abstract

Background: It has been believed that diabetic retinopathy (DR) is a microvascular disorder. Recent research has linked DR to both neuronal and microvascular processes. The purpose of this research was to use optical coherence tomography angiography (OCTA) to compare the thickness of the peripapillary area and the retinal nerve fiber layer (pRNFL) in DR different stages.Methods: This cross-sectional controlled research was carried out on 40 subjects Cases were subdivided into four equal groups: diabetes mellitus (DM) group (having no DR) non-proliferative DR (NPDR) group, proliferative DR (PDR) group, controls: healthy persons (Healthy eyes with no evidence of diseases affecting macula or optic nerve. Duration of diabetics was not less than 5 years with controlled HbA1c level (5-6%).Results: Significant difference was observed regarding disease duration, Vessel density (VD) between the NPDR, PDR and controls, Thickness of the PRNFL (overall or segmental) between the Diabetes mellitus (DM) groups (DM-NPDR-PDR) and controls. A significant decrease in VD and Thickness of the PRNFL was observed in the optic disc and pRNFL among the DM groups compared to controls. Insignificant difference was observed regarding age, sex, side. A significant negative correlation was observed between disease severity and VD in the pRNFL.Conclusions: As DR worsened, the number of radial peripapillary capillaries in the peripapillary area of the retina dropped. Cases with DM, NPDR, and PDR had thinner PRNFL in the peripapillary area compared to those in the controls.