Study of peripapillary retinal nerve fiber layer thickness in patients of type 2 diabetes mellitus and its correlation with glycemic control

Abstract

Context: The retina of diabetic patients undergoes neurodegenerative changes, in addition to the vascular changes. Aims: The aim of this study is to evaluate the peripapillary retinal nerve fiber layer (RNFL) thickness in type 2 diabetes mellitus (DM) patients compared to healthy controls, using optical coherence tomography (OCT) and to correlate it with glycemic control. Settings and Design: Prospective study. Subjects and Methods: A total of 90 patients were enrolled in the study. The study group included 120 eyes of 60 type 2 DM patients. Sixty eyes of 30 healthy participants served as the control group. All patients underwent an OCT scan for peripapillary RNFL thickness measurement. Metabolic control of DM was assessed using glycosylated hemoglobin (HbA1c). Statistical Analysis Used: Independent sample t-test was used for normally distributed variables. Pearson's correlation analysis was used to assess the correlation between HbA1c and RNFL thickness. Results: Right eye RNFL thickness was thinner in diabetic patients than controls, with a statistically significant P value (P = 0.002) in the superior quadrant and inferior quadrant (P = 0.019). The average, superior, and inferior RNFL thickness in the left eye was significantly thinner in diabetic patients as compared to controls (P