Correlation of retinal nerve fiber layer and ganglion cell complex thickness with glycosylated hemoglobin in diabetic patients

Abstract

Aim The aim of this study was to correlate the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) thickness with glycosylated hemoglobin (HbA1c) in diabetic patients.Setting and design This is a comparative case series study that was conducted on 58 eyes of 30 diabetic patients attending the Outpatient Clinics of the Ophthalmology Department, Beni-Suef University Hospital, Beni-Suef, Egypt, between June and August 2019.Patients and methods The 30 cases were divided into two equal groups: uncontrolled diabetic group (group 1), with HbA1c more than or equal to 7%, and controlled group (group 2), with HbA1c less than 7%. Both eyes in each patient were scanned using optical coherence tomography, ‘Optovue.’ Blood samples for HbA1c testing were collected as well.Results There was a significant negative correlation between average, superior, inferior, and nasal RNFL quadrant thickness and HbA1c in group 1, which was found with HbA1c level more than 9%. In group 2, there was no statistically significant correlation of HbA1c and all RNFL parameters in both eyes. In addition, in group 1, there was a significant negative correlation of average, superior, and inferior GCC quadrant thickness and a positive correlation of focal loss volume with Hb1Ac level more than 9%. In group 2, the average and inferior GCC thickness showed a positive correlation with HbA1c. Furthermore, focal loss volume and global loss volume were negatively correlated with HbA1c.Conclusion There was a statistically significant correlation between thinning of most of RNFL and GCC quadrants and uncontrolled HbA1c more than 9%.