The Correlation between Changes in Biochemical Parameters and Central Macular Thickness in Patients with Non-Proliferative Diabetic Retinopathy

Abstract This study aimed at evaluating the correlation between changes in Hemoglobin A۱c (HbA۱c) and fasting serum lipids, and Central Macular Thickness (CMT) in patients with Non-Proliferative Diabetic Retinopathy (NPDR). In the current research, both eyes of ۶۸ patients with mild or moderate NPDR, without clinically significant macular edema, were studied. Levels of fasting serum lipids, HbAlc, and CMT were measured during the first visit and at the end of the follow-up period (۳ months). For statistical analysis, CMTs of each eye were studied and the correlation of changes was investigated. Additionally, the direction of changes in CMT for each eye was determined, and whether the changes in both eyes were symmetrical was investigated. Out of ۶۸ patients, ۲۴ were male and ۴۴ were female. The mean CMT of all eyes was ۲۹۰.۰۵ ± ۴۸.۹۰ µm during the first visit and ۲۸۶.۸۰ ± ۳۷.۵۷ µm on the ۳rd month follow-up. The mean HbAlc was ۸.۷۱ ± ۱.۸۲% at first visit to the hospital and the mean HbAlc was ۸.۳۹ ± ۱.۶۵% at the final visit. Although the changes in HbA۱c and CMT during the follow-up period were statistically insignificant, the correlation of these ۲ values was statistically significant (p=۰.۰۱). However, amongst l۳ patients, the CMTs were asymmetrically changed in each eye during the follow-up period. To the best of the author’s knowledge, this was the first study, which indicated a significant correlation in changes of CMT and HbA۱c, even amongst patients with low-grade diabetic retinopathy. Demonstration of asymmetric changes in CMT of each treatment-naive eye of the same patient, during changes in systemic conditions, was another important finding of this study.