Evaluating the Influence of Long Term Glycemic Control on Multifocal Electroretinography in Type 2 Diabetic Patients without Retinopathy

INTRODUCTION: We aimed to demonstrate probable neuronal benefits derived from glycemic control in diabetic patients without diabetic retinopathy (DRP) by using multifocal electroretinography (mfERG). METHODS: Forty patients with HbA1c level >8% were included in this study. Baseline mfERG measurement (first kernel order) of patients were done. The study group consisted of patients existed 1 unit decrease in HbA1c relative to baseline and the control group consisted of patients with an insufficient decrease (n=16). The control mfERG measurements of the study group were done after HbA1c decrease is obtained (mean 13.6 months) and in the first year follow-up in the control group. RESULTS: Baseline HbA1c level was 8.7±0.6 in the study group and 8.4±0.5 in the control group and the levels were 7.5±0.5 and 8.35±0.4 respectively after glycemic control. Decrease of HbA1c levels in the study group was significant. Comparing baseline and follow up measurements the difference between P1 and N1 wave amplitude and implicit time values weren’t statistically significant in the study group in which glycemic control was good relative to baseline. DISCUSSION AND CONCLUSION: We have determined no significant changes in mfERG parameters after approximately 1 year follow up in both good and insufficient glycemic control groups. The reasons for this could be the progression of retinopathy in diabetic patients despite glycemic control or inadequacy of first kernel orders in revealing functions of inner retina layers.