Multifocal Electroretinography in Diabetic Patients without Retinopathy

INTRODUCTION: This study aimed to assess the multifocal electroretinography (mfERG ) findings in diabetic patients without retinopathy according to HbA1c levels and diabetes duration.
METHODS: Sixty two eligible patients with type 2 diabetes mellitus and 30 healthy controls which were matched by age and sex were included in the study. Only the right eye of each patient was analyzed. All of the participants underwent a comprehensive ophthalmic examination, and the mfERG responses which were N1-P1 amplitude, N1 implicit times and P1 implicit times were calculated.
RESULTS: The mfERG N1-P1 amplitude was significantly reduced in diabetic patients compared to controls in inner two rings. There was significantly difference between controls and stable patients’ mfERG P1 implicit times in ring 2. It was found that there was negative correlation trends between diabetes duration and mfERG N1-P1 amplitude, there were negative positive correlation trends between diabetes duration and N1 implicit times and P1 implicit times in all rings. There was statistically significant negative correlation between diabetes duration and N1-P1 amplitude only in ring 5. Also, it was found that there were statistically significant positive correlations between diabetes duration and N1 implicit times in ring 1, 2 and 5. There was significantly correlation between diabetes duration and P1 implicit times only in ring 2.
DISCUSSION AND CONCLUSION: We demonstrated that mfERG N1-P1 amplitude was reduced in inner retinal areas (ring1 and ring 2), and P1 implicit time was delayed only in ring 2 in Turkish diabetic patients without retinopathy. There was statistically significant correlation between diabetes duration and N1-P1 amplitude and N1 implicit times in some retinal areas.