Characteristics Analysis of Multifocal Electroretinogram in Non-proliferative Diabetic Retinopathy

Abstract Purpose To investigate multifocal electroretinogram (mfERG) changes in non-proliferative diabetic retinopathy (NPDR) patients compared to normal people, and to clarify the differences in changes across various regions of the retina. Methods We selected 18 healthy individuals (22 eyes) and 26 NPDR patients (45 eyes), using the RETscan device for mfERG examination. We analyzed mfERG results for amplitude density and latency of P1 and N1 waves in five rings and four quadrants centered on the fovea. Results In the normal group, mfERG amplitude density decreased from the fovea outward, with significant differences between rings (P < 0.05). The NPDR group showed reduced amplitude density and longer latencies compared to the normal group, particularly in rings 1–2 for P1 wave amplitude density and in all rings for N1 and P1 wave latencies (P < 0.05). In quadrant analysis, the NPDR group had greater P1 amplitude density in the superonasal quadrant and shorter N1 latency in the superotemporal quadrant compared to other areas (P < 0.05). However, in normal individuals, we did not find any differences in retinal function among 4 quadrants. Conclusions Both normal and NPDR individuals show a decline in retinal nerve function from the foveal center to the periphery. Retinal function in normals is affected by age, but not in NPDR patients, which only correlates with BCVA. NPDR patients exhibit early and severe damage to nerve cells near the fovea, with the inferotemporal retina being more susceptible than other regions.