Spatial Characteristics of the First-order Kernels of Multifocal Electroretinogram Waveforms with High-rate Sampling and Long-duration Recording

Abstract

Detailed analysis of normal multifocal electroretinogram (mERG) first-order kernels in man. mERGs recorded repeatedly from a well-trained examinee were analyzed with a visual evoked response imaging system (VERIS). Sampling interval and recording duration were set to yield better resolution and lower S/N ratio. Reproducibility was tested in the "all trace" waveform. Focal variation of each of the 103 waveforms and regional variation of grouped waveforms were analyzed. The variation coefficient of the "all traces" waveform was lower for peak latencies than for response densities. Among the 103 focal waveforms, the response density was highest at the macular area and lowest around the optic nerve head. The central ring had the highest response density and the longest peak latency among concentric annular areas. Response density was higher in the upper or nasal retina than in the lower or temporal retina. The area with higher response density demonstrated a tendency to show longer peak latency. mERG response density was highest at the macular area and lowest around the optic nerve head. The N1 and P1 peak latencies were longest at the macular area and the N2 peak latency was longest around the optic nerve head.