Reference ranges of light-adapted full-field electroretinogram and associated factors in a large cohort of healthy school-aged children and adolescents

Purpose This study aimed to establish a reference data set of light-adapted full-field electroretinograms (ffERG) of healthy primary and secondary schoolchildren and investigate the relationship among refraction, ocular biometry, and ffERG. Methods Healthy children aged between 6 and 17 years were recruited. Cycloplegic spherical equivalent refraction (SER), axial length (AL) and keratometry (K) measurements were performed. Standardized ffERGs, including light-adapted flash and 30-Hz flicker, were measured using a portable device with skin electrodes. The percentiles of peak time and amplitude of a- and b-waves and 30-Hz flicker of ffERG waveform were reported, and their relationships with age, SER, AL, K were investigated. Results Among the 445 participants (45.4% female), the SER (mean +/- standard deviation) was - 0.72 +/- 2.06 D and AL was 23.56 +/- 1.15 mm. The 90% confidence interval (CI) of 5th reference limit of amplitudes of a- and b-wave were 5.0-5.8 mu V and 15.0-17.6 mu V, while 95th reference limit of peak times were 13.2-13.4 ms and 29.8-30.0 ms, respectively. The amplitude and peak time of the 30-Hz flicker waveform were 21.5-23.9 mu V and 26.0-26.2 ms, respectively. In general, more myopic SER, and longer AL were associated with delayed and reduced ffERG waveforms. Older age and male sex were weakly correlated with ffERGs with minimal clinical significance. Conclusions A reference data set of light-adapted ffERG in children and adolescents was established for clinical and research purposes.