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Updated: Apr 15, 2026
Electroretinogram Recording for Infants and Children under Anesthesia to Achieve Optimal Dark Adaptation and International Standards
Published on: September 3, 2020
Comparison between fullfield electroretinography obtained from handheld and tabletop devices in normal subjects
Ramya Sachidanandam1, Vikas Khetan2, Parveen Sen3
1Optometrist, Department of Optometry.
Objective:
To compare full-field electroretinography (ERG) parameters obtained from Ephios handheld and VERIS tabletop ERG devices in normal subjects for interchangeable usability and reliability.
Design:
Comparison study.
Participants:
Comparison of full-field ERG between two devices for 57 normal subjects.
Methods:
ERG was recorded for 57 normal subjects using tabletop device (VERIS 5.2.2X; Electro-Diagnostic Imaging Inc, San Mateo, Calif.) and handheld ERG device (Ephios handheld portable ERG system; ephios ab; Teknikringen, Linkoping, Sweden). Bland-Altman plot was done to measure the agreement between the 2 devices. Intraclass correlation coefficient (ICC) was calculated for amplitudes, implicit times, and b/a ratio to assess the reliability. Coefficient of variation (CV = 100 × [standard deviation/mean]) with 95% CI was calculated to measure the variability between the devices. Wilcoxon sign rank test was used to assess the repeatability of the Ephios handheld device.
Results:
The mean a-wave and b-wave amplitudes of dark-adapted 3.0 ERG for the tabletop were 220.3 ± 52.6 and 471.5 ± 84.3 μV, respectively, whereas the mean a-wave and b-wave amplitudes in the same scotopic setting for the handheld device were 152.6 ± 34.2 and 379.7 ± 75.9 μV, respectively. The values represent mean ± standard deviation. The ICC of b/a ratio was 0.660 between the devices. The amplitudes CV of tabletop and handheld ERG devices ranged from 17.9% to 29.1% and from 22.4% to 30.1%, respectively.
Conclusions:
The pattern of waveform of the Ephios handheld device is similar to the VERIS tabletop device. The ERG parameters showed variability between the 2 devices. Hence Ephios handheld ERG device can be used along with its normative data for measuring ERG. Because of variability, the devices cannot be used interchangeably.
