Flicker electroretinogram in newborn infants

James V M Hanson; Caroline Weber; Oliver A Pfäffli; Dirk Bassler; Daphne L McCulloch; Christina Gerth-Kahlert

doi:10.1007/s10633-022-09889-5

Flicker electroretinogram in newborn infants

Doc Ophthalmol. 2022 Dec;145(3):175-184. doi: 10.1007/s10633-022-09889-5. Epub 2022 Oct 6.

Authors

James V M Hanson^#¹, Caroline Weber^#², Oliver A Pfäffli³, Dirk Bassler², Daphne L McCulloch⁴, Christina Gerth-Kahlert⁵

Affiliations

¹ Department of Ophthalmology, University Hospital Zurich and University of Zurich, Zurich, Switzerland.
² Department of Neonatology, Newborn Research, University Hospital Zurich and University of Zurich, Zurich, Switzerland.
³ Department of Ophthalmology, Cantonal Hospital Lucerne, Lucerne, Switzerland.
⁴ School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada.
⁵ Department of Ophthalmology, University Hospital Zurich and University of Zurich, Zurich, Switzerland. christina.gerth-kahlert@usz.ch.

^# Contributed equally.

Abstract

Purpose: To develop and validate a flicker electroretinogram (ERG) protocol in term-born neonates as a potential tool for assessing preterm infants at risk of developing retinopathy of prematurity.

Methods: A custom flicker ERG protocol was developed for use with the hand-held RETeval® electrophysiology device. Feasibility of measuring flicker ERG through closed eyelids and without mydriasis was established in a pilot study enabling optimisation of the test protocol. Following this, healthy term-born neonates (gestational age 37-42 weeks) were recruited at the Neonatology clinic of the University Hospital Zurich. Flicker ERG recordings were performed using proprietary disposable skin electrodes during the first four days of life when the infants were sleeping. Flicker stimuli were presented at 28.3 Hz for a stimulus series at 3, 6, 12, 30, and 50 cd·s/m², with two measurements at each stimulus level. Results were analysed offline. Flicker ERG peak times and amplitudes were derived from the averaged measurements per stimulus level for each subject.

Results: 28 term-born neonates were included in the analysis. All infants tolerated the testing procedure well. Flicker ERG recording was achieved in all subjects with reproducible flicker ERG waveforms for 30 and 50 cd·s/m² stimuli. Reproducible ERGs were recorded in the majority of infants for the weaker stimuli (with detectable ERGs in 20/28, 25/28, and 27/28 at 3, 6, and 12 cd·s/m², respectively). Flicker ERG amplitudes increased with increasing stimulus strength, with peak times concurrently decreasing slightly.

Conclusion: Flicker ERG recording is feasible and reliably recorded in sleeping neonates through closed eyelids using skin electrodes and without mydriasis. Flicker ERG amplitude decreases for lower luminance flicker but remains detectable for 3 cd·s/m² flicker in the majority of healthy term-born neonates. These data provide a basis to study retinal function in premature infants using this protocol.

Keywords: Electroretinogram; Flicker ERG; Human neonate; Newborn infant; Retinal development.

MeSH terms

Electroretinography* / methods
Humans
Infant
Infant, Newborn
Infant, Premature
Mydriasis*
Photic Stimulation / methods
Pilot Projects
Retina