Effect of varying skin surface electrode position on electroretinogram responses recorded using a handheld stimulating and recording system

Hobby, Angharad E.; Kozareva, Diana; Yonova-Doing, Ekaterina; Hossain, Ibtesham T.; Katta, Mohamed; Huntjens, Byki; Hammond, Christopher J.; Binns, Alison M.; Mahroo, Omar A.

Abstract

Purpose: A handheld device (the RETeval system, LKC Technologies) aims to increase the ease of electroretinogram (ERG) recording by using specially designed skin electrodes, rather than corneal electrodes. We explored effects of electrode position on response parameters recorded using this device. Methods: Healthy adult twins were recruited from the TwinsUK cohort and underwent recording of light-adapted flicker ERGs (corresponding to international standard stimuli). In Group 1, skin electrodes were placed in a “comfortable” position, which was up to 20mm below the lid margin. For subsequent participants (Group 2), the electrode was positioned 2mm from the lid margin as recommended by the manufacturer. Amplitudes and peak times (averaged from both eyes) were compared between groups after age-matching and inclusion of only one twin per pair. Light-adapted flicker and flash ERGs were recorded for an additional 10 healthy subjects in two consecutive recording sessions: in the test eye, electrode position was varied from 2 to 10–20mm below the lid margin between sessions; in the fellow (control) eye, the electrode was 2mm below the lid margin throughout. Amplitudes and peak times (test eye normalised to control eye) were compared for the two sessions. Results: Including one twin per pair, and age-matching yielded 28 individuals per group. Flicker ERG amplitudes were significantly lower for Group 1 than Group 2 participants (p = 0.0024). However, mean peak times did not differ between groups (p = 0.54). For the subjects in whom electrode position was changed between recording sessions, flash and flicker amplitudes were significantly lower when positioned further from the lid margin (p < 0.005), but peak times were similar (p > 0.5). Conclusions: Moving the skin electrodes further from the lid margin significantly reduces response amplitudes, highlighting the importance of consistent electrode positioning. However, this does not significantly affect peak times. Thus, it may be feasible to adopt a more comfortable position in participants who cannot tolerate the recommended position if analysis is restricted to peak time parameters.

• Journal Article Type: Article
• Acceptance Date: Jul 17, 2018
• Online Publication Date: Jul 25, 2018
• Publication Date: Oct 1, 2018
• Deposit Date: Sep 15, 2022
• Publicly Available Date: Sep 16, 2022
• Journal: Documenta Ophthalmologica
• Print ISSN: 0012-4486
• Electronic ISSN: 1573-2622
• Publisher: Springer Verlag
• Peer Reviewed: Peer Reviewed
• Volume: 137
• Issue: 2
• Pages: 79-86
• DOI: https://doi.org/10.1007/s10633-018-9652-z
• Keywords: Physiology (medical), Sensory Systems, Ophthalmology, Electroretinogram, Retina, Electrode, Retinal function
• Public URL: https://uwe-repository.worktribe.com/output/9987343
• Publisher URL: https://link.springer.com/article/10.1007/s10633-018-9652-z
• Additional Information: Received: 12 February 2018; Accepted: 17 July 2018; First Online: 25 July 2018; : ; : The authors declare that they have no conflict of interest.; : All participants gave informed consent.; : All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards.; : No animals were used in this research.