Abstract
Purpose
This study evaluated a new light-emitting diode (LED-S) photic stimulator and compared skin electroretinogram (ERG) responses obtained to those evoked by the Grass Instrument stimulator (GP-S).
Methods
Two sub-studies were combined to evaluate the difference in responses resulting from the LED-S and GP-S stimuli. The first was a photometry study that matched the LED-S stimuli to the GP-S. In the second study, electroretinograms (ERGs) were recorded under scotopic and photopic conditions using stimuli each stimulator. The stimuli were matched photometrically to measurements obtained from the photometer located 30 cm in front of the stimulators. In addition, the ERG responses were recorded from the LED stimulator when photometrically matched to the GP-S blue stimulus presented through a ganzfeld. The amplitudes and time peaks of the resulting ERG a- and b-waves were then measured and compared using paired T-tests.
Results
Study 1: The LED-S was matched to the GP-S at various intensity settings measured 30 cm away from the stimulator. Measurement through a ganzfeld full-field stimulator (GFFS) demonstrated that the GP-S had a significant hot spot centrally.
Study 2: Photometrically matched ERGs evoked by both stimulators while employing the direct head-on measurements demonstrated multiple similarities. Similarities included component morphology, amplitude and implicit time across the two stimulators, excluding the rod-driven stimulus (GP-S setting employing a blue filter). Differences between the rod-driven ERGs evoked by the GP-S and LED-S while employing head-on photometric measurements were due to the significant difference in intensities between the two stimulators. The GP-S and LED-S evoked similar rod-driven ERG responses when they were matched using the GFFS photometrically matched intensities protocol.
Conclusion
A hand-held stimulator is essential when recording ERG’s in the practice of paediatric visual electrophysiology. The LED-S can match the GP-S stimulus intensities, making it a potential replacement for the GP-S. In addition, the LED-S has uniform intensity across the surface of the device compared to the GP-S, is silent for standard stimuli and can generate prolonged duration stimuli for the recording of on–off ERGs.
Similar content being viewed by others
Change history
10 December 2020
A Correction to this paper has been published: https://doi.org/10.1007/s10633-020-09804-w
References
McCulloch DL, Marmor MF, Brigell MG et al (2015) ISCEV Standard for full-field clinical electroretinography (2015 update). Doc Ophthalmol 130:1–12. https://doi.org/10.1007/s10633-014-9473-7
Fulton AB, Brecelj J, Lorenz B et al (2006) Pediatric clinical visual electrophysiology: a survey of actual practice. Doc Ophthalmol 113:193–204. https://doi.org/10.1007/s10633-006-9029-6
Lapkovska A, Palmowski-Wolfe AM, Todorova MG (2016) Comparing DTL microfiber and neuroline skin electrode in the mini ganzfeld ERG. BMC Ophthalmol 16:137. https://doi.org/10.1186/s12886-016-0311-4
Ji X, McFarlane M, Liu H et al (2019) Hand-held, dilation-free, electroretinography in children under 3 years of age treated with vigabatrin. Doc Ophthalmol 138:195–203. https://doi.org/10.1007/s10633-019-09684-9
Kriss A (1994) Skin ERGs: their effectiveness in paediatric visual assessment, confounding factors, and comparison with ERGs recorded using various types of corneal electrode. Int J Psychophysiol 16:137–146. https://doi.org/10.1016/0167-8760(89)90040-8
Bickford RG, Daly D, Keith HM (1953) Convulsive effects of light stimulation in children. AMA Am J Dis Child 86:170–183. https://doi.org/10.1001/archpedi.1953.02050080179005
Shaw NA (1992) Auditory potentials elicited by the Grass photic stimulator in the rat. Physiol Behav 52:401–403. https://doi.org/10.1016/0031-9384(92)90292-A
Herr DW, Vo KT, King D, Boyes WK (1996) Possible confounding effects of strobe “clicks” on flash evoked potentials in rats. Physiol Behav 59:325–340. https://doi.org/10.1016/0031-9384(95)02133-7
Lucchese F, Mecacci L (1999) Visual evoked potentials and heart rate during white noise stimulation. Int J Neurosci 97:109–114. https://doi.org/10.3109/00207459908994305
Meredith SP, Reddy MA, Allen LE et al (2004) Full-field ERG responses recorded with skin electrodes in paediatric patients with retinal dystrophy. Doc Ophthalmol 109:57–66. https://doi.org/10.1007/s10633-004-1752-2
Yamashita T, Miki A, Tabuchi A et al (2017) A novel method to reduce noise in electroretinography using skin electrodes: a study of noise level, inter-session variability, and reproducibility. Int Ophthalmol 37:317–324. https://doi.org/10.1007/s10792-016-0240-5
Bach M, Brigell M, Chan H et al (2020) Calibration Committee Guidelines ISCEV guidelines for measurement and calibration of stimulus and recording parameters used in clinical electrophysiology of vision, 2020 edition
Hobby AE, Kozareva D, Yonova-Doing E et al (2018) Effect of varying skin surface electrode position on electroretinogram responses recorded using a handheld stimulating and recording system. Doc Ophthalmol 137:79–86. https://doi.org/10.1007/s10633-018-9652-z
Hamilton R, Al Abdlseaed A, Healey J et al (2015) Multi-centre variability of ISCEV standard ERGs in two normal adults. Doc Ophthalmol 130:83–101. https://doi.org/10.1007/s10633-014-9471-9
Acknowledgements
The authors would like to acknowledge the UPMC Children’s Hospital ‘Owl Electrophysiology Unit’ technologists in their assistance in this project.
Funding
No funding was received by any of the authors in support of this work.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
All authors certify that they have no affiliations with or involvement in any organisation or entity with any financial interest (such as honoraria; educational grants; participation in speakers’ bureaus; membership, employment, consultancies, stock ownership or other equity interest; and expert testimony or patent-licensing arrangements) or non-financial interest (such as personal or professional relationships, affiliations, knowledge or beliefs) in the subject matter or materials discussed in this manuscript.
Human and animal rights
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 Declaration of Helsinki and its later amendments or comparable ethical standards. This article does not contain any studies with animals.
Informed consent
This was registered with the University of Pittsburgh’s Medical Centre. All human subjects were adult volunteers from the Department of Ophthalmology, and informed consent was given.
Additional information
Publisher's Note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
About this article
Cite this article
Liasis, A., Gruszewski, J., Toro, J. et al. A comparison of the Grass strobe and new LED photic stimulator for paediatric electroretinogram recordings. Doc Ophthalmol 142, 185–193 (2021). https://doi.org/10.1007/s10633-020-09793-w
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10633-020-09793-w