Hand-held, dilation-free, electroretinography in children under 3 years of age treated with vigabatrin

  • Xiang Ji
  • Michelle McFarlane
  • Henry Liu
  • Annie Dupuis
  • Carol A. WestallEmail author
Original Research Article



The anti-epileptic drug vigabatrin is associated with reduction in light-adapted 30-Hz flicker electroretinogram (ERG) amplitude. Ophthalmological assessments, including ERGs, monitor retinal health during vigabatrin treatment. RETeval™ is a hand-held ERG device adapted for dilation-free ERG assessment. To evaluate the usefulness of RETeval™ for vigabatrin ERG assessment, we evaluated intra-visit reliability and clinical feasibility of RETeval™ ERG assessment in children under 3 years of age undergoing vigabatrin treatment.


In this prospective study, children underwent 30-Hz flicker ERG assessment with RETeval™ before routine vigabatrin monitoring including sedated-ERG using the Espion E2 Colour Dome. Intraclass correlation coefficient (ICC) statistics identified the degree of intra-visit reliability from two repeated measurements of the same participant within one testing session. The omega squared (ω2) statistic identified the level of association between RETeval™ and Espion light-adapted 30-Hz flicker responses.


Nine children completed RETeval™ ERG testing. The intra-visit ICCs for the RETeval™ 30-Hz flicker amplitude (µV) were high: 0.81 (right eye) and 0.86 (left eye), while the implicit times (ms) were 0.79 (right eye) and 0.42 (left eye). The RETeval™ 30-Hz flicker amplitude was positively associated with the Espion 30-Hz flicker response (ω2 = 0.71). The Bland–Altman plot showed no bias in the mean difference of amplitudes between the two systems.


This is the first study to assess the utility of RETeval™ device in children under 3 years of age undergoing vigabatrin treatment. RETeval™ demonstrated high intra-visit reliability with responses consistent with the standard Espion ERG. RETeval™ may be beneficial for assessment of retinal toxicity in young children treated with vigabatrin.


Electroretinography RETeval Hand-held electroretinography Vigabatrin Infantile spasms 



This work was supported by the Vision Science Research program at the University of Toronto (Xiang Ji), and the SickKids Ophthalmology Research Fund (Dr. Carol Westall). LKC Technologies, Inc. provided the RETeval™ device and some sensor strips electrodes used in this study.

Compliance with ethical standards

Conflicts of interest

The authors declare that they have no conflicts of interest.

Statement of human rights

All research procedures performed in this study 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.

Statement on the welfare of animals

This article does not contain any studies with animals performed by any of the authors.

Informed consent

Informed consent was obtained from all participants included in the study.


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Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2019

Authors and Affiliations

  • Xiang Ji
    • 1
    • 2
    • 3
  • Michelle McFarlane
    • 1
  • Henry Liu
    • 1
    • 4
  • Annie Dupuis
    • 5
  • Carol A. Westall
    • 1
    • 2
    • 3
    Email author
  1. 1.Ophthalmology and Vision SciencesThe Hospital for Sick ChildrenTorontoCanada
  2. 2.Institute of Medical ScienceUniversity of TorontoTorontoCanada
  3. 3.Ophthalmology and Vision SciencesUniversity of TorontoTorontoCanada
  4. 4.Faculty of MedicineUniversity of OttawaOttawaCanada
  5. 5.Clinical Research ServicesThe Hospital for Sick ChildrenTorontoCanada

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