Purpose: 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.
Methods: 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.
Results: 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.
Conclusion: 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.
Keywords: Electroretinography; Hand-held electroretinography; Infantile spasms; RETeval; Vigabatrin.