Association Between Electroretinogram-identified Vigabatrin Toxicity and Subsequent Visual Field Reduction

• Main Author: Kumarappah, Ananthavalli
• Other Authors: Westall, Carol
• Language: en_ca
• Published: 2014
• Subjects: vigabatrin; visual fields; 0317
• Online Access: http://hdl.handle.net/1807/65553

Vigabatrin (VGB) is an antiepileptic drug approved for pediatric patients with infantile spasms. VGB is associated with visual field reductions in 30-50% of adults taking the drug. The amplitude of the 30-Hz flicker electroretinogram (ERG) is recommended for screening young children on VGB treatment. To determine if standard ERG tests for VGB toxicity are correlated with visual field reductions, 22 individuals who were previously on VGB underwent visual assessment. This study also validated the use of high-resolution OCT for detecting structural changes associated with VGB toxicity. This study demonstrates that the ERG was associated with visual field loss, as measured along the temporal meridian. The retinal nerve fibre layer (RNFL) was attenuated in all children who showed a reduction in the visual fields indicating that RNFL attenuation may be a sensitive marker for VGB toxicity. We recommend using serial OCTs to monitor VGB toxicity since it is fast and non-invasive.