Questionable ERG use for Vigabatrin screening
Reviewed by Fiona Rowe

The authors aimed to identify the usefulness of electroretinograms (ERGs) as screening for retinal toxicity in patients taking Vigabatrin in a single centre study. This was a retrospective review of full field ERGs and included 170 ERGs of 138 patients under GA. Mean age was 5.19 years (three months to 52 years). One hundred and forty-seven ERGs had results available for analysis. Of these, only three were normal: two of which were for screening. Of those screened specifically for Vigabatrin use, 33 ERGs were undertaken for 29 patients and 30 were available for analysis. Two were normal and 28 (24 patients) were abnormal. Of the 24 patients, 13 continued Vigabatrin use and 11 stopped but only one because of the ERG result. ERG responses included scotopic amplitudes depressed at 1 and 24dB. Scotopic and photopic implicit times were frequently elevated. Five patients had a decrease in 30Hz flicker 1-wave. Flicker implicit time was abnormal in all but one patient. The authors suggest their results argue that ERGs should not be used to guide the management of paediatric patients taking Vigabatrin. Their results demonstrate a degree of non-specific ERG findings. Further, normative ERG values in the young paediatric population remain to be defined, and ERG measures change with age as the retina matures in childhood. They conclude ERG under GA every three to six months in young children is inconvenient, costly and potentially dangerous and ERG screening in this population of Vigabatrin screening should be reconsidered.

Clinical utility of electroretinograms for evaluating Vigabatrin toxicity in children.
Strong AD, Sturdy A, McCourt EA, et al.
JOURNAL OF PEDIATRIC OPHTHALMOLOGY AND STRABISMUS
2021;58:174-9.