Electrophysiological evaluation of retinal function in children receiving vigabatrin medication.
OBJECTIVE
To evaluate retinal function in children taking vigabatrin and to explore the influence of age and dose parameters on the results of full-field electroretinography (ff-ERG).


METHODS
The ff-ERGs from 14 children receiving vigabatrin were compared with ff-ERGs from healthy controls. Treated children were further grouped according to age (pre-school = 12-71 months; older = 72-228 months). Parameters of drug dosage were compared.


RESULTS
Treated children showed rod and cone dysfunction reflected by reduced b-wave amplitudes for the isolated rod response, the combined rod-cone response, and the 30-Hz flicker response. The a-wave amplitude and implicit time for the combined rod-cone response, reflecting photoreceptor function, were also altered. Further evaluation of age groups revealed similar findings in the pre-school group but not in the older group. Alterations in ff-ERG were seen in 57% of the treated children. Pre-school children had received significantly higher daily drug doses with start of medication at younger age. No differences were found concerning cumulative doses or duration of medication.


CONCLUSIONS
Alterations in ff-ERG are as frequent in children as in adults and the results indicate that exposure to high daily doses of vigabatrin may be associated with increased risk of retinal dysfunction, including photoreceptor damage, not previously shown in children. Thus, recommendations of careful follow-up for children receiving vigabatrin are supported.
Department of Ophthalmology, University of Lund, Lund, Sweden. ulrika.kjellstrom@med.lu.se
Ulrika
U
Kjellström
Sten
S
Andréasson
Vesna
V
Ponjavic
D000293:Adolescent; D000927:Anticonvulsants / Q000008:administration & dosage / Q000009:adverse effects*; D002648:Child; D002675:Child, Preschool; D055724:Electrophysiological Phenomena; D004596:Electroretinography / Q000187:drug effects*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010775:Photic Stimulation; D020419:Photoreceptor Cells, Vertebrate / Q000187:drug effects* / Q000502:physiology; D012160:Retina / Q000503:physiopathology*; D012164:Retinal Diseases / Q000139:chemically induced* / Q000503:physiopathology; D012640:Seizures / Q000188:drug therapy; D013036:Spasms, Infantile; D020888:Vigabatrin / Q000008:administration & dosage / Q000009:adverse effects*
D000927:Anticonvulsants; D020888:Vigabatrin