Abstracts

Vigabatrin has been shown to cause visual field constriction in 40% of treated adults. The risk is less well known in children. There are no previous reports on visual fields in children who received vigabatrin in infancy., Vigabatrin has been used as the first drug for infantile spasms in our unit since 1994. We have aimed to investigate visual fields in all VGB-treated children whose age and developmental level allow sufficient cooperation. Eleven such children born in 1993-1999 were available for study. All had infantile spasms during the first year of life, nine with idiopathic and two with symptomatic etiology. Spasms started at a median age of 5.2 (range, 2.9-11.9) months, and lasted for a median of 22 (range, 1-88) days. Ten children have remained seizure-free and one relapsed with focal seizures. Neuropsychological testing at age 5-6 years showed normal cognitive performance in eight children and mild cognitive dysfunction in three. Visual fields were tested by experienced nurses, using the kinetic Goldman perimeter with standard objects V/4e and I/3e in ten children, and IV and 4 in one. Normal result was defined as the fields extending [underline][gt][/underline]70 degrees in the temporal meridian., Vigabatrin was started at median age 5.5 (range 3.2-12.5) months and lasted for a median of 23.7 (12.6-29.8) months. The median cumulative dose was 733 (range, 284-995) g. Vigabatrin was the only treatment in six children while five also received ACTH. The results of the first Goldman perimetry performed at a median age of 7.2 (range, 6.0-10.6) years were normal in seven children. Three children showed mildly abnormal or uncertain findings in the first testing but had normal results at the second perimetry at 8.7-10.8 years. Temporal fields of one child who was tested only once at 6.6 years extended to 65 degrees., The risk of visual field constriction after vigabatrin treatment may not be as high in infancy as in adulthood.,