Abstract
Purpose To investigate the effect of vigabatrin on contrast sensitivity and visual acuity in infants with Infantile Spasms (IS).
Methods Sweep visual evoked potentials were used to assess contrast sensitivity and visual acuity in infants (8mos – 2.1 yrs, median 9.5 mos) with IS pre-vigabatrin (baseline). These results were compared with historical sweep VEP data of children (1.3yrs – 1.5yrs, median 1.45 yrs) with normal vision. Baseline results were also compared with historical data of age-similar children on vigabatrin: (1) showing NO signs of toxicity and (2) showing signs of toxicity (as determined by fundus examination and ERG).
Preliminary Results A two-tailed t-test showed that infants (n=9) with IS had a significant peak contrast sensitivity deficit (p<0.02) and a significant visual acuity deficit (p<0.01) before starting vigabatrin compared with infants with normal vision. A slight reduction in peak contrast sensitivity is seen in children showing signs of toxicity, when compared to baseline results.
Discussion Infants with IS have significant visual deficits in contrast sensitivity and visual acuity. Longitudinal follow up will determine the effect of vigabatrin on visual functions
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