The visual evoked potential(VEP) test is one of the important tools, useful for screening visual impairment and measuring brain maturity in the neonatal stage. The purpose of this study is to standardize the VEP latency and amplitude according to
the
gestational age, and to compare the factors which affect the VEP latency and amplitude. VEP to flash light stimulation by use of goggle have been obtained in fifty seven healthy neonates. The babies were born between thirty five to forty two
weeks
gestational age (mean 39 weeks) and VEP study was taken below three days after birth during their natural sleep.
@ES The results are as follows:
1) In the VEP study stimulating right eve, the mean latency of NI(initial negative peak) was 143.09 msec, PI(initial positive peak) was 209.67 msec and N2(negative peak) was 326.97 msec. The mean amplitude of I(N1-Pl) was 5.00μV and II(Pl-N2)
was
11.80μV.
2) In the VEP study stimulating left eye, the mean latencv of N1 was 145.40 msec, Pl was 211.44 msec and N2 was 331.12 msec. The mean amplitude of I was 5.28μV and II was 10.84μV.
3) In the VEP study stimulating both eyes simultaneously, the mean latency of N1 was 141.00 msec, Pl was 201.46 msec and N2 was 326.52 msec. The mean amplitude of I(N1-Pl) was 6.13μV and II(Pl-N2) was 15.05μV.
4) There are no significant correlations between right or left N1 latencies and gestational age(p>0.05), but bilateral N1 latency significantly decreased as gestational age increased (p<0.05).
5) The latencies of Pl and N2 of the right and left eye individually or simultaneously were inversely related to gestational age(p<0.05).
6) Statistically, the amplitudes of I(N1-Pl), II(Pl-N2) and the ratio of II/I of the right and left eye individually or simultaneously had no significant correlations with gestational age(p>0.05).
7) The Pl latency of VEP was significant differences in head circumference between the groups(p>0.05).
8) The VEP latencies or amplitudes were not significantly related to head circumference, body weight or APGAR score(p>0.05).
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