Abstract
Purpose. Pre-term infants are at risk of abnormal visual development that can range from subtle to severe. The aim of this study was to compare flash VEPs in clinically stable pre-term and full-term infants at 6 months of age. Methods. Twenty-five pre-term and 25 full-term infants underwent flash VEP testing at the age of 6 months. Monocular VEPs were recorded using flash goggles on a RETIscan system under normal sleeping conditions. Amplitude and peak time responses of the P2 component in the two eyes were averaged and compared between the two groups. Multiple regression analyses were performed to assess the relationship of the P2 responses with birth weight (BW) and gestational age (GA). Results. At 6 months corrected age, pre-term infants had significantly delayed P2 peak times than full-term infants (mean difference, 10.88 [95% CI 4.00-17.76] ms, p = 0.005). Pre-term infants also showed significantly reduced P2 amplitudes as compared to full-term infants (mean difference, 2.36 [0.83-3.89] µV, p = 0.003). Although the regression model with GA and BW as fixed factors explained 20% of the variance in the P2 peak time (F2,47 = 5.98, p = .0045), only GA showed a significant negative relationship (β = -2.66, p = .003). Neither GA (β = 0.21, p = .28) nor BW (β = 0.001, p = .32) showed any relationship with P2 amplitude. Conclusions. Our results demonstrate that, compared with full-term infants, clinically stable pre-term infants exhibit abnormal flash VEPs, with a delay in P2 peak time and a reduction in P2 amplitude. These findings support a potential dysfunction of the visual pathway in clinically stable pre-term infants as compared to full-term infants.