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Flash VEP in clinically stable pre-term and full-term infants
Anish Kharal1, Safal Khanal2, Jyoti Baba Shrestha1
1B.P. Koirala Lions Centre for Ophthalmic Studies, Institute of Medicine, Tribhuvan University, Kathmandu, Nepal.
Insights
Pre-term infants show delayed visual development, with abnormal flash visual evoked potentials (VEPs) including slower P2 peak times and reduced P2 amplitudes compared to full-term infants.
Area of Science:
- Ophthalmology
- Neuroscience
- Developmental Pediatrics
Background:
- Preterm infants face risks for abnormal visual development.
- Visual pathway function can be subtly or severely affected.
- Early identification of visual pathway dysfunction is crucial.
Purpose of the Study:
- To compare flash visual evoked potentials (VEPs) in clinically stable preterm and full-term infants.
- To assess visual pathway maturation at 6 months corrected age.
- To investigate the relationship between VEPs and perinatal factors like gestational age and birth weight.
Main Methods:
- Flash VEPs were recorded in 25 preterm and 25 full-term infants at 6 months corrected age.
- Monocular VEPs were analyzed for P2 component amplitude and peak time.
- Regression analyses explored associations with gestational age (GA) and birth weight (BW).
Main Results:
- Preterm infants exhibited significantly delayed P2 peak times (10.88 ms difference, p=0.005).
- Preterm infants showed significantly reduced P2 amplitudes (2.36 µV difference, p=0.003).
- Gestational age was negatively related to P2 peak time (p=0.003), but neither GA nor BW related to P2 amplitude.
Conclusions:
- Clinically stable preterm infants demonstrate abnormal flash VEPs at 6 months corrected age.
- Delayed P2 peak time and reduced P2 amplitude suggest visual pathway dysfunction.
- These findings highlight the importance of monitoring visual development in preterm populations.
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.
