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Effect of bilirubin on visuocortical development in preterm infants
William V Good1,2, Ronald J Wong3, Anthony M Norcia4
1The Smith-Kettlewell Eye Research Institute, San Francisco, CA, USA. Good@ski.org.
Insights
High bilirubin levels significantly impact visuocortical development in premature infants, particularly those born before 34 weeks gestation. Vernier acuity is notably affected, suggesting a need to revise hyperbilirubinemia management guidelines for these vulnerable infants.
Area of Science:
- Neonatal neurology
- Developmental pediatrics
- Visual neuroscience
Background:
- High bilirubin levels (hyperbilirubinemia) pose a risk to infant neurodevelopment.
- The impact of hyperbilirubinemia on visuocortical development in premature infants requires further investigation.
Purpose of the Study:
- To compare the effects of high bilirubin levels on visuocortical development between premature and full-term infants.
- To identify specific visual functions most vulnerable to bilirubin toxicity in preterm neonates.
Main Methods:
- A cohort of 57 preterm infants was studied, adhering to institutional hyperbilirubinemia management protocols.
- Visual functions including Vernier acuity, contrast sensitivity, and grating acuity were assessed at 12 months corrected age using sweep visual evoked potentials (sVEP).
- These visual measures were correlated with total serum/plasma bilirubin (TSB) levels recorded in the first week of life.
Main Results:
- Increased TSB levels correlated with worsened Vernier acuity in infants born before 34 weeks gestation compared to those born between 34-37 weeks (p < 0.001).
- Contrast sensitivity showed a significant variation related to TSB levels (Spearman correlation 0.63, p < 0.001).
- Grating acuity did not appear to be affected by TSB levels.
Conclusions:
- Vernier acuity in preterm infants (<34 weeks gestation) is particularly susceptible to bilirubin's adverse effects.
- These findings suggest that the extrastriate visual cortex is a primary target of bilirubin toxicity in this population.
- Current guidelines for managing hyperbilirubinemia in preterm infants (<34 weeks gestation) may need revision to better protect visual development.
Objective:
To determine if visuocortical development in premature infants with high bilirubin levels is more adversely affected than that in full-term infants.
Study Design:
57 preterm infants were managed using institutional guidelines for hyperbilirubinemia. At 12-months corrected age, Vernier acuity, contrast sensitivity, and grating acuity measured using the sweep visual evoked potential (sVEP) were correlated to total serum/plasma bilirubin (TSB) levels in the first week of life.
Result:
As TSB levels increased, Vernier acuity worsened in infants <34 weeks' gestation compared with those >34 to <37 weeks' gestation (p < 0.001). Contrast sensitivity varied as a function of TSB levels (Spearman correlation 0.63, p < 0.001). Grating acuity was unaffected.
Conclusion:
Vernier acuity in preterm infants <34 weeks' gestation is more vulnerable to the effects of bilirubin, suggesting that the extrastriate visual cortex is primarily affected by bilirubin. Therefore, guidelines for management of hyperbilirubinemia in preterm infants (<34 weeks' gestation) should be revised.
