Related Experiment Videos
Visual function in full-term infants with hypoxic-ischaemic encephalopathy
E Mercuri1, J Atkinson, O Braddick
1Visual Development Unit, University College London, UK.
Insights
Hypoxic-ischaemic encephalopathy (HIE) in infants can impact vision. Magnetic Resonance Imaging (MRI) findings, particularly lesion location and extent, are better predictors of visual outcomes than HIE severity alone.
Area of Science:
- Neuroscience
- Ophthalmology
- Pediatrics
Background:
- Hypoxic-ischaemic encephalopathy (HIE) is a major cause of brain injury in term infants.
- Visual impairment is a common complication of HIE, but prediction remains challenging.
Purpose of the Study:
- To determine if HIE severity or MRI lesion characteristics predict visual function in infants.
- To identify specific MRI findings associated with visual impairment.
Main Methods:
- Serial MRI and a battery of visual function tests were performed on 31 term infants with HIE (age 5-31 months).
- Infants were graded for HIE severity (I-III).
Main Results:
- Twenty of 31 infants had abnormal visual test results.
- MRI findings were more predictive of visual impairment than HIE grade.
- Normal MRI scans correlated with normal visual function.
- Diffuse hemispheric involvement and basal ganglia lesions were associated with severe visual impairment.
Conclusions:
- MRI lesion characteristics are superior to HIE severity in predicting visual outcomes.
- Infants with generalized lesions are at high risk for severe visual impairment.
- Early and comprehensive visual function assessment is crucial for infants with HIE, especially those with generalized brain lesions.
Abstract:
Thirty-one full term infants with hypoxic-ischaemic encephalopathy (HIE) were studied with a battery of tests designed to evaluate visual function in infancy and with serial MRI. Their age ranged between 5 and 31 months. The aim of the study was to evaluate whether the degree of HIE or the site and size of lesions on MRI could predict visual outcome. Twenty of the 31 infants studied showed abnormal results on at least one of the visual tests used. While visual function was generally normal in grade I HIE and severely impaired in grade III, visual outcome was variable in grade II. MRI findings were better predictors of visual impairment than the degree of HIE. Normal scans tended to be associated with normal visual function, irrespective of the severity of HIE. All but one of the infants with diffuse hemispheric involvement also showed multiple visual abnormalities. The concomitant involvement of basal ganglia was always associated with more severe visual outcome. These results suggest that infants with generalised lesions secondary to global insults are at high risk of severe visual impairment even in presence of normal acuity and require early assessment of various aspects of visual function.