Visual evoked potentials and visual prognosis following perinatal asphyxia
D. L. McCulloch, M. J. Taylor and H. E. Whyte
Department of Ophthalmology, Hospital for Sick Children, Toronto, Canada.
Twenty-five children born at term with perinatal asphyxia were studied at
age 2.5 to 4.5 years to evaluate visual function and to determine the
prognostic value of postnatal assessments of visual outcome. Postnatal
assessments included several visual evoked potentials and
electroretinograms in the first week of life. Follow-up assessments
included flash and pattern visual evoked potentials, visual evoked
potential threshold measurements, and clinical eye examinations. Nineteen
children had normal visual function, three were visually impaired, and
three remained blind. A strong association was found between normal,
abnormal, or absent visual evoked potentials in the early postnatal period
and long-term visual outcome (P less than .0001). Other perinatal
indicators of asphyxia, including neurologic status, Apgar scores, and
arterial pH values, were poor predictors of visual outcome. The risk of
visual impairment was limited to those survivors with neurodevelopmental
deficits.