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.