Walsh & Hoyt: Ocular Motor Manifestations of Some Metabolic Disorders

Some babies who ultimately develop normally show transient ocular motor disturbances, including upward or downward deviation of the eyes (but with a full range of reflex vertical movement), intermittent opsoclonus, and skew deviation. The last may be associated with the eventual development of horizontal strabismus. In addition, premature babies may show reduced excursion of the adducting eye with caloric stimulation, suggesting an INO. In such infants, full deviation of both eyes usually occurs with rotational stimuli, although quick phases of nystagmus may be absent. The time constant of the VOR (as reflected in the duration of nystagmus to a sustained constant velocity stimulus) in newborns is low (typically 6 seconds) and does not attain adult values until the infant is about 2 months old. Thus, normal infants may have abnormal eye movements.