Preferential looking acuity obtained with a staircase procedure in pediatric patients.

Visual acuity of infants and young children with ophthalmologic disorders was assessed by adapting a transformed up-down staircase to preferential looking (PL) procedures. Eighty-five percent of pediatric patients between 11 days and 5 years of age were tested successfully. Acuity of infants and young children with normal eyes obtained by the PL staircase procedure agreed well with acuities obtained previously by the method of constant stimuli. In children with anisometropia, differences in acuity between eyes varied systematically with the amount of anisometropia. Monocular acuities of untreated patients with strabismus did not always agree with fixation preference. In general, test results from pediatric patients with structural ocular abnormalities were consistent with the severity of the disorder. By means of serial measurement of PL acuity, the therapy of patients with amblyopia was monitored. In our young patients, anisometropic amblyopia affected grating acuity differently than did strabismic amblyopia, as others have reported in older patients with these conditions. Our results indicate that the PL staircase procedure provides a useful measure of visual acuity in pediatric ocular disorders that can complement the clinical evaluation of infants and young children.