Visually evoked potential (VEP) acuity: testability in a clinical pediatric population.

The visually evoked potential (VEP) elicited by pattern response is used to assess the visual acuity of preverbal infants in research situations, but few reports indicate the percentage of patients successfully completing the tests (testability). Data are presented to illustrate the testability of acuity assessed by VEPs with clinical populations of preverbal and neurologically handicapped children. 166 referrals in a 9-month period to an electrodiagnostic clinic indicated that 75% of the referrals less than 3 years old, and 87% of the neurologically handicapped referrals were testable. The testability of VEP acuity is as great or greater than other procedures for examining the visual functions of non-verbal or unco-operative patients.