A comparison of tests to determine acuity deficits in children with amblyopia.

The usefulness of the Cardiff Acuity Test in the detection of amblyopia was evaluated. Visual function was measured using pattern visual evoked potentials (VEPs), the Cardiff test, and the Bailey-Lovie Chart in 21 visually normal children and 12 children with amblyopia. The Cardiff test gave higher scores than the Bailey-Lovie test. The Cardiff test identified five of the 12 children who were classified as amblyopic by the Bailey-Lovie test. Interocular VEP latency differences identified eight of the 12 children with amblyopia; interocular VEP amplitudes correctly identified nine. We suggest that the challenging Bailey-Lovie test be used for older children who know their letters well. If the Bailey-Lovie test cannot be used, VEPs give the most accurate assessment of interocular differences. The Cardiff test holds a bored child's attention and allows the examiner to obtain a useful measure of visual acuity, but it cannot detect mild amounts of amblyopia.