ABSTRACT
PURPOSE: To determine the clinical usefulness of the Teller Acuity Cards(TAC) test in infants and preverbal children less than 48 months old. METHODS: We retrospectively analyzed 55 consecutive patients. We had measured visual acuity with the TAC test for the preverbal period, and optotype acuity was measured with Hahn's letter chart for the follow-up period. Test-retest long-term repeatability was evaluated by comparing the last two TAC acuities. We compared the last TAC acuity with the first optotype acuity to estimate the predictive validity of the TAC test. Finally, we also tested the reliability of the TAC test compared with the optotype acuity test for the assessment of interocular visual acuity differences in patients with unilateral amblyopia. RESULTS: The mean age of patients at the initial TAC test was 21.6 months. The first optotype acuity was obtained at the age of 37 months. Earlier TAC acuity correlated significantly with later TAC acuity (r=0.77, p<0.001). Although the TAC test underestimated the visual acuity more than the optotype test, there was minimal correlation between the two tests (r=0.28, p<0.05). In the presence of the interocular difference of visual acuity with the TAC test, unilateral amblyopia as assessed by optotype test could be anticipated (r=0.44, p<0.05). CONCLUSIONS: The TAC test can be used as a reliable method to estimate visual acuity in infants and preverbal children. Earlier The TAC acuities are valid predictors of optotype acuities later in childhood. The TAC test is an especially useful method in detecting unilateral amblyopia.