Which ocular and neurologic conditions cause disparate results in visual acuity scores recorded with visually evoked potential and teller acuity cards?

Purpose:We investigated whether disparity between visually evoked potential (VEP) acuity scores and Teller Acuity Card (TAC) scores varied according t o presence of ocular or neurologic conditions. Methods: Charts from 175 chi ldren (mean age, 34.8 months; range, 3 to 158 months) referred for Visual a cuity testing were examined. All children had been tested with pattern-alte rnation VEP and TAC and had undergone a complete eye examination. VEP and T AC acuity scores were relative to age-expected acuity scores for each acuit y test. The absence and degree of macular abnormality, retinal abnormality, optic nerve hypoplasia, optic nerve atrophy, cortical visual impairment, d evelopmental delay, cerebral palsy, seizures, and nystagmus were noted. Ana lysis of variance models were used to determine whether differences between VEP and TAC scores varied according to the presence of specific deficits. Logistic regression analysis determined whether degree of specific deficits was associated with a greater chance of inconsistency between VEP and TAC scores (>0.3 log unit difference). Results: Inconsistent scores were found in 48% of children. Developmental delay was associated with relatively poor er TAC than VEP score, and the chance of inconsistency increased with sever ity of developmental delay. Conclusions: Diagnosis-dependent variability ex ists between TAC and VEP scores. Therefore knowledge of the clinical pictur e is necessary in interpretation of VEP and TAC scores. It is not clear whi ch test is more useful when a disparity exists, either from this or previou s studies. When visual acuity is assessed longitudinally in a given child, then consistency in method for acuity assessment is important.