VISUAL-ACUITY ASSESSMENT OF CHILDREN WITH NEUROLOGICAL IMPAIRMENT USING GRATING AND VANISHING OPTOTYPE ACUITY CARDS

We have compared the testability and acuity thresholds achieved with v anishing optotype acuity cards and traditional grating acuity cards wh en used to examine children with neurological impairment. These childr en encompass a wide range of ages and abilities and it may be desirabl e to use the two types of cards for acuity assessment. Subjects were a diverse group of children (n = 91; 8 months - 19 years) whose learnin g ability ranged from normal to severe disability There was no signifi cant difference between the individual success rates for the two sets of cards (grating 91% (n = 61) vanishing optotype 89% (n = 59)), Over a wide range of acuities (0 to 2.0 LogMAR) the mean difference between acuity thresholds did not differ significantly from zero (p = 0.24). Ninety-three percent of acuity estimates agreed to within +/- 0.50 Log MAR units. The results indicate that the two acuity tests could be use d interchangeably in clinical populations of children with neurologica l impairment.