Visual Acuity Charts Comparison for Preschool Vision Screening

ABSTRACT

We assessed the best method for preschool vision screening using four visual acuity charts. The subjects were 162 childrens(324 eyes), who were divided into all aged group(162 childrens), 3-year-old group(58 childrens), 4-year-old group(58 childrens) and 5-year-old group(46 childrens), We compared Hahn's test, HOTV test, Allen figures and E test by measuring the time required for test, the percentage of children testable with each chart, visual acuity score and consistency of score. There was no significant differences among the time of each group(p>0.05). Visual acuity score with Hahn's test was lower than that of the rest 3 tests in all aged group and 3-year-old group(p<0.05). The percentage of children testable with Hahn's test was lower than that with the other tests(p<0.05). For assessing the consistency, analysis of variance was used. E test was more variable than the other test and Allen figures showed most consistency than the other tests(p<0.05). In young chidren, there were some difficulties in measuring visual acuity with Hahn's test, and the E test caused variable results because of difficulty in distinguishing the left-right orientation, but relatively Allen figures showed consistency, high visual acuity and testability in all groups.