Abstract
Purpose::
To describe age-, gender- and ehtnicity-specific Amblyopia Treatment Study (ATS) HOTV test results using the Electronic Visual Acuity (VA) Tester in African-American and Hispanic children 30 to 72 months of age without visually significant clinical abnormalities or refractive error.
Methods::
A population-based cohort of children 30-72 mos. of age underwent ATS HOTV testing, right eye (RE) first. All children had a full clinical examination with refraction (cycloplegic in >97% of children). We report presenting RE VA in children without glasses (>99% of children), and without ≥3D RE spherical equivalent (SE) hyperopia, ≥0.5D RE SE myopia, ≥1D RE astigmatism, ≥1D SE anisohyperopia, ≥3D SE anisomyopia, ≥1.5D anisoastigmatism, strabismus, visual axis occlusion, nystagmus, or anterior segment or fundus abnormalities affecting vision. Proportions of children with VA 20/40 or better, and mean logMAR VA for different age groups, genders and ethnicities were evaluated using chi-square analysis and the t-test.
Results::
1210 Hispanic and 1087 African-American children had HOTV testing (86% successful). VA was 20/40 or better in 77%, 93%, >99% and >99% of testable children 30-36 mos., 37-48 mos., 49-60 mos., and 61-72 mos. of age, respectively. There was significant improvement in test results with age (p<0.0001, trend test). There were no gender- or ethnicity-related differences in the proportion of children with VA 20/40 or better at any age, or overall after adjusting for age (p=0.86 for gender; p=0.55 for ethnicity). Mean (s.d.) logMAR VA values were 0.25 (0.15), 0.17 (0.14), 0.08 (0.10) and 0.02 (0.09) for children 30-36 mos., 37-48 mos., 49-60 mos. and 61-72 mos. of age, respectively. Mean VA did not differ between ethnicities in any age group (p≥0.12). Mean VA was better in males (0.07) than females (0.09) at 49-60 mos. of age (p=0.004), but not at other ages (p≥0.35).
Conclusions::
Preschool ATS HOTV test results are better in older children than younger children. This is likely to be related to cognitive maturation. By 4 years of age, virtually all children without clinical abnormalities or refractive error likely to affect vision, achieve 20/40 or better when first tested.
Keywords: visual acuity • clinical (human) or epidemiologic studies: systems/equipment/techniques • screening for ambylopia and strabismus