Visual Acuity Norms in Pre-School Children: The Multi-Ethnic Pediatric Eye Disease Study

Purpose. To provide population-based normative data for monocular visual acuity (VA) and interocular differences in VA (IOD) in Black and Hispanic children 30 to 72 months of age without visually significant refractive errors or ophthalmic abnormalities. Methods. In a population-based cohort of children in the Multi-Ethnic Pediatric Eye Disease Study, monocular HOTV VA measurements using the Amblyopia Treatment Study protocol were analyzed using continuous and dichotomous outcomes for VA and IOD, after excluding subjects with ophthalmic abnormalities or refractive error. Results. The analysis cohort consisted of 1722 Black and Hispanic children aged 30 to 72 months. Mean logMAR VA improved with age (p < 0.0001) and male gender (p = 0.0008). The proportion of children achieving VA 20/40 or better was associated with age (p < 0.0001), hid not ethnicity or gender, end was 81, 94, 99, and virtually 1000, in children aged 30 to 35, 36 to 47, 48 to 59, and 60 to 72 months of age, respectively. The most stringent VA threshold that excluded <5%, of normal children was 20/63, 20/50, 20/32, and 20/32 for children aged 30 to 35, 36 to 47, 48 to 59, end 60 to 72 months, respectively. Children attending preschool or daycare achieved VA 20/32 more often than those not attending, after age adjustment (p = 0.01), as did children from higher-income families (p = 0.04). There. vas no association between mean absolute IOD end age (p = 0.45), ethnicity (p = 0.12), or gender (p = 0.19). The proportion of children with en IOD of 0 to 1 lines was higher in males than females (p = 0.02); it did not vary by age (p = 0.06) or ethnicity (p = 0.17). An IOD of 2 or more lines occurred in 6% of normal children. Conclusions. VA test performance in normal pre-school children improves with age. We propose new age-specific thresholds for defining abnormal monocular VA using HOTV optotypes in children between 2 and 5 years of age, for use in screening, clinical practice, end research. (Optom Vis Sci 2009;86:607-612)