Prevalence of Astigmatism in 6-to 72-Month-Old African American and Hispanic Children: The Multi-Ethnic Pediatric Eye Disease Study

Purpose: To determine the age-, gender-, and ethnicity-specific prevalence of astigmatism in African American and Hispanic children aged 6 to 72 months. Design: Population-based, cross-sectional study. Participants: The Multi-Ethnic Pediatric Eye Disease Study is a population-based evaluation of the prevalence of vision disorders in children ages 6 to 72 months in Los Angeles County, California. Seventy-seven percent of eligible children completed a comprehensive eye examination. This report provides the results from 2994 African American and 3030 Hispanic children. Methods: Eligible children in 44 census tracts were identified during an in-home interview and scheduled for a comprehensive eye examination and in-clinic interview. Cycloplegic autorefraction was used to determine refractive error. Main Outcome Measures: The proportion of children with astigmatism defined as cylindrical refractive error >= 1.50 diopters (D) in the worse eye. The astigmatism type was defined as with-the-rule (WTR) (+ cylinder axis 90 +/- 15 degrees) and against-the-rule (ATR) (+ cylinder axis 180 +/- 15 degrees); all other orientations were considered oblique (OBL). The prevalence of astigmatism and its types were also determined for worse eye cylindrical refractive error >= 3.00 D. Results: Prevalence of astigmatism >1.50 D was higher in Hispanic children compared with African American children (16.8% vs. 12.7%, respectively; P < 0.0001). Hispanic children also showed a higher prevalence of astigmatism >= 3.00 D than African American children (2.9% vs. 1.0% respectively; P < 0.0001). The prevalence of astigmatism >1.50 D showed a significant decreasing trend with age (P < 0.0001). The prevalence of WTR, ATR, and OBL astigmatism >= 1.50 D was 13.9%, 0.6%, and 2.2%, respectively, in Hispanic children, and 7.8%, 2.2%, and 2.7%, respectively, in African American children. Conclusions: We observed ethnicity-related differences in astigmatism prevalence in preschool children. The age-related decrease in astigmatism prevalence in preschool children likely reflects emmetropization.