Prevalence of Strabismus and Amblyopia in Preschool Aged Children: The Baltimore Pediatric Eye Disease Study

Abstract

Purpose: : To determine the age- and ethnicity-specific prevalence of strabismus and amblyopia in White and African-American preschool aged children.

Methods: : The Baltimore Pediatric Eye Disease Study is a population-based cross sectional evaluation of the prevalence of ocular disorders in children aged 6 through 71 months in Baltimore, Maryland, United States. Among 4,132 children identified, 3,990 eligible children (97%) were enrolled and 2,546 children (62%) were examined. While strabismus was evaluated in the entire study cohort, due to limited cooperation with optotype vision testing by younger children, amblyopia could be assessed in 1,714 of 2,546 examined children (67%) who were aged 30 through 71 months. Parents or guardians of eligible participants underwent an in-home interview and were scheduled for a comprehensive eye examination. A detailed eye examination including optotype visual acuity and measurement of ocular deviations using cover testing were conducted by study-certified pediatric optometrists. Amblyopia was defined as two or more lines of interocular acuity difference or vision worse than an age-specific criterion, in the presence of an amblyopiogenic factor.

Results: : Strabismus was identified in 34 of 1030 (3.3%) of White and 26 of 1268 (2.1%) of African American children. Esotropia and exotropia were equally prevalent for both groups. Strabismus prevalence increased with age. Only one case of strabismus was found among 84 children in the six through eleven months age range. Rates were higher in the oldest children (5.8% for Whites and 2.9% for African Americans 60 through 71 months of age). Amblyopia was present in 13 (1.9%) White and 7 (0.8%) African American children, and only one child had bilateral amblyopia. There was no consistent pattern of amblyopia prevalence with age.

Conclusions: : Strabismus affected 3.3% of White and 2.1% of African American preschool aged children, with an equal prevalence of esotropia and exotropia. Amblyopia was less common in this urban population, affecting 1.9% of White and 0.8% of African American children.

Keywords: esotropia and exotropia • amblyopia