Abstract
Purpose: :
To determine the prevalence of myopia by age, gender, and ethnicity in Hispanic and African-American children 6 to 72 months of age.
Methods: :
A population-based cohort of children 6-72 months of age underwent Retinomax autorefraction 30 to 60 minutes after cycloplegia with 2 drops of 1% cyclopentolate 5 minutes apart (0.5% for children <=12 months of age). If drops were refused, noncycloplegic retinoscopy was performed, and if Retinomax readings had a confidence interval <8, cycloplegic retinoscopy was performed. The eye with the greater absolute value spherical equivalent (SE) refractive error was analyzed. Myopia is defined as 1 D SE or greater.
Results: :
Refractive error was measured in 3024 Hispanic and 2993 African-American children. Myopia prevalence decreased with age, being 10% (n=572), 8.2% (n=1091), 5.2% (n=1114), 3.5% (n=1061), 3.0% (n=1092), and 3.2% (n=1087) in children aged 6-11, 12-23, 24-35, 36-47, 48-59, and 60-72 months, respectively. The decrease was significant in both African-American and Hispanic children (p<0.0001 for both groups; trend test). There was no significant difference in myopia prevalence between genders in either ethnic group (Hispanic, p=0.15; African-American, p=0.59; logistic regression adjusting for age). Myopia was more prevalent in African-American children (6.6%) than Hispanic children (3.7%) (p<0.0001, logistic regression adjusting for age). Overall, for every age group, there is a higher prevalence of myopia in African-American children.
Conclusions: :
Myopia prevalence is higher in African-American preschool children than in Hispanic preschool children. In contrast to studies examining school-aged children, these preschool children do not show increasing myopia with increasing age; on the contrary, myopia is more frequent in children younger than three years of age than in older preschool children, presumably reflecting active emmetropization in the first few years of life.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence