Abstract
Purpose::
To determine the prevalence of amblyopia and strabismus in a population-based sample of African-American (AA) and Hispanic (Hisp) children aged 6-72 months.
Methods::
Participants aged 6-72 months were recruited from 37 census tracts in Inglewood, Los Angeles County, Calif., as part of the Multi-Ethnic Pediatric Eye Disease Study (MEPEDS). All eligible children underwent comprehensive age-specific clinical examinations. Visual acuity was measured using the Amblyopia Treatment Study (ATS) protocol (single surround HOTV optotypes) for those children who could perform the task. Fixation preference testing was also performed on all participants and was used as the surrogate visual acuity test for infants and toddlers. Amblyopia was determined using a predefined definition of a reduction in best-corrected visual acuity in the presence of a pre-determined amblyogenic factor. Strabismus was determined on the basis of cover uncover testing at distance and near with Hirschberg testing performed in those rare instances when cover testing was unsuccessful. Age-, gender-, and ethnicity-specific prevalences were calculated and compared using chi-square and analysis of variance testing.
Results::
5032 of the 6593 eligible children were examined (76% participation rate). 2303 children were AA and 2609 were Hisp. The overall prevalence of amblyopia was 1.4% (68/5032) with similar prevalences in AA and Hisp children (AA: 1.2% - 26/2303; Hisp: 1.6% - 40/2609, p=0.22). Overall, the types of amblyopia were anisometropic (55%), isoametropic (19%), strabismic (12%), combined strabismic/anisometropic (7%), deprivation (1%) and other (6%). Older children were more likely to have amblyopia compared to younger children (odds ratio per month older age 1.04, p<0.0001). The overall prevalence of strabismus was 2.5% (125/5032) with similar prevalences in AA and Hisp children (AA: 2.6% - 59/2303; Hisp: 2.5% - 63/2609, p=0.74). Overall, 61% had exotropia and 38% had esotropia. Children aged 49 months and older were more likely to have strabismus compared to younger children (odds ratio 2.18-2.29, p<0.04). No gender-related differences in the prevalence of amblyopia or strabismus were present.
Conclusions::
These data provide the first population-based prevalence estimates of amblyopia and strabismus in minority preschool children in the U.S.
Keywords: clinical (human) or epidemiologic studies: prevalence/incidence • amblyopia • strabismus