Anisometropia in Hispanic and african american infants and young children the multi-ethnic pediatric eye disease study.

PURPOSE: To determine anisometropia prevalence and associated risk factors in Hispanic and African American preschoolers.
DESIGN: Population-based, cross-sectional study. PARTICIPANTS: We included 3030 Hispanic and 2994 African American children aged 6 to 72 months from Inglewood, California.
METHODS: Retinomax autorefraction was performed on all participants after cycloplegia. Anisometropia was defined by difference in spherical equivalent (SE), by difference in plus cylinder in any axis (cylindrical), and by difference in cylinder axis vectors (vertical Jackson cross cylinder vector [J0] and oblique Jackson cross cylinder vector [J45] between the eyes. Strabismus was determined by prism-cover testing. A parental questionnaire explored potential risk factors including developmental delay, prematurity, prenatal exposure, and family history. MAIN OUTCOME MEASURES: Anisometropia prevalence stratified by age, gender, and ethnicity. The association of anisometropia with strabismus and other biological risk factors was assessed.
RESULTS: The prevalence of SE anisometropia > or =1.0 diopter (D) was 4.3% for Hispanics and 4.2% for African Americans. Prevalence of cylindrical anisometropia > or =1.0 D was 5.6% and 4.5%, respectively. Prevalence of cylindrical or SE anisometropia > or =3.0 D was < or =0.4% for both ethnic groups. Cylinder vector anisometropia > or =0.5 was twice as common as cylindrical anisometropia > or =1.0 D. The SE anisometropia decreased at age 1 year in Hispanics (P = 0.0016) but not African Americans. Cylindrical anisometropia decreased in the first year of life in both ethnic groups (P < or = 0.001). There was no trend in SE or cylindrical anisometropia beyond 1 year of age, but cylinder vector anisometropia steadily decreased beyond 1 year of age in both ethnic groups. Cylinder vector anisometropia was more prevalent among African Americans, but there was no difference in other measurements of anisometropia between ethnic groups. Anisometropia did not vary by gender. Strabismus was associated with all types of anisometropia. No association of anisometropia with gestational age, birth weight, cerebral palsy, family history, or prenatal exposure could be identified.
CONCLUSIONS: Spherical and cylindrical anisometropia (> or =1.0 D) each affect 4% to 6% of Hispanic and African American preschoolers. Anisometropia > or =3.0 D is rare. Except for cylinder axis vector, the prevalence of anisometropia does not diminish beyond 1 year of age. Strabismus is associated with all forms of anisometropia. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any of the materials discussed in this article. Copyright 2010 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.