Abstract
Purpose: :
To evaluate biological, environmental and clinical risk factors associated with anisometropia in preschool children.
Methods: :
A population-based sample of African-American (AA) and Hispanic (Hisp) children aged 6-72 months underwent a comprehensive eye examination including cycloplegic Retinomax autorefraction. Spherical equivalent anisometropia (SE aniso) was defined by difference of 1D in hyperopia or myopia. Astigmatic anisometropia was a cylinder difference of 1D in any axis (cyl aniso), or a difference of 0.5 in Jackson cross axis vectors (J0/J45 aniso) between eyes. Medical and perinatal histories were determined from a detailed parental questionnaire. Potential biological (e.g. age, family history), environmental (e.g. prenatal exposures, daily activities) and clinical (e.g. maternal age, prematurity, strabismus, cerebral palsy [CP]) risk factors were assessed. Risk factors for SE aniso, cyl aniso and J0/J45 aniso were identified using univariate and multivariate logistic regression analyses. Odds ratios (OR) for independent risk factors are reported if confidence intervals excluded 1.0.
Results: :
3024 Hisp and 2993 AA children were tested. Only J0/J45 aniso was more prevalent in African-Americans than Hispanics (OR=1.2). SE aniso decreased with age in Hisp, but not in AA children. Beyond 12 months, only J0/J45 aniso prevalence decreased with age (p<0.0001, trend test). SE aniso and cyl aniso were associated with esotropia (OR=6.4; 3.1) or exotropia (OR=2.9; 3.5). Only J0/J45 aniso was associated with CP (OR=13.1). Only J0/J45 aniso was associated with decreased gestational age (OR=1.03/week).In children >=24 months of age, in whom anisometropia may be considered to be persistent, J0/J45 aniso was associated with decreased birthweight (OR=1.3/kg) rather than prematurity, and with exotropia (OR=3.3), but not ethnicity.
Conclusions: :
There is discordance among the definitions of anisometropia and their associated risk factors. Except for the association of strabismus with anisometropia, the association of previously published risk factors (e.g. family history, prematurity, CP) with anisometropia is notably lacking in our study.
Keywords: clinical (human) or epidemiologic studies: risk factor assessment • refractive error development