Abstract
Purpose: :
To evaluate risk factors associated with decreased visual acuity (VA) in a population-based sample of African-American (AA) and Hispanic (H) preschool children.
Methods: :
AA and H children aged 30-72 months from 44 census tracts underwent cover testing, VA testing (HOTV), and cycloplegic refraction. VA retesting with correction was performed for interocular difference in VA (IOD) ≥ 2 lines with VA 20/32 or worse in 1 eye or decreased VA in either eye (worse than 20/50; worse than 20/40 if age ≥48 months). Associations between IOD or bilateral decreased VA (BDVA) and age, ethnicity, maternal age, gestational ethanol/tobacco, breast-feeding, prematurity, birth-weight, Down syndrome, strabismus/amblyopia family history, preschool/daycare attendance, and family income were assessed. Associations between IOD and spherical equivalent (SE)anisometropia, astigmatic anisometropia, and strabismus were also assessed, as were those between BDVA and bilateral hyperopia, bilateral myopia, and bilateral astigmatism (refractive errors defined as multi-level variables). Independent risk factors were identified and odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariate logistic regression analyses; OR were considered significant when the CI excluded 1.
Results: :
In the 3352 children studied, IOD was significantly associated with higher SE anisometropia (OR ≥ 6.5 for SE anisometropia levels ≥1D) and higher astigmatic anisometopia (OR ≥3.5 for J0/J45 differences ≥0.5 ), as well as with not attending preschool/daycare (OR 1.9), having esotropia (OR 5.1), and being Hispanic (OR 1.6). BDVA was associated with bilateral hyperopia (OR ≥21 for levels ≥5D, relative to <2D), bilateral astigmatism (OR ≥9.9 for levels ≥2D), and younger age group (OR ≥3.1).
Conclusions: :
Even moderately low levels of astigmatism and SE or astigmatic anisometropia are associated with deficits in best-corrected visual acuity. A prospective study is needed to confirm these associations, and further study is needed to determine whether early intervention for these moderate levels of refractive error would reduce the risk of amblyopia.
Keywords: amblyopia • clinical (human) or epidemiologic studies: risk factor assessment • visual acuity