Relationship of Hyperopia with Amblyopia, Strabismus, and Stereoacuity in Preschool Children

Abstract

Purpose: : To investigate the relationship between hyperopia >3.25D and amblyopia, strabismus, and stereoacuity among Head Start Preschoolers.

Methods: : 3- to 5-year old children (n=4040) underwent a comprehensive vision examination including monocular visual acuity (VA) testing, cover testing, and cycloplegic refraction during Phases I (A&B) and II of the Vision In Preschoolers (VIP) study. VA was tested with habitual correction, if any, and was retested with full cycloplegic correction when (1) VA was worse than 20/50 for 3-year-olds or 20/40 for 4- to 5-year-olds or a child showed an interocular acuity difference (IOD) ≥ 2 lines; AND (2) cycloplegic refraction showed hyperopia ≥ 2.0 D, myopia ≥ -0.5 D, or astigmatism ≥ 1.0 D in either eye. Stereoacuity testing (Stereo Smile) also was performed on 2898 children during Phases IB and II. Hyperopia was classified into 3 levels of severity: group 1= ≥+5.00D, group 2= >+3.25D to <+5D with spherical equivalent (SE) >0.5D, and group 3 = >+3.25D to <+5D with SE<0.5D.

Results: : Children with hyperopia >3.25D (N=466) had a significantly higher proportion of amblyopia (35% vs. 2.8%, p < 0.001) and strabismus (17% vs. 2.2%, p < 0.001) with a higher proportion of each associated with more severe levels of hyperopia (amblyopia: 13.3% (group 3) to 52.8% (group 1), strabismus: 8.4% (group 3) to 32.9% (group 1), p < 0.001 for both). Odds of amblyopia increased by 18.1 and odds of strabismus increased by 9.13 times with the presence of hyperopia. The median stereoacuity of nonstrabismic children with hyperopia (N=290) (240") was significantly worse than that of children without hyperopia (60") (p<0.001) and more severe levels of hyperopia were associated with worse stereoacuity (120" for groups 2 and 3, 480" for group 1, p<0.001).

Conclusions: : The presence and magnitude of hyperopia among preschoolers was associated with an increased proportion of amblyopia and strabismus and with worse stereoacuity even among non-strabismic children.

Keywords: hyperopia • amblyopia • strabismus