Abstract
Purpose:
To determine whether uncorrected hyperopic (≥3 to ≤6 diopters (D)) 4- or 5-year-old children without strabismus or amblyopia perform worse on an assessment of literacy (Test of Preschool Early Literacy [TOPEL]) than comparable emmetropic children.
Methods:
Children aged 4 or 5 who were attending preschool or kindergarten and who had not previously worn correction for refractive error were enrolled. Children with an Individualized Education Program (IEP) for development, educational, or behavioral issues were excluded. Vision examination with cycloplegic refraction was performed to confirm the presence of either hyperopia (≥3.0D to ≤6.0D in the most hyperopic meridian of at least one eye with astigmatism ≤1.5D and anisometropia ≤1.0D) or emmetropia (hyperopia ≤1.0D, astigmatism <1.0D, anisometropia <1.0D, and myopia <1.0D). Threshold visual acuity and cover testing were performed to rule out presence of amblyopia or strabismus. The TOPEL, composed of Print Knowledge, Definitional Vocabulary, and Phonological Awareness subtests, was administered by trained examiners.
Results:
Four hundred ninety-two children (244 hyperopes and 248 emmetropes) participated (mean age 58 months; mean±SD spherical equivalent refractive error +3.47D±0.81 in hyperopes and +0.37D±0.50 in emmetropes). The majority of children (89%) were in Head Start. The overall mean±SD TOPEL raw score was 86.6±23.2. The mean TOPEL score in hyperopic children was significantly lower than in emmetropic children (-5.9, 95% confidence interval [-10.0, -1.8], p=0.005). After adjustment for age, race/ethnicity, and parent/caregiver's education the mean difference between hyperopes and emmetropes was -4.3 (-7.7, -0.89),(p=0.01) for TOPEL overall,-2.4 (-4.1, -0.6), (p=0.007) for Print Knowledge, -1.6 (-3.3, 0.2), (p=0.08) for Definitional Vocabulary, and -0.3 (-1.1, 0.4), (p=0.39) for Phonological Awareness. For children with moderate hyperopia (+3.0 to 6.0D), the magnitude of hyperopia was not related to the TOPEL score (p=0.75).
Conclusions:
Uncorrected hyperopia in 4- to 5-year-old children enrolled in preschool or kindergarten is associated with significantly worse performance on a test of early literacy (TOPEL). In addition to remedial educational intervention, these children may benefit from preventive correction of refractive error, however, the effect of this intervention has not yet been evaluated.