Young Hyperopes Lab Behind Emmetropes in Emergent Literacy Skills

Abstract

Abstract: : Purpose: To compare emergent literacy skills in uncorrected hyperopic and emmetropic children. Methods: Previously in a pilot study we had reported differences between hyperopes and emmetropes in emergent literacy tasks.¹ To ensure that differences found between hyperopes and emmetropes were not due to developmental or visuocognitive differences, for this study we added tests of visual–motor (Developmental test of Visual Motor Integration) and visual–perceptual skills (Test of visual perceptual skills, 2 subtests). Hyperopes (≥ 2D OU; N=13; aged 67±13 m) and emmetropes (≤ 1.75 D OU; N=19; aged 58±12 m) were recruited from a vision study and tested for visual acuity (VA; Cambridge Crowding cards, single and crowded letters) and administered three standardized tests (phonological awareness, letter/word reading skills, and receptive vocabulary), and an experimental test of visual orthographic skills. Parents also completed a survey of family demographics, developmental concerns and home literacy experiences. Results: Vision: There were no differences in single letter VA for hyperopes and emmetropes and crowded letters for the right eye. Crowding effects were observed for the left eye for hyperopes (F(30)=2.26, p=.03), with two of the hyperopes showing abnormal crowding (crowded VA/single VA). Literacy: Hyperopes lagged behind emmetropes in letter and word recognition ability (Mann–Whitney U=72, p=0.05), receptive vocabulary (Mann–Whitney U=55, p=0.01), and visual–orthographic discrimination (F(1, 29) =14.59, p = 0.03). The groups did not differ in phonological awareness skills (F(1, 29) =2.61, p = 0.39). Other variables: No statistically significant differences between the two groups were found for visual–motor or visual–perceptual skills, age, and some family variables known to contribute to emergent literacy skills. However, the emmetropic group came more from homes with two parents and higher income, and higher maternal education and reading skills than did the hyperopic group. Conclusions: 1. Hyperopic children show increased crowding effects and reduced performance on tests of letter and word recognition, receptive vocabulary, and visual–orthographic discrimination. 2. The observed lag in emergent literacy skills in spite of no notable differences in the visuocognitive domain² and general developmental and health area, suggests that the deficits of young hyperopes are complex. ¹Shankar,S, Evans, M.A., Ball, K, Saad, J, Butler, A, Bobier,W.R, 2004. ARVO abstract #4318. ²Atkinson, J, Anker, S, Nardini, M, Braddick, O. 2002. Strabismus, 10, 187–98

Keywords: hyperopia • visual acuity • reading