Preschool vision screening and reading ability at age 7

Abstract

Abstract: : Purpose: There has been great debate regarding the potential benefit of preschool vision screening. Few data are available on non–visual outcomes, associated either with visual defects or of interventions designed to detect or treat them. Such data are needed to give a full picture of the value or otherwise of preschool vision screening. Methods: Over 6000 children in an ongoing birth cohort study had a standardized reading assessment and a visual assessment at the age of 7 ½ years. Reading scores were compared in those children who had been offered preschool vision screening and those who had not. Two subgroups of interest were specifically investigated; children previously treated for amblyopia and children with hypermetropia (based on autorefraction at 7 ½). The results were adjusted for demographic factors including maternal education and sex of the child. Results: Of 6080 children, 1516 had been offered preschool vision screening and 1018 (67%) had received it. Children who had been offered screening performed better in the reading test than children who hadn’t (p = 0.036). There were no significant differences between screening groups for amblyopic children. However, the adjusted mean reading scores for hypermetropic (spherical equivalent of right eye > 1.0 D) children were 28.4 words vs. 26.0 words in the offered screening vs. not offered screening groups respectively (p = 0.036). In post hoc analyses, hypermetropic children who did not wear glasses for the reading test were 4 times as likely to be in the lowest quintile (20%) for reading if they were in the "not–offered" group, as compared with similar children in the "offered" group; adjusted OR 4.1 (95% CI: 1.5 to 11.5), p = 0.002. Conclusions: These data support the prior hypothesis that preschool vision screening is associated with better subsequent reading skills, for hypermetropic children. This may be because of a greater likelihood that hypermetropic children offered screening would be given spectacles if their refractive error affected their reading. These data suggest reading ability in hypermetropic children could be considered as an important outcome of a vision screening programme.

Keywords: screening for ambylopia and strabismus • hyperopia • reading