Socioeconomic disparities in the distribution of children with hypermetropia at 7 years of age

Abstract

Abstract: : Purpose: Hypermetropia is a common refractive error in preschool and early school aged children and is a risk factor for strabismus and amblyopia. We present descriptive data from an ongoing birth cohort study, on associations between the presence of hypermetropia in children at the age of 7 years and various socioeconomic characteristics. Methods: All children participating in an ongoing birth cohort study were invited to an assessment at the age of 7 ½, where a detailed visual examination was carried out, including non–cycloplegic autorefraction. Children were categorized as hypermetropic if the spherical equivalent autorefraction result for their right eye was > +1.0 D. Prospectively collected data on demographic, physical and lifestyle characteristics were also included. Results: Of 8001 children with a usable autorefraction result for their right eye, 587 (7.3%) were hypermetropic. Significant univariate associations existed between hypermetropia and lower maternal social class (p < 0.001), council (state supported) housing rather than owner/occupied (p = 0.003), shorter duration of breast–feeding (p < 0.001), lower maternal consumption of oily fish during pregnancy (p = 0.003), a positive family history of strabismus/amblyopia (p < 0.001) and parental self–report of hypermetropia (p < 0.001). In multivariate analysis, the independent associations were between hypermetropia and being breast–fed for less than 4 months (p < 0.001); having a mother who ate oily fish less than once every 2 weeks (p < 0.01); having a positive family history of strabismus/amblyopia (p < 0.001) and parental long–sightedness (p < 0.001). Conclusions: Children with hypermetropia at the age of 7 ½ years were more likely to come from less socioeconomically advantaged families than children without hypermetropia. As hypermetropic children are at greater risk of strabismus or amblyopia, this demographic information is important to consider when planning paediatric ophthalmic services for the screening and/or treatment of common visual defects. The multivariate analyses suggest that duration of breast–feeding, and maternal intake of oily fish may be important underlying factors. These novel observations may suggest new directions for research into the pathogenesis of hypermetropia.

Keywords: hyperopia • clinical (human) or epidemiologic studies: prevalence/incidence • emmetropization