Abstract

Purpose: To compare refraction and ocular biometry in European Caucasian children aged 6-7 years and 12-13 years living in Sydney, Australia and Northern Ireland. Methods: All children had a comprehensive eye examination, including cycloplegic (cyclopentolate 1%) autorefraction (Sydney; Canon RK-F1, Northern Ireland; Shin-Nippon SRW-5000) and ocular biometry (IOLMaster, Carl Ziess). Hyperopia was defined as a right spherical equivalent refraction (SER) of ≥+2.00 dioptres (D), myopia as ≤-0.50D and astigmatism as a cylindrical error of ≥1.00D.Results: The mean SER was similar at age 6-7 yrs (p=0.9), however, at 12-13 yrs, children in Northern Ireland had a significantly less hyperopic mean SER (+0.66D) than children in Sydney (+0.83D, p=0.008). The prevalence of myopia, hyperopia and astigmatism was significantly greater in Northern Ireland than Sydney at both ages (all p <0.03). The distribution of refraction was highly leptokurtic in both samples, but less so in Northern Ireland (kurtosis, 6-7yrs, 7.2; 12-13yrs, 5.9) than Sydney (6-7yrs, 15.0; 12-13yrs, 19.5). Conclusions: European Caucasian children in Northern Ireland have a greater prevalence of myopia, hyperopia and astigmatism when compared to children living in Sydney. Risk factors for myopia such as parental myopia, parental education, and educational standards do not appear to explain the differences. Further work on levels of nearwork and time spent outdoors is required.