Purpose To describe the profile and associations of anisometropia and aniso-astigmatism in a population-based sample of children MethodsThe NICER (Northern Ireland Childhood Errors of Refraction) study used a stratified random cluster design to recruit a representative sample of children from schools in NI. Examinations included cycloplegic (1% cyclopentolate) autorefraction and measures of axial length, anterior chamber depth and corneal curvature. ² tests were used to assess variations in the prevalence of anisometropia and aniso-astigmatism by age-group, with logistic regression used to compare odds of anisometropia and aniso-astigmatism with refractive status (myopia, emmetropia, hyperopia). Mann Whitney U-test was used to examine inter-ocular differences in ocular biometry. ResultsData from 661 white children aged 12-13 years (50.5% male) and 389 white children aged 6-7 years (49.6% male) are presented. The prevalence of anisometropia ≥1DS did not differ statistically significantly between 6-7-year-old (8.5%, 95% CIs 3.9-13.1) and 12-13-year-old children (9.4%, 95% CIs 5.9-12.9). The prevalence of aniso-astigmatism ≥1DC did not vary statistically significantly between 6-7-year-old (7.7%, 95% CIs 4.3-11.2) and 12-13-year-old children (5.6%, 95% CIs 0.5-8.1). Anisometropia and aniso-astigmatism were more common in 12-13-year children with hyperopia ≥+2DS. Anisometropic eyes had greater axial length asymmetry than non-anisometropic eyes; aniso-astigmatic eyes were more asymmetric in axial length and corneal astigmatism than eyes without aniso-astigmatism.ConclusionsIn this population there is a high prevalence of axial anisometropia and corneal/axial aniso-astigmatism, associated with hyperopia but whether these relations are causal is unclear. Further work is required to clarify the developmental mechanism behind these associations.
O'Donoghue, L., McClelland, JF., Logan, NS., Rudnicka, AR., Owen, CG., & Saunders, KJ. (2012). Profile of anisometropia and aniso-astigmatism in children: prevalence and association with age, ocular biometric measures and refractive status. Investigative Ophthalmology and Visual Science, 54(1), 602-608. https://doi.org/10.1167/iovs.12-11066