A Longitudinal Study of Lifestyle Factors and Biometric Development in Children of a Regional Population

Abstract

[DOphSc - Doctor of Opthalmic Science] Uncorrected refractive error is one of the leading causes of blindness worldwide, occurring due to mismatch between the axial length of the eye and its refractive power. During emmetropisation, environmental influences may interrupt the coordinated growth of the eye leading to refractive error in adulthood. Elevated prevalence of myopia has led to the majority of studies focussing primarily on the risk factors leading to this condition. While no single factor has proven to be dominant, it is becoming clearer that these factors may compound, elevating risk. Studies on hyperopia and astigmatism are rarer, and understanding of the mechanisms behind these conditions is relatively poor. Interaction and modulation of the emmetropisation process represents a significant tool for the reduction of refractive error. To investigate the factors that may influence emmetropisation, cross sectional and longitudinal data were collated for 58 children aged 5 to 12 years in a regional Australian population. Mean axial length growth over 12 months for the cohort was 0.09 (±0.06), anterior chamber depth growth was 0.03 (±0.06), central corneal thickness change was −1.18 (±5.36). Refractive error in the longitudinal study was stable across the study period for hyperopia (7.89%), decreased for astigmatism (18.42%) at test 1 to 13.16% at test 2), and increased for myopia (5.26% at test 1 to 7.89% at test 2). Mean change in spherical equivalent refractive error over 12 months was −0.12 (±0.33) with a minimum of −0.93 and a maximum of +0.69. Axial length and spherical equivalent refractive error exhibited change across the study period in line with published values, anterior chamber depth for the cohort tended to be greater those indicated in normative models. The results from this lifestyle survey reinforce the conclusions of published data with respect to the influence of outdoor activities as a positive influence in emmetropisation.