Aims To determine axial length (AL) elongation profiles in children aged 3–6 years in an Asian population.
Methods Eligible subjects were recruited from the Growing Up in Singapore Towards Healthy Outcomes birth cohort. AL measurement was performed using IOLMaster (Carl Zeiss Meditec, Jena, Germany) at 3 and 6 years. Anthropometric measurements at birth, cycloplegic refraction at 3 and 6 years, questionnaires on the children’s behavioural habits at 2 years and parental spherical equivalent refraction were performed. Multivariable linear regression model with generalised estimating equation was performed to determine factors associated with AL elongation.
Results 273 eyes of 194 children were included. The mean AL increased from 21.72±0.59 mm at 3 years to 22.52±0.66 mm at 6 years (p<0.001). Myopic eyes at 6 years had greater AL elongation (1.02±0.34 mm) compared with emmetropic eyes (0.85±0.25 mm, p=0.008) and hyperopic eyes (0.74±0.16 mm, p<0.001). The 95th percentile limit of AL elongation was 1.59 mm in myopes, 1.34 mm in emmetropes and 1.00 mm in hyperopes. Greater birth weight (per 100 g, β=0.010, p=0.02) was significantly associated with greater AL elongation from 3 to 6 years, while parental and other behavioural factors assessed at 2 years were not (all p≥0.08).
Conclusion In this preschool cohort, AL elongates at an average length of 0.80 mm from 3 to 6 years, with myopes demonstrating the greatest elongation. The differences in 95th percentile limits for AL elongation between myopes, emmetropes and hyperopes can be valuable information in identifying myopia development in preschool children.
- Child health (paediatrics)
Data availability statement
Data may be provided upon reasonable request, subject to approval by the local ethics board.
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Y-CT and CN are joint senior authors.
Twitter @Yih Chung Tham
Contributors Conceptualisation, methodology, validation: DC, CW, Y-SC, S-MS, Y-CT and CN. Data collection, data analysis and visualisation: DC and YCT. Manuscript creation: DC, CW, Y-CT. Critical review and supervision of manuscript: DC, CW, JL, C-HS, YL, VK, Y-SC, S-MS, CN and Y-CT. All authors read and approved the final manuscript. Y-CT accepts full responsibility for the work and/or the conduct of the study, had access to the data, and controlled the decision to publish.
Funding YCT is supported by the National Medical Research Council's Transition Award (NMRC/MOH/TA18nov-0002) and HPHSR Clinician Scientist Award (NMRC/MOH/ HCSAINV21nov-0001).
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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