Elsevier

Ophthalmology

Volume 109, Issue 11, November 2002, Pages 2065-2071
Ophthalmology

Article for CME credit
Component dependent risk factors for ocular parameters in Singapore Chinese children

https://doi.org/10.1016/S0161-6420(02)01220-4Get rights and content

Abstract

Objective

To examine the risk factors for variations in ocular biometry parameters in Singapore Chinese children, a population with a known high prevalence rate of myopia at an early age.

Design

Cross-sectional study.

Participants

Children aged 7 to 9 years (n = 1453) from three schools in Singapore.

Methods

The children underwent A scan biometry and cycloplegic autorefraction measurements. Questions were asked regarding number of books read per week, night lighting, and parental myopia.

Main outcome measures

Axial length, vitreous chamber depth, lens thickness, anterior chamber depth, refraction, and corneal curvature radius measurements were made.

Results

After controlling for several factors, the axial lengths were found to be longer and vitreous chambers deeper in children who were older, male, read more than two books per week, or taller, and those who had at least one parent who was myopic. In these models, children who read more than two books per week had axial lengths that were 0.17 mm longer and vitreous chambers that were 0.15 mm deeper compared with children who read two or fewer books per week. Anterior chambers were deeper in males and taller children, whereas corneal curvature was steeper in female, older, and shorter children.

Conclusions

Increases of axial length and vitreous cavity depth were associated with older age, being male, reading more than two books per week, increased height, and parental history of myopia. Of these risk factors, however, neither reading nor parental myopia history were associated with values for anterior chamber depth, corneal curvature, or lens thickness. These findings confirm that conventional risk factors for myopia associated with the vitreous cavity, but suggest that anterior segment parameters such as corneal curvature and lens thickness may be subject to unrelated postnatal growth control mechanisms.

Section snippets

Materials and methods

Entry data are reported for school children from three different parts of the island enrolled in the cohort study in 1999 and 2001. All children in grades one and two aged 7 to 8 years in an Eastern school (n = 660) and those in grades one to three aged 7 to 9 years in a Northern school (n = 1023) were invited to join the study in November 1999, whereas children in grades one to three in a Western school (n = 1230) were recruited in May 2001. Children who had serious medical conditions (n = 94)

Results

There were 749 boys (51.5%) and 704 girls (48.5%), ranging in age from 7 to 9 years. The prevalence rates of myopia in 7-, 8-, and 9-year-olds were 29.0% (95% confidence interval [CI], 25.5, 32.6), 34.7% (95% CI, 30.4, 39.0), and 53.1% (95% CI, 47.9, 58.4), respectively. The average AL was 23.3 mm (range, 21.4–27.2 mm), vitreous chamber depth was 16.2 mm (range, 14.5–19.8 mm), LT was 3.5 mm (range, 3.1–4.2 mm), corneal curvature radius was 7.7 mm (range, 7.2–8.6 mm), and refraction was +0.03 D

Discussion

In this study of young Singapore Chinese school children, several risk factors were associated with the different ocular component measurements. Although the myopic eye has a deeper anterior chamber and thinner lens, school myopia is predominantly axial in nature, and the primary contribution to increased AL is a deeper vitreous chamber. The deeper anterior chambers may reduce optically the effect of vitreous chamber deepening on myopia, perhaps as a result of an active emmetropization process.

References (26)

  • F.L. Ferris et al.

    New visual acuity charts for clinical research

    Am J Ophthalmol

    (1982)
  • D.A. Goss

    Nearwork and myopia

    Lancet

    (2000)
  • J.L. Zhao et al.

    Refractive error study in childrenresults from Shunyi District, China

    Am J Ophthalmol

    (2000)
  • D.O. Mutti et al.

    Myopiaan epidemic of possibilities?

    Optom Vis Sci

    (1999)
  • S.M. Saw et al.

    Epidemiology of myopia

    Epidemiol Rev

    (1996)
  • J. Wallman et al.

    Local retinal regions control local eye growth and myopia

    Science

    (1987)
  • K. Zadnik et al.

    Ocular predictors of the onset of juvenile myopia

    Invest Ophthalmol Vis Sci

    (1999)
  • N.A. McBrien et al.

    A longitudinal investigation of adult-onset and adult-progression of myopia in an occupational grouprefractive and biometric findings

    Invest Ophthalmol Vis Sci

    (1997)
  • B.C. Jiang et al.

    Vitreous chamber elongation is responsible for myopia development in a young adult

    Optom Vis Sci

    (1996)
  • L.L.K. Lin et al.

    Changes in ocular refraction and its components among medical students—a 5-year longitudinal study

    Optom Vis Sci

    (1996)
  • N.W.H. Tan et al.

    Temporal variations in myopia progression in Singaporean children within an academic year

    Optom Vis Sci

    (2000)
  • M.Z. Zhang et al.

    Refractive errors in Singapore and Xiamen, China—a comparative study in school children aged 6 to 7 years

    Optom Vis Sci

    (2000)
  • Stat Statistical Software: Release 7.0

    (2001)
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    Supported by the National Medical Research Council (NMRC; grant no.: SERI/MG/97-04/0005), Singapore, Republic of Singapore.

    1

    Dr. Stone is the recipient of a Research to Prevent Blindness Physician-Scientist Merit Award.

    2

    The authors have no commercial interests in the products or devices mentioned herein.

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