HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (11) Citing Articles via Google Scholar Google Scholar Articles by Huynh, S. C. Articles by Mitchell, P. Search for Related Content PubMed PubMed Citation Articles by Huynh, S. C. Articles by Mitchell, P.

Astigmatism and Its Components in 6-Year-Old Children

¹From the Centre for Vision Research, Department of Ophthalmology, and the Westmead Millennium Institute, University of Sydney, and the Vision Cooperative Research Centre, Sydney, Australia; the ²School of Applied Vision Sciences, Faculty of Health Sciences, University of Sydney, Sydney, Australia; the ³Research School of Biological Sciences and Centre for Visual Science, Australian National University, Canberra, Australia; and the ⁴Department of Statistics, Macquarie University, Sydney, Australia.

PURPOSE. The purpose of the present study was to report the prevalence of refractive (RA), corneal (CA), and internal astigmatism (IA) in a population of 6-year-old children; examine their variation with gender, ethnicity, and refraction; and examine the effects of gender, ethnicity, and spherical equivalent refraction on the relationship between CA and RA in this population.

METHODS. The Sydney Myopia Study is a population-based survey of refraction and eye health in 6-year-old children. A random cluster design was used to recruit children from schools across Sydney, Australia, during 2003 to 2004. Data collection used a detailed questionnaire and comprehensive eye examination. Keratometric and cycloplegic autorefraction data from right eyes were analyzed.

RESULTS. Of 2238 eligible children, 1765 (78.9%; 50.7% boys) had parental consent to participate. Overall prevalence of RA (1.0 diopter [D]) was 4.8% (95% confidence interval [CI] 3.8%–6.1%), CA (1.0 D) 27.7% (CI 23.8%–32.3%), and IA (1.0 D) 21.1% (CI 19.0%–23.5%). The RA axis was fairly evenly distributed, with predominance of oblique axis (39.1%; CI 35.9%–42.6%). CA axis was mainly with the rule (75.1%; CI 72.6%–77.8%), while IA axis was mainly against the rule (76.7%; CI 74.2%–79.3%). After adjustment for multiple variables, girls had significant, marginally greater mean CA and IA than boys. East Asian and South Asian children had significantly greater prevalence and mean RA and CA than European Caucasian children. There were no significant ethnic differences of mean IA. Compared to reference (spherical equivalent [SEq] 1.01–1.50 D), mean RA and CA increased significantly with more hyperopic and more myopic refractions. Mean IA was significantly greater only for hyperopic refractions (SEq > 2.00 D).

CONCLUSIONS. The prevalence of astigmatism found in this population of 6-year-old children was relatively low, and showed significant variation with ethnicity. The data suggest that emmetropization for RA occurs by a compensatory process between CA and IA.

This article has been cited by other articles:

				M. Dirani, A. Islam, S. N. Shekar, and P. N. Baird Dominant Genetic Effects on Corneal Astigmatism: The Genes in Myopia (GEM) Twin Study Invest. Ophthalmol. Vis. Sci., April 1, 2008; 49(4): 1339 - 1344. [Abstract] [Full Text] [PDF]

				R. H. Trivedi and M. E. Wilson Keratometry in Pediatric Eyes With Cataract Arch Ophthalmol, January 1, 2008; 126(1): 38 - 42. [Abstract] [Full Text] [PDF]

				S. C. Huynh, A. Kifley, K. A. Rose, I. G. Morgan, and P. Mitchell Astigmatism in 12-Year-Old Australian Children: Comparisons with a 6-Year-Old Population Invest. Ophthalmol. Vis. Sci., January 1, 2007; 48(1): 73 - 82. [Abstract] [Full Text] [PDF]