Incidence and Progression of Astigmatism in Singaporean Children

Tong, Louis; Saw, Seang‐Mei; Lin, Yu; Chia, Kee‐Seng; Koh, David; Tan, Donald

doi:10.1167/iovs.04-0492

Cited by 33 publications

(30 citation statements)

References 10 publications

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“…A finding that the magnitude of ATR internal astigmatism increases with increasing WTR keratometric astigmatism, or decreases with decreasing keratometric astigmatism, could reflect an active process of compensation and explain why refractive astigmatism tends to remain stable in Tohono O'odham children, as well as other populations of children. [12][13][14] Many studies have noted a ''compensation'' of corneal astigmatism by internal astigmatism, and a similar observation has been reported for other aberrations. 11,[15][16][17][18][19][20][21] A finding that changes in magnitude of ATR internal astigmatism are not correlated with changes in keratometric astigmatism would suggest that the ''compensation'' observed in Tohono O'odham preschoolers is reflective of a passive compensation resulting from a constant amount of internal ATR astigmatism that, in this population of predominantly WTR astigmats, results in a reduction in the total astigmatism.…”

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confidence: 55%

Longitudinal Change and Stability of Refractive, Keratometric, and Internal Astigmatism in Childhood

Harvey¹,

Miller²,

Twelker³

et al. 2014

Investigative Ophthalmology & Visual Science

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PURPOSE. To assess longitudinal change in refractive, keratometric, and internal astigmatism in a sample of students from a population with a high prevalence of with-the-rule (WTR) astigmatism and to determine the optical origins of changes in refractive astigmatism. METHODS.A retrospective analysis of longitudinal measurements of right eye refractive and keratometric astigmatism in Tohono O'odham Native American children was conducted. Changes in refractive and keratometric astigmatism per year were compared in a younger cohort (n ¼ 1594, 3 to <11 years old) and an older cohort (n ¼ 648, 11 to <19 years old). Data were analyzed in clinical notation (Cyl) and vector notation (J0, J45). RESULTS.On average, refractive astigmatism (means: 1.19 diopters [D] Cyl, þ0.54 J0, þ0.03 J45) resulted primarily from WTR corneal astigmatism (means: þ0.85 J0, À0.02 J45) and against-the-rule (ATR) internal astigmatism (means: À0.31 J0, þ0.05 J45). Mean longitudinal changes in astigmatism were statistically significant (younger cohort À0.02 D/y Cyl; older cohort þ0.06 D/y Cyl). In the younger cohort, astigmatism decreased with age in low and moderate astigmats (<3.00 D) and increased with age in high astigmats ( ‡3.00 D). In the older cohort, astigmatism increased with age across all levels of astigmatism. Longitudinal changes in keratometric and internal astigmatism were negatively correlated in both cohorts.CONCLUSIONS. Cross-sectional data suggest the presence of a constant ATR contribution from internal astigmatism (0.60 D Cyl) that is close to the 0.50 D ATR constant reported by Javal and others. Highly astigmatic 3-to <11-year-old children and children older than age 11 years show a small (not clinically significant) increase in astigmatism with age. A negative correlation between changes in keratometric astigmatism and internal astigmatism suggests an active compensation that may contribute to the stability of astigmatism in Tohono O'odham children.Keywords: astigmatism, refractive error development, children, Native American R esearch conducted over the past 15 years has yielded a large longitudinal database on refractive development in Tohono O'odham children. There is a high prevalence of astigmatism among elementary school children who are members of this Native American tribe.1-4 The high prevalence of refractive astigmatism in Tohono O'odham children is present in infancy and persists at least through elementary school. 1,2,4-7 A longitudinal study of corneal astigmatism in 960 Tohono O'odham children aged 6 months through 7 years showed that in early development (6 months to <3 years), astigmatism decreased in children with high astigmatism (À0.37 diopters [D]/y) and remained stable in children with little or no astigmatism (þ0.05 D/y).7 From age 3 through 7 years, astigmatism decreased in children with both high astigmatism (À0.11 D/y) and low/no astigmatism (À0.03 D/y). 7 A detailed account of changes in astigmatism beyond age 7 years in this population has not yet been reported. However, a recent report on change...

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mentioning

confidence: 55%

Longitudinal Change and Stability of Refractive, Keratometric, and Internal Astigmatism in Childhood

Harvey¹,

Miller²,

Twelker³

et al. 2014

Investigative Ophthalmology & Visual Science

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“…Additionally, around one third of Singaporean children are astigmatic, with 1 in 10 having cylinder power of 1.00diopter (D) or more. 11 The incidence of refractive error in Singaporean teenagers increases to 74% for myopia and 59% for astigmatism. 12 Risk factors for the high incidence of myopia include school grades, near work activity, ethnicity, and sex.…”

mentioning

confidence: 99%

Contact Lenses in Pediatrics Study in Singapore

Lim¹,

Moody²,

Tan³

et al. 2009

Eye &Amp; Contact Lens: Science &Amp; Clinical Practice

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“…Tong et al found an incidence rate of 11.5% (cylindrical power of 1.0 D or more). Only 8.3% of WTR children converted to ATR astigmatism whereas 41.2% of ATR astigmatism converted to WTR astigmatism in the age group 7-9 years [14].…”

Section: Discussionmentioning

confidence: 90%

“…It is generally accepted that ATR astigmatism is common in children under 4.5 years of age and this gradually changes to WTR astigmatism in older children [1,4,6,7,10,11,14]. Dobson et al reported that ATR astigmatism was 2.5 times more common than WTR astigmatism in children <3.5 years of age, whereas WTR astigmatism was three times more common than ATR astigmatism in children >5.5 years of age (up to 9.5 years) [6].…”

Section: Discussionmentioning

confidence: 99%