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Updated: Jun 15, 2026
The Measurement and Treatment of Suppression in Amblyopia
Published on: December 14, 2012
Prevalence of amblyopia and strabismus in young singaporean chinese children
Audrey Chia1, Mohamed Dirani, Yiong-Huak Chan
1Singapore National Eye Center, Singapore. wla_chia@yahoo.com
Insights
This study found amblyopia prevalence of 1.19% and strabismus prevalence of 0.80% in young Singaporean Chinese children. Refractive errors were the main cause of amblyopia, and intermittent exotropia was common.
Area of Science:
- Ophthalmology
- Pediatric Ophthalmology
- Public Health
Background:
- Amblyopia and strabismus are common causes of visual impairment in children.
- Understanding the prevalence of these conditions in diverse populations is crucial for early detection and intervention.
- Previous studies have reported varying prevalence rates globally.
Purpose of the Study:
- To determine the prevalence of amblyopia and strabismus in young Singaporean Chinese children.
- To identify the primary causes and types of amblyopia and strabismus in this cohort.
- To compare findings with international data.
Main Methods:
- A cross-sectional study involving 3009 Singaporean children aged 6 to 72 months.
- Comprehensive eye examinations including cycloplegic refraction and visual acuity (VA) assessment.
- Standardized definitions for amblyopia (unilateral and bilateral) and strabismus were used.
Main Results:
- The prevalence of amblyopia was 1.19% (ages 30-72 months) and strabismus was 0.80% (ages 6-72 months).
- Refractive errors, particularly astigmatism, were the leading cause of amblyopia (85%).
- Exotropia was more common than esotropia (7:1 ratio), with intermittent exotropia being the most frequent type (63%).
Conclusions:
- The prevalence of amblyopia in young Singaporean Chinese children is comparable to other populations.
- The prevalence of strabismus appears lower than reported in other international studies.
- Early screening and intervention are vital for managing these pediatric eye conditions.
Abstract:
PURPOSE. To determine the prevalence of amblyopia and strabismus in young Singaporean Chinese children. METHODS. Enrolled in the study were 3009 Singaporean children, aged 6 to 72 months. All underwent complete eye examinations and cycloplegic refraction. Visual acuity (VA) was measured with a logMAR chart when possible and the Sheridan-Gardner test when not. Strabismus was defined as any manifest tropia. Unilateral amblyopia was defined as a 2-line difference between eyes with VA < 20/30 in the worse eye and with coexisting anisometropia (> or =1.00 D for hyperopia, > or =3.00 D for myopia, and > or =1.50 D for astigmatism), strabismus, or past or present visual axis obstruction. Bilateral amblyopia was defined as VA in both eyes <20/40 (in children 48-72 months) and <20/50 (<48 months), with coexisting hyperopia > or =4.00 D, myopia < or = -6.00 D, and astigmatism > or =2.50 D, or past or present visual axis obstruction. RESULTS. The amblyopia prevalence in children aged 30 to 72 months was 1.19% (95% confidence interval [CI], 0.73-1.83) with no age (P = 0.37) or sex (P = 0.22) differences. Unilateral amblyopia (0.83%) was twice as frequent as bilateral amblyopia (0.36%). The most frequent causes of amblyopia were refractive error (85%) and strabismus (15%); anisometropic astigmatism >1.50 D (42%) and isometropic astigmatism >2.50 D (29%) were frequent refractive errors. The prevalence of strabismus in children aged 6 to 72 months was 0.80% (95% CI, 0.51-1.19), with no sex (P = 0.52) or age (P = 0.08) effects. The exotropia-esotropia ratio was 7:1, with most exotropia being intermittent (63%). Of children with amblyopia, 15.0% had strabismus, whereas 12.5% of children with strabismus had amblyopia. CONCLUSIONS. The prevalence of amblyopia was similar, whereas the prevalence of strabismus was lower than in other populations.
