Purpose
To evaluate the prevalence and characteristics of astigmatism in Chinese, Hispanic, Indian, Malay, Nepali and African children from eight sites of the multi-country Refractive Error Study in Children (RESC).
Methods
Among 46,260 children enumerated, cycloplegic (1% cyclopentolate) auto-refraction and a reliable visual acuity measurement were performed on 37,650 children of population-based, random cluster samples aged 5-15 in the RESC study.
Results
The prevalence of astigmatism (defined as <=-0.75 DC in the right eye) was 13.3% (95% confidence interval [CI]: 12.5%-14.0%) of all children with significant variation across ethnic groups after adjusted for confounders (p<0.001): 17.2% of Chinese, 8.22% of Indian, 12.2% of Malay, 3.32% of Nepali, 27.0% of Hispanic and 8.81% of African. The Guangzhou Chinese children (26.3%) had higher astigmatism prevalence than did the Shunyi Chinese children (9.53%). The Indian children in Delhi (9.24%) had higher prevalence than in India (5.78%). The prevalence of astigmatism decreased from 18.4% of 5-6 years old group into 11.65% of 10-12 years old group and then increased to 14.1% of 13-15 years. Higher astigmatism prevalence was associated with younger age (odds ratio [OR] =0.98, p=0.001), Female genders (OR=1.11, p=0.003), absolute spherical equivalent (OR=1.67, p<0.001). Astigmatism was predominantly oblique (cylinder between 16° to 75° or 106° to 165°; 44.8%, 95%CI: 44.0%-45.6%) and with-the-rule (WTR, cylinder between 0° to 15° or 166° to 180°; 40.2%, 95%CI: 39.1-41.3). Children with astigmatism had significantly more visual impairment (uncorrected visual acuity<=6/12) than did the children with non-astigmatism (OR=4.60, 95%CI: 4.10-5.16).
Conclusions
Astigmatism had a strong correlation with age, gender, spherical equivalent, ethnicity and site. Astigmatism was more common in Spanish and Chinese children. Children with astigmatism are more likely to have visual impairment.
Keywords: 428 astigmatism •
677 refractive error development