Abstract
Purpose: :
To report the prevalence and incidence of refractive error in the SCES adolescent cohort, which includes children from the baseline Sydney Myopia Study (SMS) and its follow-up, the Sydney Adolescent Vascular Eye Disease Study (SAVES).
Methods: :
SMS was a randomly selected cross-sectional study of 2 age samples, mean ages 6.7 and 12.7 years, with 1735 and 2353 children respectively. In 2008-10, SAVES re-examined students from the SMS sample. A comprehensive ocular examination included cycloplegic (1% cyclopentolate) autorefraction was performed at baseline and follow-up. Spherical equivalent was calculated for the right eye, myopia was defined as ≤-0.50, hyperopia ≥+2.00. The studies had institutional ethical approval and adhered to the tenants of the Declaration of Helsinki.
Results: :
Of the younger sample, 866 children were re-tested (49.9%, mean age 12.7 years). Of these, 9.5% had developed myopia, an annual incidence rate of 1.7%. At follow-up, in the children of European Caucasian (EC) ethnicity (600), 4.0% had become myopic (annual incidence 0.7%), with a final prevalence of myopia of 4.4%. In those of East Asian (EA) ethnicity (141) 35.1% had become myopic (annual incidence 6.6%), giving a final prevalence of 37.1%, significantly higher than in EC children of the same age (p≤0.0001). In the older sample, 1148 were re-tested (48.8%, mean age 17.3 years) 8.4% had become myopic (annual incidence 2.1%). In those of EC ethnicity (689), 6.5% had become myopic, giving a final prevalence of 11.0%. In contrast 12.7% (238) of the EA children had become myopic, giving a final prevalence of 43.9%. Annual incidence rates were 1.6% and 3.2%, respectively.
Conclusions: :
The prevalence of myopia remained low at follow-up in Australian children of EC origin. In children of EA origin, the prevalence of myopia was higher than in children of EC origin, but lower than in comparable cohorts from EA cities. Annual incidence rates were higher in the older cohort for children of EC origin than the younger cohort. In contrast, they were higher in the younger cohort in children of EA origin, which raises concerns about their potential to develop high myopia and its consequent pathologies in the future.
Keywords: refractive error development • myopia