The progreion of refractive error in chool-age children: hunyi ditrict, China

PURPOE: To ae the progreion of refractive error and the incidence of myopia in chool-age children in the hunyi Ditrict of Beijing, China. DEIGN: A longitudinal cohort tudy. METHOD: A population-baed ample of 4,662 children initially examined in 1998 at age 5 to 13 year wa reexamined between eptember and November, 2000. Refractive error wa meaured under cycloplegia with autorefraction. Age, ex, and baeline refractive error were evaluated a rik factor for progreion. REULT: In 28.5 month, the average change in refractive error wa −0.42 diopter (tandard deviation, 0.68) in right eye. Myopic hift of refractive error wa aociated with female ex, older age, and higher myopic or hyperopic refractive error at baeline. The average change in atigmatic error wa eentially zero, with ignificant change in both direction more likely among thoe with higher baeline atigmatim. Finding were imilar for left eye. The cumulative incidence of myopia, defined a a pherical equivalent refractive error of −0.50 diopter or more in either eye, among initial emmetrope and hyperope wa 14.1% (95% confidence interval [CI], 11.8%–16.5%) for male and 23.5% (95% CI, 20.8%–26.1%) for female ubject. Myopia incidence increaed ixfold to evenfold between baeline age 5 and 12, before decreaing at age 13, for both male and female ubject. CONCLUION: In the deign of cot-effective program for the periodic creening and treatment of uncorrected refractive error, children initially found to require refractive correction hould be targeted for relatively frequent recreening, a hould girl and older children. Further tudy i required to better undertand environmental and genetic rik factor for myopia development and progreion.