Epidemiologic Study of Ocular Refraction among Schoolchildren in Taiwan in 1995
Resource
OPTOMETRY AND VISION SCIENCE v.76 n.5 pp.275-281
Journal
OPTOMETRY AND
Journal Volume
VISION
Journal Issue
n.5
Pages
275-281
Date Issued
1999
Date
1999
Author(s)
LIN, LUKE LONG-KUANG
HUNG, POR-TYING
HOU, PING-KANG
SHIH, YUNG-FENG
Abstract
Purpose. In order to understand and update the prevalence of myopia in Taiwan, a nationwide survey was performed in 1995 . Methods. We stratified the cluster sampling by developmental grading of the city, using a size proportional to the population, Two cities were randomly selected from each city grading. The total number of students enrolled was 11,178, including 5,676 boys and 5,502 girls. The refractive status and corneal radius of each student were measured with an autorefractometer under cycloplegia and checked with retinoscopy, Axial length was measured with biometric ultrasound. Results. The myopic rate was from 12% at the age of 6, it increased to 56% at the age of 12, and then to 76% at the age of 15. A myopic rate of 84% was found for the age range of 16 to 18. The prevalence of high myopia (over -6.0 D) at the age of 18 was 20% in girls and 12% in boys. The mean refractive status became myopic at the age of 9, then increased to -3.92 D in girls and -2.71 D in boys at the age of 18. The increase of axial length is correspondent with the progression of myopia. The anterior chamber depth (ACD) was deeper with age and the severity of myopia, whereas the corneal curvature remained unchanged. The lens thickness became thinner from age 7 to 13, then it became thicker with age and the severity of myopia after age 15. The prevalence and degree of myopia in girls was more severe than in boys. Conclusions. The prevalence of myopia in Taiwan increased year by year. The increase in severity and prevalence of high myopia may be due to earlier onset.
Subjects
MYPOIA
REFRACTIVE STATUS
AXIAL LENGTH
LENS THICKNESS
CORNEAL CURVATURE