title: The effectiveness of progressive addition lenses on the progression of myopia in Chinese children.
abstract: OBJECTIVE
  To evaluate the effectiveness of progressive addition lenses (PALs), with a near addition of +1.50 D, on the progression of myopia in Chinese children.
  
  
  METHODS
  We enrolled 178 Chinese juvenile-onset acquired myopes (aged 7-13 years, -0.50 to -3.00 D spherical refractive error), who did not have moderately or highly myopic parents, for a 2-year prospective study. They were randomly assigned to the PAL group or single vision (SV) group. Primary measurements, which included myopia progression and ocular biometry, were performed every 6 months. Treatment effect was adjusted for important covariates, by using a multiple linear regression model.
  
  
  RESULTS
  One hundred and forty-nine subjects (75 in SV and 74 in PAL) completed the 2-year study. The myopia progression (mean +/- S.D.) in the SV and PAL groups was -1.50 +/- 0.67 and -1.24 +/- 0.56 D, respectively. This difference of 0.26 D over 2 years was statistically significant (p = 0.01). The lens type (p = 0.02) and baseline spherical equivalent refraction (p = 0.05) were significant contributing factors to myopia progression. Mean increase in the depth of vitreous chamber was 0.70 +/- 0.40 and 0.59 +/- 0.24 mm, respectively. This difference of 0.11 mm was statistically significant (p = 0.04). Age (p < 0.01) was the only contributing factor to the elongation of vitreous chamber. Different near phoria (p < 0.01) and gender (p = 0.02) caused different treatment effects when wearing SV lenses. However, there were no factors found to influence the treatment effect of wearing PALs.
  
  
  CONCLUSIONS
  Compared with SV lenses, myopia progression was found to be retarded by PALs to some extent in Chinese children without moderately or highly myopic parents, especially for subjects with near esophoria or females.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Zhikuan
authors.initials: Z
authors.lastname: Yang
authors.forename: Weizhong
authors.initials: W
authors.lastname: Lan
authors.forename: Jian
authors.initials: J
authors.lastname: Ge
authors.forename: Wen
authors.initials: W
authors.lastname: Liu
authors.forename: Xiang
authors.initials: X
authors.lastname: Chen
authors.forename: Linxin
authors.initials: L
authors.lastname: Chen
authors.forename: Minbin
authors.initials: M
authors.lastname: Yu
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D018450:Disease Progression; D005139:Eyeglasses; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D009216:Myopia / Q000208:ethnology / Q000503:physiopathology* / Q000628:therapy*; D012737:Sex Factors; D016896:Treatment Outcome