title: Generational difference of refractive error and risk factors in the Handan Offspring Myopia Study.
abstract: OBJECTIVE
  To report the refractive error difference (RED) between parents and their children, and its risk factors, in a rural area of China.
  
  
  METHODS
  Children (6-17 years) and their parents (36.2 ± 4.1 years) from the Handan Offspring Myopia Study (HOMS) were enrolled. Cycloplegic autorefraction (cyclopentolate 1%, Topcon KR8800) of the children and noncycloplegic autorefraction of their parents were assessed. A detailed vision-based questionnaire was also completed. Refractive error difference was defined as the difference between the parental spherical equivalent (SE) and their children's SE. Generational myopic shift was defined as the estimated RED when a child would be 18 years old according to a prediction model.
  
  
  RESULTS
  Three hundred fifty-six pairs of parents and 585 children were enrolled. The RED (median, quartiles) increased from -1.33 (-1.99, -0.98) diopters (D) in children aged 6 to 7 years to 0.81 (-0.16, 2.28) D in children aged 16 to 17 years. The children's SE was predicted to approach the parental SE at 14 years of age. Moreover, the children's estimated myopic shift would be 1.03 D. Multiple linear regression revealed that older children (β = 0.23 D/y, P < 0.0001) and girls (β = 0.24, P = 0.01) tended to have a higher RED.
  
  
  CONCLUSIONS
  In this rural Chinese population, the children's refraction was estimated to be similar to the parental refraction at 14 years of age. Moreover, the generational myopic shift was estimated to be approximately 1 D at 18 years of age. These data suggest that the generational difference reflects the increasing prevalence of myopia in the younger generation, which is likely due to changes in environmental exposure.
authors.affiliation: The Affiliated Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, Zhejiang, China Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Lab, Beijing, China.
authors.forename: Zhong
authors.initials: Z
authors.lastname: Lin
authors.affiliation: Handan Eye Hospital, Handan, Hebei, China.
authors.forename: Tie Ying
authors.initials: TY
authors.lastname: Gao
authors.affiliation: College of Optometry, Midwestern University, Glendale, Arizona, United States.
authors.forename: Balamurali
authors.initials: B
authors.lastname: Vasudevan
authors.affiliation: Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China.
authors.forename: Vishal
authors.initials: V
authors.lastname: Jhanji
authors.affiliation: Department of Biological and Vision Sciences, State University of New York College of Optometry, New York, New York, United States.
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Ciuffreda
authors.affiliation: Handan Eye Hospital, Handan, Hebei, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhang
authors.affiliation: Handan Eye Hospital, Handan, Hebei, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: The Affiliated Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, Zhejiang, China School of Environmental Science and Public Health, Wenzhou Medical University, Wenzhou, Zhejiang, China Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States.
authors.forename: Guang Yun
authors.initials: GY
authors.lastname: Mao
authors.affiliation: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Lab, Beijing, China.
authors.forename: Ning Li
authors.initials: NL
authors.lastname: Wang
authors.affiliation: The Affiliated Eye Hospital, School of Optometry and Ophthalmology, Wenzhou Medical University, Wenzhou, Zhejiang, China Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Lab, Beijing, China.
authors.forename: Yuan Bo
authors.initials: YB
authors.lastname: Liang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D008019:Life Style; D008297:Male; D009216:Myopia / Q000453:epidemiology / Q000235:genetics; D012030:Refractive Errors / Q000453:epidemiology / Q000235:genetics; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D014505:Urban Population / Q000706:statistics & numerical data
keywords: myopia; refractive error; risk factors