title: Disordered sleep and myopia risk among Chinese children.
abstract: OBJECTIVE
  Disordered sleep and myopia are increasingly prevalent among Chinese children. Similar pathways may be involved in regulation of both sleep cycles and eye growth. We therefore sought to examine the association between disordered sleep and myopia in this group.
  
  
  METHODS
  Urban primary school children participating in a clinical trial on myopia and outdoor activity underwent automated cycloplegic refraction with subjective refinement. Parents answered questions about children's sleep duration, sleep disorders (Children's Sleep Habits Questionnaire [CSHQ]), near work and time spent outdoors.
  
  
  RESULTS
  Among 1970 children, 1902 (96.5%, mean [standard deviation SD] age 9.80 [0.44] years, 53.1% boys) completed refraction and questionnaires. Myopia < = -0.50 Diopters was present in both eyes of 588 (30.9%) children (1329/3804 = 34.9% of eyes) and 1129 children (59.4%) had abnormal CSHQ scores (> 41). In logistic regression models by eye, odds of myopia < = -0.50D increased with worse CSHQ score (Odds Ratio [OR] 1.01 per point, 95% Confidence Interval [CI] [1.001, 1.02], P = 0.014) and more night-time sleep (OR 1.02, 95% CI [1.01, 1.04, P = 0.002], while male sex (OR 0.82, 95% CI [0.70, 0.95], P = 0.008) and time outdoors (OR = 0.97, 95% CI [0.95, 0.99], P = 0.011) were associated with less myopia. The association between sleep duration and myopia was not significant (p = 0.199) for total (night + midday) sleep.
  
  
  CONCLUSIONS
  Myopia and disordered sleep were both common in this cohort, but we did not find consistent evidence for an association between the two.
  
  
  BACKGROUND
  clinicaltrials.gov NCT00848900.
authors: State Key Laboratory of Ophthalmology and Division of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Zhongqiang
authors: Z
authors: Zhou
authors: State Key Laboratory of Ophthalmology and Division of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China; ARC Centre of Excellence in Vision Science, Research School of Biology, Australian National University, Canberra, Australia.
authors: Ian G
authors: IG
authors: Morgan
authors: State Key Laboratory of Ophthalmology and Division of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Qianyun
authors: Q
authors: Chen
authors: State Key Laboratory of Ophthalmology and Division of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Ling
authors: L
authors: Jin
authors: State Key Laboratory of Ophthalmology and Division of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors: Mingguang
authors: M
authors: He
authors: State Key Laboratory of Ophthalmology and Division of Preventive Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China; ORBIS International, New York, New York, United States of America.
authors: Nathan
authors: N
authors: Congdon
mesh_terms: D044466:Asian People / Q000706:statistics & numerical data*; D002648:Child; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003710:Demography; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D009216:Myopia / Q000150:complications* / Q000453:epidemiology* / Q000503:physiopathology; D016032:Randomized Controlled Trials as Topic; D012030:Refractive Errors / Q000150:complications / Q000453:epidemiology / Q000503:physiopathology; D012307:Risk Factors; D012893:Sleep Wake Disorders / Q000150:complications* / Q000453:epidemiology* / Q000503:physiopathology; D011795:Surveys and Questionnaires; D014792:Visual Acuity