title: Prevalence of eye diseases and causes of visual impairment in school-aged children in Western China.
abstract: BACKGROUND
  The present study investigated the prevalence of refractive error, visual impairment, and eye diseases in school-aged children in western China.
  
  
  METHODS
  The survey was done in a representative county (Yongchuan District, Chongqing Municipality) of western China. Cluster random sampling was used to select children aged 6 to 15 years. We conducted door-to-door surveys and eye examinations including optometry, stereoscopic vision test, eye position and eye movement, slit lamp examination of the anterior segment, retinoscopy, and fundus examination after cycloplegia with 1% cyclopentolate.
  
  
  RESULTS
  Among 3469 children, data were available for 3079 (88.76%). The prevalences of eye diseases were, in descending order, refractive error (20.69%; 637/3079), conjunctivitis (11.76%; 362/3079), amblyopia (1.88%; 58/3079), color vision defect (0.52%; 16/3079), keratitis (0.36%; 11/3079), strabismus (0.29%; 9/3079), cataract (0.23%; 7/3079), pathologic myopia (0.19%; 6/3079), and ocular trauma (0.13%; 4/3079). The prevalence of corneal leucoma, corneal staphyloma, optic neuropathy, macular degeneration, and myelinated nerve fibers was 0.03% (1/3079) for each. The prevalence of visual impairment was 7.70% (237/3079), and the major causes of visual impairment were uncorrected refractive error (86.08%; 204/237), amblyopia (9.70%; 23/237), pathologic myopia (1.27%; 3/237), congenital cataract (0.42%; 1/237), and others (2.11%; 5/237).
  
  
  CONCLUSIONS
  Among school-aged children in a less developed area of western China, refractive error was the most prevalent eye disorder, and uncorrected refractive error was the main cause of visual impairment.
authors: Department of Ophthalmology, Children's Hospital, Chongqing Medical University, People’s Republic of China.
authors: Lian-Hong
authors: LH
authors: Pi
authors: Lin
authors: L
authors: Chen
authors: Qin
authors: Q
authors: Liu
authors: Ning
authors: N
authors: Ke
authors: Jing
authors: J
authors: Fang
authors: Shu
authors: S
authors: Zhang
authors: Jun
authors: J
authors: Xiao
authors: Wei-Jiang
authors: WJ
authors: Ye
authors: Yan
authors: Y
authors: Xiong
authors: Hui
authors: H
authors: Shi
authors: Xi-Yuan
authors: XY
authors: Zhou
authors: Zheng-Qin
authors: ZQ
authors: Yin
mesh_terms: D000293:Adolescent; D002648:Child; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D005128:Eye Diseases / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D015995:Prevalence; D012030:Refractive Errors / Q000150:complications / Q000453:epidemiology; D014786:Vision Disorders / Q000453:epidemiology / Q000209:etiology