title: Prevalence and causes of visual field loss as determined by frequency doubling perimetry in urban and rural adult Chinese.
abstract: OBJECTIVE
  To determine prevalence and causes of visual field loss (VFL) as determined by frequency doubling perimetry in elderly Chinese individuals.
  
  
  METHODS
  Population-based, cross-sectional cohort study.
  
  
  METHODS
  The Beijing Eye Study included 4439 of 5324 subjects (83.4%) who were invited to participate with an age of 40+ years. Visual field was assessed by frequency doubling threshold perimetry. Main outcome measure was an abnormal visual field defined as at least one test location of reduced sensitivity.
  
  
  RESULTS
  Of the 4439 people who were examined, 4350 subjects (98.0%; 8617 eyes) provided measurement data by frequency doubling perimetry. In subjects aged 40 to 49 years, the most frequent cause for VFL was degenerative myopia followed by glaucoma, other optic nerve diseases, and cataract. In the subjects aged 60 to 69 years, the most frequent cause for VFL was cataract, followed by glaucoma and degenerative myopia. In the subjects aged 70+ years, the most frequent cause for VFL was glaucoma, followed by cataract and degenerative myopia. VFL was associated significantly with age (P < .001), myopic refractive error (P < .001), rural region (P = .001), low level of education (P = .01), degree of nuclear cataract (P < .001), and intraocular pressure (P < .001).
  
  
  CONCLUSIONS
  In contrast to Western countries, age-related macular degeneration and diabetic retinopathy play a minor role as a cause for VFL in China.
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Capital University of Medical Science, China.
authors.forename: Yaxing
authors.initials: Y
authors.lastname: Wang
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.forename: Jost B
authors.initials: JB
authors.lastname: Jonas
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000706:statistics & numerical data*; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D005128:Eye Diseases / Q000150:complications; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011446:Prospective Studies; D012424:Rural Population / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data*; D014786:Vision Disorders / Q000453:epidemiology* / Q000209:etiology; D058609:Visual Field Tests / Q000379:methods*; D014794:Visual Fields