title: Prevalence of retinitis pigmentosa in urban and rural adult Chinese: The Beijing Eye Study.
abstract: OBJECTIVE
  To determine the prevalence of retinitis pigmentosa in the elderly Chinese population.
  
  
  METHODS
  The Beijing Eye Study is a population-based, cross-sectional cohort study and included 4439 subjects out of 5324 subjects invited to participate (response rate 83.4%) with an age of 40+ years. Readable fundus photographs were available for 4027 (90.7%) subjects. Diagnostic criteria for retinitis pigmentosa were visual field defects on frequency doubling perimetry, typical ophthalmoscopic abnormalities such as retinal pigment deposits, retinal arteriole attenuation, and pigment epithelial atrophy, and no other reason for perimetric defects and fundus abnormalities.
  
  
  RESULTS
  Retinitis pigmentosa was diagnosed in four subjects (all men). Its prevalence was 0.099+/-3.15% (95% CI: 0.00, 0.2).
  
  
  CONCLUSIONS
  Retinitis pigmentosa with typical fundus appearance and functional loss may be present in about 1 out of 1000 elderly Chinese in Northern China. Calculated for the whole population in China, the figure would be 1.3 million patients with retinitis pigmentosa.
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital University of Medical Science, Beijing, China.
authors.forename: L
authors.initials: L
authors.lastname: Xu
authors.forename: L
authors.initials: L
authors.lastname: Hu
authors.forename: K
authors.initials: K
authors.lastname: Ma
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: J B
authors.initials: JB
authors.lastname: Jonas
mesh_terms: D000328:Adult; D044466:Asian People / Q000208:ethnology; D002681:China / Q000453:epidemiology; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012174:Retinitis Pigmentosa / Q000175:diagnosis / Q000208:ethnology*; D012424:Rural Population / Q000706:statistics & numerical data*; D014505:Urban Population / Q000706:statistics & numerical data*; D058609:Visual Field Tests; D014794:Visual Fields