title: Prevalence and characteristics of primary angle-closure diseases in a rural adult Chinese population: the Handan Eye Study.
abstract: OBJECTIVE
  To investigate the prevalence and characteristics of primary angle-closure suspect (PACS), primary angle closure (PAC), and primary angle-closure glaucoma (PACG) in a rural population in China.
  
  
  METHODS
  In all, 6716 Han Chinese 30 years of age and older (5480 subjects 40 years of age and older) from 13 villages in Handan were randomly selected and completed an ophthalmologic examination, including visual acuity, intraocular pressure (IOP), slit-lamp examination, gonioscopy and stereoscopic photography, and visual field. PACS was defined as present if either eye had the posterior trabecular meshwork not visible for 180° or more on gonioscopy. PAC was present in an eye with PACS and peripheral anterior synechiae (PAS) and/or IOP ≥ 21 mm Hg, but without glaucomatous neuropathy (GON). PACG was defined as PAC with evidence of GON.
  
  
  RESULTS
  The standardized prevalences of PACG, PAC, and PACS were 0.5% (95% confidence interval [CI]: 0.3-0.7%), 1.5% (95% CI: 1.2-1.8%), and 10.4% (95% CI: 9.6-11.2%) in those 40 years of age and older. The prevalence of all three conditions increased with age (P < 0.001). Females had much higher rates of PACS, PAC, and PACG (P < 0.05); 21 persons with PACG (65%) were blind in at least one eye: 13 were due to glaucoma and the other 8 likely had other causes.
  
  
  CONCLUSIONS
  The prevalence of PACS, PAC, and PACG in this rural population is similar to what was previously reported in urban Chinese residents. Two thirds of those with PACG were blind in at least one eye. Strategies to detect and treat this preventable disease in rural China are needed.
authors: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology and Visual Science Key Lab, Beijing, China.
authors: Yuanbo
authors: Y
authors: Liang
authors: David S
authors: DS
authors: Friedman
authors: Qiang
authors: Q
authors: Zhou
authors: Xiao Hui
authors: XH
authors: Yang
authors: Lan Ping
authors: LP
authors: Sun
authors: Lixia
authors: L
authors: Guo
authors: Dolly S
authors: DS
authors: Chang
authors: Liying
authors: L
authors: Lian
authors: Ning Li
authors: NL
authors: Wang
mesh_terms: D000328:Adult; D017677:Age Distribution; D000368:Aged; D000867:Anterior Chamber / Q000473:pathology; D044466:Asian People / Q000706:statistics & numerical data*; D001766:Blindness / Q000208:ethnology / Q000473:pathology; D002681:China / Q000453:epidemiology; D005260:Female; D015812:Glaucoma, Angle-Closure / Q000208:ethnology* / Q000473:pathology*; D006068:Gonioscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D009898:Optic Disk / Q000473:pathology; D015995:Prevalence; D012424:Rural Population / Q000706:statistics & numerical data*; D017678:Sex Distribution