title: Pseudoexfoliation: normative data and associations: the Beijing eye study 2011.
abstract: OBJECTIVE
  To assess the prevalence of pseudoexfoliation syndrome (PEX) and its associations in a population-based setting.
  
  
  METHODS
  Population-based, cross-sectional cohort study.
  
  
  METHODS
  Of 4403 eligible subjects with an age of ≥ 50 years, 3468 individuals (78.8%) participated in the Beijing Eye Study 2011 (mean age, 64.6 ± 9.8 years; range, 50-93 years).
  
  
  METHODS
  All study participants underwent a detailed ophthalmologic examination. After medical pupil dilation, PEX was assessed by an experienced ophthalmologist using slit-lamp-based biomicroscopy.
  
  
  METHODS
  Prevalence and associations of PEX.
  
  
  RESULTS
  Slit-lamp examination results were available for 3022 study participants (87.1%). Definite pseudoexfoliation was observed in 72 of the 3022 subjects, with a prevalence of 2.38% (95% confidence interval [CI], 1.84-2.93). Suspected PEX was detected in 104 of the subjects (3.44%; 95% CI, 2.8-4.1). The overall prevalence of PEX (definite and suspected) was 176 of 3022 or 5.82% (95% CI, 4.99-6.66). In 80 subjects (45.5%), PEX was detected in both eyes, whereas it was detected only in the right eye in 42 subjects (23.9%) and only in the left eye in 54 (30.7%). The prevalence of PEX increased from 1.1% in among those 50 to 54 years old, to 3.5%, 5.7%, and 11.8% among those 60 to 64 years, 70 to 74 years, and ≥ 80 years, respectively. In multivariate analysis, presence of PEX was significantly associated with older age (P<0.001; odds ratio [OR], 1.08; 95% CI, 1.04-1.10), shorter axial length (P = 0.03; OR, 0.82; 95% CI, 0.68,0.98), and shallower anterior chamber (P = 0.03; OR, 0.59; 95% CI, 0.36-0.95). We found that PEX was not associated (all P>0.05) with sex, diabetes mellitus, blood pressure, psychological depression, smoking, dyslipidemia, body mass index, central corneal thickness, corneal diameter, optic nerve head measurements, choroidal thickness, retinal vessel diameters, early age-related macular degeneration, or retinal vein occlusion.
  
  
  CONCLUSIONS
  In a North Chinese population aged ≥ 50 years, the prevalence of definite PEX was 2.38% (95% CI, 1.84-2.93), suspect PEX was 3.4% (95% CI, 2.8-4.1) and overall PEX was 5.82% (95% CI, 4.99-6.66). We found PEX to be associated with older age, shorter axial length, and shallower anterior chamber. The relationship between PEX and glaucomatous optic neuropathy remained inconclusive among our population.
  
  
  BACKGROUND
  The authors have no proprietary or commercial interest in any materials discussed in this article.
authors.affiliation: Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital University of Medical Science, Beijing, China.
authors.forename: Qi Sheng
authors.initials: QS
authors.lastname: You
authors.forename: Liang
authors.initials: L
authors.lastname: Xu
authors.forename: Ya Xing
authors.initials: YX
authors.lastname: Wang
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.forename: Ke
authors.initials: K
authors.lastname: Ma
authors.forename: Jian Jun
authors.initials: JJ
authors.lastname: Li
authors.forename: Li
authors.initials: L
authors.lastname: Zhang
authors.forename: Jost B
authors.initials: JB
authors.lastname: Jonas
mesh_terms: D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000453:epidemiology; D003430:Cross-Sectional Studies; D017889:Exfoliation Syndrome / Q000175:diagnosis / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D008853:Microscopy; D008875:Middle Aged; D016011:Normal Distribution; D015995:Prevalence; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data; D017678:Sex Distribution; D014505:Urban Population / Q000706:statistics & numerical data