title: Prevalence of age-related macular degeneration in a rural Chinese population: the Handan Eye Study.
abstract: OBJECTIVE
  To describe the prevalence of age-related degeneration (AMD) in a rural Chinese population and to assess its associations with age, gender, and smoking.
  
  
  METHODS
  Population-based cross-sectional.
  
  
  METHODS
  Persons aged 30+ years, recruited between October 2006 and October 2007, from Yongnian County, Handan, Hebei Province, China.
  
  
  METHODS
  All participants underwent a standardized interview and comprehensive eye examinations, including digital retinal photography of both eyes. Trained graders assessed the presence and severity of AMD lesions following the modified Wisconsin Age-related Maculopathy Grading System (WARMGS) used in the Blue Mountains Eye Study (BMES). Direct age standardization to the world population (year 2000) was performed to compare the prevalence across different populations.
  
  
  METHODS
  AMD and WARMGS.
  
  
  RESULTS
  Of 6830 participates, fundus photographs were gradable for 6581 persons (96.4%), including 4049 aged 50+ years. Early and late AMD prevalence rates were 3.0% and 0.1%, respectively, among participants. The age-standardized prevalence rates among participants aged 50+ years were 4.7% and 0.2%, respectively. After controlling for age, men had a higher prevalence of early (3.9% vs. 2.3%, odds ratio [OR] 1.7; 95% confidence interval [CI], 1.3-2.2) and late AMD (0.1% vs. 0.03%; OR 3.5; CI, 0.4-33.4) compared with women. Older age (sex-adjusted OR 1.7; CI, 1.3-2.2 per decade of age) and current smoking (age-sex-adjusted OR 1.4; CI, 1.0-2.1) were significantly associated with early AMD prevalence. The proportion of current smokers was substantially higher in men (58.7%) than in women (0.3%). The attributable risk of early AMD from smoking among Chinese men was 24.2%. After controlling for current smoking, the excess prevalence of early AMD in men compared with women reduced by 50% (OR 1.4; 95% CI, 0.9-2.0).
  
  
  CONCLUSIONS
  The prevalence of early AMD in this rural Chinese sample was similar to white persons in the BMES and Asian Malays in the Singapore Malay Eye Study. Late AMD prevalence, however, was lower. Higher prevalence rates for early and late AMD in men compared with women were largely attributed to substantially higher proportions of smokers in rural Chinese men than in women.
authors: Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
authors: Ke
authors: K
authors: Yang
authors: Yuan Bo
authors: YB
authors: Liang
authors: Li Qin
authors: LQ
authors: Gao
authors: Yi
authors: Y
authors: Peng
authors: Ran
authors: R
authors: Shen
authors: Xin Rong
authors: XR
authors: Duan
authors: David S
authors: DS
authors: Friedman
authors: Lan Ping
authors: LP
authors: Sun
authors: Paul
authors: P
authors: Mitchell
authors: Ning Li
authors: NL
authors: Wang
authors: Tien Yin
authors: TY
authors: Wong
authors: Jie Jin
authors: JJ
authors: Wang
mesh_terms: D000328:Adult; D017677:Age Distribution; D044466:Asian People / Q000706:statistics & numerical data*; D002681:China / Q000453:epidemiology; D005260:Female; D005654:Fundus Oculi; D006801:Humans; D008268:Macular Degeneration / Q000453:epidemiology* / Q000209:etiology / Q000473:pathology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012424:Rural Population / Q000706:statistics & numerical data*; D012720:Severity of Illness Index; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology