title: Five-Year Incidence and Predictors for Pterygium in a Rural Community in China: The Yunnan Minority Eye Study.
abstract: OBJECTIVE
  To determine the 5-year cumulative incidence of pterygium and its associated predictors in the Bai Chinese population in a rural community.
  
  
  METHODS
  This population-based study included 2133 subjects aged 50 years or older in 2010 and was repeated in 2015 with 1520 subjects (71.3%) participating in the follow-up examination. Participants with pterygium in either eye in 2010 were excluded from the analysis related to incidence. Anterior segment examination was performed without pupil dilation using a slit lamp, and pterygium was defined as a raised fleshy triangular fibrovascular tissue growth of the conjunctiva encroaching onto the clear cornea.
  
  
  RESULTS
  The 5-year cumulative incidence of pterygium was 6.8% [95% confidence interval (CI), 5.2-8.4] and was significantly higher in women compared with men (8.8% vs. 3.8%; P = 0.003). The age-specific incidence was 7.7%, 6.5%, and 5.6% in those aged 50-59, 60-69, 70 years, or older at the baseline, respectively. Outdoor occupation was the only predictor, which remained to be significantly associated with a higher incidence of pterygium in multivariate analysis (odds ratio = 2.52, 95% CI, 1.27-4.95). The predictive effect of outdoor occupation on incident pterygium was moderate with an area under the curve in the receiver operating characteristic analysis of 0.59 (95% CI, 0.53-0.66).
  
  
  CONCLUSIONS
  The incidence of pterygium in this rural cohort was higher compared to a previous report in Chinese in urban areas. The findings are important for health policy makers to project future burden of pterygium and make proper decisions on health resource allocation.
authors.affiliation: *Department of Ophthalmology, the First People's Hospital of Kunming City, Kunming, China; †Department of Ophthalmology, the First Affiliated Hospital of Kunming Medical University, Kunming, China; ‡Kunming Medical University, Kunming, China; §State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China; and ¶School of Public Health, Medical College of Soochow University, Suzhou, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Li
authors.forename: Hua
authors.initials: H
authors.lastname: Zhong
authors.forename: Ermiao
authors.initials: E
authors.lastname: Tian
authors.forename: Minbin
authors.initials: M
authors.lastname: Yu
authors.forename: Yuansheng
authors.initials: Y
authors.lastname: Yuan
authors.forename: Wenyan
authors.initials: W
authors.lastname: Yang
authors.forename: Tao
authors.initials: T
authors.lastname: Wei
authors.forename: Xueping
authors.initials: X
authors.lastname: Cha
authors.forename: Xun
authors.initials: X
authors.lastname: Li
authors.forename: Juanjuan
authors.initials: J
authors.lastname: Li
authors.forename: Xiaodan
authors.initials: X
authors.lastname: Su
authors.forename: Chen-Wei
authors.initials: CW
authors.lastname: Pan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000208:ethnology*; D002681:China / Q000453:epidemiology; D004781:Environmental Exposure / Q000706:statistics & numerical data; D005006:Ethnicity / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D008913:Minority Groups / Q000706:statistics & numerical data*; D009790:Occupations; D011625:Pterygium / Q000145:classification / Q000208:ethnology*; D012372:ROC Curve; D012424:Rural Population / Q000706:statistics & numerical data*; D013472:Sunlight