title: The prevalence and risk factors for pterygium in South Korea: the Korea National Health and Nutrition Examination Survey (KNHANES) 2009-2010.
abstract: OBJECTIVE
  To determine the prevalence and risk factors for pterygium in the adult Korean population of South Korea.
  
  
  METHODS
  Data were analyzed from 9,193 participants who were 40 years of age or older from the Korea National Health and Nutrition Examination Survey (KNHANES), conducted from 2009 to 2010. Standardized slit-lamp examinations were performed by study ophthalmologists to examine the anterior segment for evidence of pterygium. Pterygium was graded clinically as T1 (atrophic), T2 (intermediate), or T3 (opaque). Every participant underwent ocular and systemic examinations, as well as interviewer-administered questionnaires. Any evidence of pterygium and observed association between the risk factors were recorded.
  
  
  RESULTS
  The mean age of the subjects was 55.7 (±0.2) years. Of the 9,193 eligible subjects, 935 had pterygium in at least one eye. In a multivariate logistic regression analysis adjusted for age and sex, pterygium was significantly associated with rural vs. urban residence (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.4 to 2.0), lower level of education (OR, 4.5; 95% CI, 3.1 to 6.6), low income (OR, 1.3; 95% CI, 1.0 to 1.8), smoking (OR, 0.7; 95% CI, 0.5 to 1.0), and more hours of sun exposure (OR, 1.5; 95% CI, 1.2 to 1.8). After adjusting for all variables, the prevalence of pterygium was significantly associated with age, sex, residence, education level, and smoking.
  
  
  CONCLUSIONS
  This is a nationwide epidemiologic study in South Korea to assess the prevalence of and risk factors for pterygium. The overall prevalence of pterygium was 8.8% among Koreans aged 40 years or older. Older age, male gender, rural residence, lower level of education, and non-smoking were associated with the development of pterygium.
authors.affiliation: Department of Nursing, Kyung-In Women's University, Inchon, Korea.
authors.forename: Eun-Young
authors.initials: EY
authors.lastname: Pyo
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Gui Hyeong
authors.initials: GH
authors.lastname: Mun
authors.affiliation: Department of Ophthalmology, Chonnam National University Medical School, Gwangju, Korea.
authors.forename: Kyung Chul
authors.initials: KC
authors.lastname: Yoon
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D004522:Educational Status; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009749:Nutrition Surveys; D016017:Odds Ratio; D015995:Prevalence; D011625:Pterygium / Q000453:epidemiology / Q000209:etiology*; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012424:Rural Population; D012737:Sex Factors; D012907:Smoking
keywords: National Health and Nutrition Examination Survey; Prevalence; Pterygium; Republic of Korea; Risk factors