title: Intraocular pressure and its relationship to ocular and systemic factors in a healthy Chinese rural population: the Handan Eye Study.
abstract: OBJECTIVE
  To describe the distribution of and factors related to intraocular pressure (IOP) in a healthy adult rural Chinese population in northern China.
  
  
  METHODS
  The Handan Eye Study is a cross-sectional, population-based study of eye diseases among 6,830 (90.4% response rate) rural Chinese persons aged 30+ years. Participants underwent an interviewer-administered questionnaire and a complete ocular examination, including standardized measurement of IOP with Perkins applanation tonometry.
  
  
  RESULTS
  After excluding persons with glaucoma, or those with diseases that have a marked effect on IOP or that preclude accurate IOP measurement, 6,101 persons were included in the current analysis. Mean IOP (mean ± standard deviation) of the study population was 15.0 ± 2.8 mmHg. Men had lower IOP than women (14.6 ± 2.8 mmHg versus 15.4 ± 2.7 mmHg, t = -8.37, P < 0.001). In the multivariate analysis younger age, female sex, presence of diabetes mellitus, higher blood pressure, higher body mass index, thicker central cornea and higher myopia were associated with higher IOP.
  
  
  CONCLUSIONS
  Mean IOP among persons living in rural northern China was similar to that recently reported in southern China. IOP appeared to be lower with increasing age in Chinese subjects, which contrasts with results in white populations.
authors.affiliation: Beijing Chaoyang Hospital, Capital Medical University, Beijing, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhou
authors.forename: Yuan Bo
authors.initials: YB
authors.lastname: Liang
authors.forename: Tien Yin
authors.initials: TY
authors.lastname: Wong
authors.forename: Xiao Hui
authors.initials: XH
authors.lastname: Yang
authors.forename: Liying
authors.initials: L
authors.lastname: Lian
authors.forename: Dan
authors.initials: D
authors.lastname: Zhu
authors.forename: Lan Ping
authors.initials: LP
authors.lastname: Sun
authors.forename: Ning Li
authors.initials: NL
authors.lastname: Wang
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001794:Blood Pressure / Q000502:physiology; D015992:Body Mass Index; D002681:China / Q000453:epidemiology; D003315:Cornea / Q000503:physiopathology; D003430:Cross-Sectional Studies; D048909:Diabetes Complications / Q000453:epidemiology / Q000503:physiopathology; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology / Q000503:physiopathology; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology; D012307:Risk Factors; D012424:Rural Population / Q000706:statistics & numerical data*; D011795:Surveys and Questionnaires; D014065:Tonometry, Ocular