title: Intraocular pressure, central corneal thickness, and glaucoma in chinese adults: the liwan eye study.
abstract: OBJECTIVE
  To describe the distribution of central corneal thickness (CCT), intraocular pressure (IOP), and their determinants and association with glaucoma in Chinese adults.
  
  
  METHODS
  Population-based cross-sectional study.
  
  
  METHODS
  Chinese adults aged 50 years and older were identified using cluster random sampling in Liwan District, Guangzhou. CCT (both optical [OCCT] and ultrasound [UCCT]), intraocular pressure (by Tonopen, IOP), refractive error (by autorefractor, RE), radius of corneal curvature (RCC), axial length (AL), and body mass index (BMI) were measured, and history of hypertension and diabetes (DM) was collected by questionnaire. Right eye data were analyzed.
  
  
  RESULTS
  The mean values of OCCT, UCCT, and IOP were 512 ± 29.0 μm, 542 ± 31.4 μm, and 15.2 ± 3.1 mm Hg, respectively. In multiple regression models, CCT declined with age (P < .001) and increased with greater RCC (P < .001) and DM (P = .037). IOP was positively associated with greater CCT (P < .001), BMI (P < .001), and hypertension (P < .001). All 25 persons with open-angle glaucoma had IOP <21 mm Hg. CCT did not differ significantly between persons with and without open- or closed-angle glaucoma. Among 65 persons with ocular hypertension (IOP >97.5th percentile), CCT (555 ± 29 μm) was significantly (P = .01) higher than for normal persons.
  
  
  CONCLUSIONS
  The distributions of CCT and IOP in this study are similar to that for other Chinese populations, though IOP was lower than for European populations, possibly due to lower BMI and blood pressure. Glaucoma with IOP <21 mm Hg is common in this population. We found no association between glaucoma and CCT, though power (0.3) for this analysis was low.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Dandan
authors.initials: D
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Wenyong
authors.initials: W
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yuetao
authors.initials: Y
authors.lastname: Li
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Yingfeng
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: National Biomedical Research Centre for Ophthalmology, Institute of Ophthalmology, University College London and Moorfields Eye Hospital, London, United Kingdom.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Foster
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Nathan
authors.initials: N
authors.lastname: Congdon
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. Electronic address: mingguang_he@yahoo.com.
authors.forename: Mingguang
authors.initials: M
authors.lastname: He
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People / Q000208:ethnology*; D058452:Axial Length, Eye; D015992:Body Mass Index; D002681:China / Q000453:epidemiology; D003315:Cornea / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D005901:Glaucoma / Q000453:epidemiology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009798:Ocular Hypertension / Q000453:epidemiology; D011795:Surveys and Questionnaires; D041623:Tomography, Optical Coherence; D014065:Tonometry, Ocular; D014505:Urban Population / Q000706:statistics & numerical data