title: Central corneal thickness and intraocular pressure in a Mongolian population.
abstract: OBJECTIVE
  The purpose of the study was to quantify the variation of central corneal thickness (CCT) in an east Asian population and to examine its relationship to estimates of intraocular pressure (IOP) made with an applanation tonometer.
  
  
  METHODS
  The study design was a cross-sectional, population-based survey.
  
  
  METHODS
  One thousand two-hundred forty-two residents of Hövsgöl Province, Mongolia, 10 to 87 years of age participated.
  
  
  METHODS
  The CCT was measured using an optical pachymeter in all subjects. The IOP was measured using a, Goldmann-type applanation tonometer in subjects 40 years of age and older.
  
  
  RESULTS
  There was a highly significant decrease in CCT with age: 5 microns/decade in men and 6 microns/decade in women (both, P < 0.0001). A highly significant positive correlation was identified between IOP and CCT. Linear regression analysis suggests that between the ages of 40 and 80 years, an increase in CCT of 10 microns is associated with an increase in IOP measurements of 0.18 mmHg in right eyes (95% confidence interval, 0.12-0.25) and 0.24 mmHg in left eyes (95% confidence interval, 0.17-0.31). The authors calculate that interindividual differences in CCT may produce a difference in measured IOP of between 2.3 and 3.1 mmHg.
  
  
  CONCLUSIONS
  Variation in CCT is a significant source of variation in IOP measurements between individuals. The authors suggest that measurement of corneal thickness should be considered when assessing IOP as a risk factor for glaucoma in east Asians.
authors.affiliation: Department of Preventive Ophthalmology, Institute of Ophthalmology, London, England.
authors.forename: P J
authors.initials: PJ
authors.lastname: Foster
authors.forename: J
authors.initials: J
authors.lastname: Baasanhu
authors.forename: P H
authors.initials: PH
authors.lastname: Alsbirk
authors.forename: D
authors.initials: D
authors.lastname: Munkhbayar
authors.forename: D
authors.initials: D
authors.lastname: Uranchimeg
authors.forename: G J
authors.initials: GJ
authors.lastname: Johnson
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology; D002648:Child; D003315:Cornea / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D006306:Health Surveys; D006801:Humans; D007429:Intraocular Pressure; D008297:Male; D008875:Middle Aged; D008986:Mongolia; D017678:Sex Distribution; D014065:Tonometry, Ocular