title: The relationship of intraocular pressure with age, systolic blood pressure, and central corneal thickness in an asian population.
abstract: OBJECTIVE
  To describe the distribution of intraocular pressure (IOP) and its cross-sectional relationship to age, systolic blood pressure (sBP), and central corneal thickness (CCT) in an Asian population.
  
  
  METHODS
  This was a population-based, cross-sectional study of 3280 Malay subjects (78.7% response) aged 40 to 80 years residing in Singapore. The participants had a standardized interview, examination, and ocular imaging at a centralized study clinic. IOP was measured with Goldmann applanation tonometry (GAT) before pupil dilation, CCT measurements were obtained with an ultrasound pachymeters, and sBP was taken with participants seated after 5 minutes of rest with an automatic blood pressure monitor.
  
  
  RESULTS
  IOP increased with age to the sixth decade, after which a decrease in IOP was seen with further increase in age, resulting in an inverted U pattern. sBP increased linearly with age whereas CCT decreased linearly with age. In regression models, age, CCT, and sBP were all significant determinants of IOP (P < 0.001 for all three). In younger persons aged 40 to 59 years, both CCT and sBP were positively associated with IOP (P < 0.001 for both), but in older persons of 60 to 80 years, only age and sBP had a positive association with of IOP (P = 0.001 for age, P < 0.001 for sBP).
  
  
  CONCLUSIONS
  Age, CCT and sBP are significant determinants of IOP in persons aged 40 to 80 years, with CCT being a more important determinant in younger persons. The opposing effects of age-specific changes in sBP and CCT interact to lead to a relatively flat profile of IOP with age, possibly with a subtle inverted U-shaped relationship.
authors.affiliation: Singapore Eye Research Institute and Singapore National Eye Centre, Singapore; the.
authors.forename: Tina T
authors.initials: TT
authors.lastname: Wong
authors.forename: Tien Y
authors.initials: TY
authors.lastname: Wong
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Foster
authors.forename: Jonathan G
authors.initials: JG
authors.lastname: Crowston
authors.forename: Chee-Weng
authors.initials: CW
authors.lastname: Fong
authors.forename: Tin
authors.initials: T
authors.lastname: Aung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000502:physiology*; D044466:Asian People / Q000208:ethnology*; D001794:Blood Pressure / Q000502:physiology*; D001795:Blood Pressure Determination; D001824:Body Constitution; D003315:Cornea / Q000033:anatomy & histology*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D012846:Singapore / Q000453:epidemiology; D014065:Tonometry, Ocular