title: A longitudinal study of age-related changes in intraocular pressure: the Kangbuk Samsung Health Study.
abstract: OBJECTIVE
  To examine the longitudinal association between age and intraocular pressure (IOP) in a large sample of Korean men and women.
  
  
  METHODS
  We conducted a prospective cohort study of 274,064 young and middle-aged Korean adults with normal fundoscopic findings, following them from January 1, 2002, to February 28, 2010. Health exams were scheduled annually or biennially. At each visit, IOP was measured in both eyes using automated noncontact tonometers. The longitudinal change in IOP with age was evaluated using three-level mixed models for longitudinal paired-eye data, accounting for correlations between paired eyes and repeated measurements over time.
  
  
  RESULTS
  In fully adjusted models, the average longitudinal change in IOP per 1-year increase in age was -0.065 mm Hg (95% confidence interval [CI] -0.068 to -0.063), with marked sex differences (P < 0.001). In men, the average annual IOP change was -0.093 mm Hg (95% CI -0.096 to -0.091) throughout follow-up. In women, the average annual IOP change was -0.006 mm Hg (95% CI -0.010 to -0.003), with a relatively flat association in the age range of 30 to 59 years and more marked annual decreases at younger and older ages.
  
  
  CONCLUSIONS
  Intraocular pressure was inversely associated with age in a large cohort of Korean adults attending health-screening visits. For men, this inverse association was observed throughout the entire age range, while for women it was evident only in younger (<30 years of age) and older (≥60 years of age) women, with no association in women aged 30 to 59. Further research is needed to better understand the underlying mechanisms and to reconsider cutoffs for defining high IOP by age and sex groups in Asian populations.
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States.
authors.forename: Di
authors.initials: D
authors.lastname: Zhao
authors.affiliation: Department of Epidemiology, Graduate School of Public Health, Seoul National University, Seoul, Korea.
authors.forename: Myung Hun
authors.initials: MH
authors.lastname: Kim
authors.affiliation: National Center for Epidemiology, Carlos III Institute of Health and Consortium for Biomedical Research in Epidemiology and Public Health (CIBERESP), Madrid, Spain.
authors.forename: Roberto
authors.initials: R
authors.lastname: Pastor-Barriuso
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea Department of Occupational and Environmental Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Yoosoo
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea Department of Occupational and Environmental Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Seungho
authors.initials: S
authors.lastname: Ryu
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States.
authors.forename: Yiyi
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States Department of Social and Preventive Medicine, Julius Centre University of Malaya, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Rampal
authors.affiliation: Department of Family Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Hocheol
authors.initials: H
authors.lastname: Shin
authors.affiliation: Department of Ophthalmology, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Joon Mo
authors.initials: JM
authors.lastname: Kim
authors.affiliation: The Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, Maryland, United States.
authors.forename: David S
authors.initials: DS
authors.lastname: Friedman
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States.
authors.forename: Eliseo
authors.initials: E
authors.lastname: Guallar
authors.affiliation: Department of Epidemiology and Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, United States Center for Cohort Studies, Total Healthcare Center, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, South Korea Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, South Korea Biostatistics and Clinical Epidemiology Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, South Korea.
authors.forename: Juhee
authors.initials: J
authors.lastname: Cho
mesh_terms: D000328:Adult; D017677:Age Distribution; D000375:Aging; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005902:Glaucoma, Open-Angle / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D009017:Morbidity / Q000639:trends; D009798:Ocular Hypertension / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology*; D011379:Prognosis; D011446:Prospective Studies; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D017678:Sex Distribution; D013997:Time Factors; D014065:Tonometry, Ocular
keywords: age; intraocular pressure