title: Diurnal intraocular pressure patterns are not repeatable in the short term in healthy individuals.
abstract: OBJECTIVE
  To evaluate the short-term repeatability of diurnal intraocular pressure (IOP) patterns in eyes of subjects without glaucoma.
  
  
  METHODS
  Observational cohort study.
  
  
  METHODS
  Forty healthy subjects without glaucoma.
  
  
  METHODS
  Subjects underwent 12-hour diurnal IOP assessment sessions from 8:00 am to 8:00 pm on 2 visits 1 week apart. Intraocular pressure was assessed by Goldmann applanation tonometry. An analysis was performed to determine the agreement of individual diurnal IOP patterns from the first visit to the second visit. The intraclass correlation coefficient (ICC) was used to analyze both agreement of IOP values at each time point between visits and IOP change over periods between time points between visits.
  
  
  METHODS
  Diurnal IOP patterns.
  
  
  RESULTS
  Between-visit agreement of IOP values at each time point generally was fair to good, with ICCs ranging from 0.37 to 0.62 in right eyes and from 0.35 to 0.71 in left eyes. Between-visit agreement of IOP change over time between time points was uniformly poor and often below that expected by chance alone, with ICCs ranging from -0.25 to 0.15 in right eyes and from -0.40 to 0.22 in left eyes.
  
  
  CONCLUSIONS
  Eyes of healthy individuals do not manifest a sustained and reproducible diurnal IOP pattern when measured by Goldmann tonometry. A single-day assessment of IOP incompletely characterizes the diurnal IOP pattern.
authors.affiliation: West Virginia University Eye Institute, Morgantown, West Virginia, USA. realinia@wvuh.com
authors.forename: Tony
authors.initials: T
authors.lastname: Realini
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Wisniewski
mesh_terms: D000368:Aged; D002940:Circadian Rhythm / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D011446:Prospective Studies; D015203:Reproducibility of Results; D014065:Tonometry, Ocular; D014794:Visual Fields