title: Twenty-four-hour intraocular pressure pattern associated with early glaucomatous changes.
abstract: OBJECTIVE
  To characterize the 24-hour pattern of intraocular pressure (IOP) in untreated patients with newly diagnosed early glaucomatous changes.
  
  
  METHODS
  Measurements of IOP, blood pressure, and heart rate were taken every 2 hours during a 24-hour period from a group of 24 untreated patients (ages 40-78 years) with newly diagnosed abnormal optic discs and/or abnormal visual fields. In the 16-hour diurnal awake period, IOP was measured sitting and supine, and blood pressure and heart rate were measured supine. In the 8-hour nocturnal sleep period, all measurements were taken in the supine position. Mean diurnal and nocturnal IOP, blood pressure, and heart rate in the glaucoma group were compared with data obtained from an age-matched control group of 24 individuals with healthy eyes.
  
  
  RESULTS
  Mean diurnal IOP, either sitting or supine, was significantly higher in the glaucoma group than in the control group. For both subject groups, nocturnal supine IOP was higher than diurnal sitting IOP. However, this diurnal-to-nocturnal increase in IOP was significantly smaller in the glaucoma group. When compared with the diurnal supine IOP, the nocturnal supine IOP was lower in the glaucoma group but higher in the control group. Around normal awakening time, the supine IOP increased in the glaucoma group and did not change in the control group. There was a diurnal-to-nocturnal decrease in mean blood pressure only in the glaucoma group.
  
  
  CONCLUSIONS
  Compared with healthy eyes, the diurnal IOP is higher, the diurnal-to-nocturnal change of habitual IOP is less, and the posture-independent IOP pattern around normal awakening time is different in eyes with early glaucomatous changes.
authors.affiliation: Hamilton Glaucoma Center and Department of Ophthalmology, University of California, San Diego, La Jolla, California 92093, USA.
authors.forename: John H K
authors.initials: JH
authors.lastname: Liu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Zhang
authors.forename: Daniel F
authors.initials: DF
authors.lastname: Kripke
authors.forename: Robert N
authors.initials: RN
authors.lastname: Weinreb
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D002940:Circadian Rhythm / Q000502:physiology*; D005260:Female; D005901:Glaucoma / Q000503:physiopathology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011187:Posture