title: Measurement of the difference in intraocular pressure between the sitting and lying body positions in healthy subjects: direct comparison of the Icare Pro with the Goldmann applanation tonometer, Pneumatonometer and Tonopen XL.
abstract: BACKGROUND
  Change in intraocular pressure is known to occur with body posture. Previously, markedly different estimations of this change were reported. The Icare Pro (Icare; Tiolat Oy, Helsinki, Finland) is designed to measure intraocular pressure with the subject supine. We compared the measurement of postural change in intraocular pressure obtained with this and 3 other tonometers: Goldmann applanation tonometer (CSO, Firenze, Italy), Pneumatonometer (Model 30, Reichert, Depew, NY, USA) and the Tonopen XL (Reichert).
  
  
  METHODS
  Prospective comparative study.
  
  
  METHODS
  Twenty-one healthy subjects.
  
  
  METHODS
  Intraocular pressure was measured in random order with four tonometers, first sitting then after 10 min of lying.
  
  
  METHODS
  Average postural intraocular pressure change (mmHg) and the 95% limits of agreement for measuring postural intraocular pressure change between tonometers.
  
  
  RESULTS
  Average postural intraocular pressure change (lying minus sitting, mmHg) was measured highest with the Goldmann applanation tonometer (4.1 ± 2.6) and Pneumatonometer (3.9 ± 2.1), significantly lower with the Tonopen (0.9 ± 1.7) and was negative with the Icare (-0.9 ± 3.3). The 95% limits of agreement for measuring postural intraocular pressure change between Goldmann applanation tonometer and Icare, Pneumatonometer and Tonopen were -3.2-13.3, -6.4-6.9 and -2.8-9.4 mmHg, respectively.
  
  
  CONCLUSIONS
  Postural change in intraocular pressure was measured similarly, on average, with Goldmann applanation tonometer and Pneumatonometer, and much lower with Tonopen and Icare Pro. There was poor interdevice agreement in measuring this parameter. We observed high intersubject variability, suggesting the clinical importance of this measurement in the diagnosis and management of glaucoma.
authors.affiliation: Department of Ophthalmology, Assaf Harofeh Medical Center, Zerifin, Israel.
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Barkana
authors.forename: Shay
authors.initials: S
authors.lastname: Gutfreund
mesh_terms: D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010865:Pilot Projects; D011187:Posture / Q000502:physiology*; D011446:Prospective Studies; D015203:Reproducibility of Results; D014065:Tonometry, Ocular / Q000295:instrumentation*; D055815:Young Adult
keywords: Goldmann; Icare Pro; Pneumatonometer; supine