title: Comparison of three intraocular pressure measurement methods including biomechanical properties of the cornea.
abstract: OBJECTIVE
  The aim of this study was to show the usefulness of three methods for measuring IOP: Goldmann applanation tonometry, rebound tonometry, and Ultra-High-Speed Scheimpflug technology.
  
  
  METHODS
  The examined group consisted of 96 patients (192 eyes), including 63 women and 33 men with a mean age of 59.3 ± 19.9 years. Together, 152 healthy eyes and 40 eyes with different pathologies were examined. Intraocular pressure was measured using the Goldmann applanation tonometer (GAT), the Icare Pro rebound tonometer (RT), and Ultra-High-Speed Scheimpflug technology (UHS ST; Corvis ST with pachymetry). Additionally, corneal pachymetry was conducted with a Scheimpflug camera (Pentacam) and an Ultrasound Pachymeter (A-scan Plus) as a comparison for Corvis ST pachymetry.
  
  
  RESULTS
  The mean IOPs were 15.6 ± 3.75 mm Hg, 15.6 ± 3.5 mm Hg, and 16.1 ± 4.0 mm Hg when measured with the GAT, the RT, and the UHS ST, respectively. The mean central corneal thickness (CCT) was 543.7 ± 52.7 μm, 547.9 ± 54.0 μm, and 556.25 ± 38.8 μm as measured with the UHS ST, the Pentacam, and the Ultrasound Pachymeter, respectively. In comparison between devices, there was a significant difference between IOP values measured with the GAT and the RT versus the UHS ST (P < 0.001), and there was no significant difference between GAT and RT (P = 0.5). No significant differences were observed in CCT measured with the UHS ST, Pentacam, and Ultrasound Pachymeter.
  
  
  CONCLUSIONS
  We showed that the RT Icare Pro ensures IOP measurements that are more comparable with the measurements obtained with the GAT than the measurements that are provided by UHS ST.
authors.affiliation: Department of Ophthalmology, Medical University of Silesia, Railway Hospital, Katowice, Poland.
authors.forename: Adrian
authors.initials: A
authors.lastname: Smedowski
authors.forename: Beata
authors.initials: B
authors.lastname: Weglarz
authors.forename: Dorota
authors.initials: D
authors.lastname: Tarnawska
authors.forename: Kai
authors.initials: K
authors.lastname: Kaarniranta
authors.forename: Edward
authors.initials: E
authors.lastname: Wylegala
mesh_terms: D003315:Cornea / Q000503:physiopathology*; D015715:Corneal Edema / Q000503:physiopathology; D063171:Corneal Pachymetry; D004548:Elasticity / Q000502:physiology*; D005260:Female; D005901:Glaucoma / Q000503:physiopathology; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D007640:Keratoconus / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D014065:Tonometry, Ocular / Q000379:methods*
keywords: corneal biomechanics; intraocular pressure; tonometry