title: Comparison of horizontal corneal diameter measurements using Galilei, EyeSys and Orbscan II systems.
abstract: BACKGROUND
  White-to-white corneal measurement is used frequently in cataract and refractive surgery as well as in diagnosing various corneal diseases and monitoring congenital glaucoma. In this article, we determine agreement in horizontal corneal diameter measurements in normal eyes among the Galilei V4.01, the EyeSys and the Orbscan IIz.
  
  
  METHODS
  In this prospective study, 37 consecutive volunteers were enrolled. All 74 eyes were measured with all three devices. Galilei, EyeSys and Orbscan II measurements were compared with one another. In addition, the data from the right and left eyes were compared for each device.
  
  
  RESULTS
  The mean horizontal corneal diameter measurements with the Galilei, the EyeSys and the Orbscan II were 12.01 +/- 0.61 mm, 12.09 +/- 0.87 mm and 11.67 +/- 0.29 mm, respectively. The difference between the Galilei and EyeSys systems was not statistically significant (p = 0.76), however, the Orbscan II showed smaller measurements (p < 0.001). The best 95% limits of agreement between devices were for the Galilei and the Orbscan II (-0.72, 1.48; r = 0.4, p < 0.01). The best 95% limits of agreement between two eyes for each device were found with the Orbscan II (-0.15, 0.17; r = 0.996, p < 0.01). There was no correlation between measurements of right and left eyes for the Galilei or the EyeSys (r = 0.274, p = 0.176 and r = 0.31, p = 0.065, respectively).
  
  
  CONCLUSIONS
  These results suggest that measurements made with the Orbscan II are smaller than those obtained with the EyeSys Corneal Analysis system and the Galilei. Among the three devices, the Galilei and the Orbscan II showed the best agreement, however, it is inadvisable to use the three devices interchangeably in every clinical situation.
authors.affiliation: Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran. saloutir@hotmail.com
authors.forename: Ramin
authors.initials: R
authors.lastname: Salouti
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Nowroozzadeh
authors.forename: Mohammad
authors.initials: M
authors.lastname: Zamani
authors.forename: Maryam
authors.initials: M
authors.lastname: Ghoreyshi
authors.forename: Rosa
authors.initials: R
authors.lastname: Salouti
mesh_terms: D000328:Adult; D003315:Cornea / Q000473:pathology; D003316:Corneal Diseases / Q000473:pathology; D019781:Corneal Topography / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D011446:Prospective Studies