title: Comparison between Two Scheimpflug Anterior Segment Analyzers.
abstract: OBJECTIVE
  To compare the anterior segment indices measured by two Scheimpflug camera machines; Galilei and Pentacam.
  
  
  METHODS
  In this observational case series, the anterior segment indices of myopic healthy subjects seeking for refractive surgery were measured by Pentacam and Galilei on the same day. Analyzed parameters were anterior and posterior best fit spheres (BFS), axial curvature, true corneal power, central corneal thickness (CCT), anterior chamber (AC) depth, AC volume, AC angle, and pupil diameter.
  
  
  RESULTS
  This study included 176 eyes of 88 participants. Mean radius of the anterior BFS was 7.79 ± 0.34 mm versus 7.75 ± 0.39 mm measured by Pentacam and Galilei, respectively (r= 0.877,P< 0.001). Corresponding values for the mean radius of posterior BFS were 6.42 ± 0.32 and 6.47 ± 0.38 mm, respectively (r= 0.879,P< 0.001). Anterior corneal mean power was 43.8 ± 1.9 diopters (D) with Pentacam and 43.8 ± 2.4 D with Galilei (r= 0.905,P < 0.001). Posterior corneal mean power was measured - 6.3 ± 0.3 and - 6.3 ± 0.4 D using Pentacam and Galilei, respectively (r= 0.873,P< 0.001). True corneal power was 43.9 ± 1.9 D with Pentacam and 43.5 ± 2.3 D with Galilei (r= 0.909,P< 0.001). CCT was 537 ± 44 and 553 ± 51 μm measured by Pentacam and Galilei, respectively (r= 0.796,P< 0.001). AC depth measurements using Pentacam and Galilei were 3.29 ± 0.4 and 3.3 ± 0.38 mm (P< 0.001), respectively; AC volume was 207 ± 50 and 129 ± 39 mm3≥ (P= 0.004), and AC angle was 39.7 ± 9.2 and 54.2 ± 5.2 degrees (P= 0.051), respectively. Average pupil diameter was measured 3.91 ± 1.77 mm by Pentacam and 3.34 ± 0.89 mm by Galilei (P= 0.018).
  
  
  CONCLUSIONS
  There was a significant correlation between the Pentacam and Galilei in all measured parameters except AC angle, AC volume, and average pupil diameter.
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Alireza
authors.initials: A
authors.lastname: Baradaran-Rafii
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Tahmineh
authors.initials: T
authors.lastname: Motevasseli
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Forouzan
authors.initials: F
authors.lastname: Yazdizadeh
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Farid
authors.initials: F
authors.lastname: Karimian
authors.affiliation: Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Sahba
authors.initials: S
authors.lastname: Fekri
authors.affiliation: Department of Mechanical Engineering, Amirkabir University of Technology, Tehran, Iran.
authors.forename: Amir
authors.initials: A
authors.lastname: Baradaran-Rafii
keywords: Corneal Imaging; Galilei; Pentacam; Scheimpflug Analyzer