title: Repeatability and reproducibility of Galilei measurements in normal keratoconic and postrefractive corneas.
abstract: OBJECTIVE
  To assess the repeatability and reproducibility of the anterior segment measurements performed with a dual Scheimpflug analyzer (Galilei) in normal, keratoconic and post-refractive surgery corneas.
  
  
  METHODS
  To evaluate the repeatability, two additional measurements were performed by the first examiner. To assess reproducibility, this was later followed by a single reading by the second examiner. The following parameters were recorded and evaluated in this study; central corneal thickness (CCT), thinnest corneal thickness (TCT), mean total corneal power (TCP) in central (0-4mm), mean posterior corneal power (PCP) in central (0.5-2mm), anterior and posterior elevation (best fit sphere [BFS]) in central 8mm anterior and posterior eccentricity (ɛ(2)) in central 8mm. Repeatability and reproducibility for each corneal parameter was assessed using the Bland-Altman analysis.
  
  
  RESULTS
  Each of the three groups was consisted of 20 subjects (totally 60 patients, 30 men and 30 women). The 95% LoA for repeatability was very small, indicating small discrepancies between measurements related to CCT. Acceptable repeatability was also achieved for the other parameters in each group. However, the 95% LoA for value TCP was larger in keratoconic eyes. The 95% LoA for reproducibility was also very small, and acceptable for all measured parameters in each group. In addition, the 95% LoA was larger for the measurement of CCT and TCT for postrefractive corneas.
  
  
  CONCLUSIONS
  The anterior segment measurements provided by Galilei showed good repeatability and reproducibility for normal, keratoconic and postrefractive corneas.
authors.affiliation: Turgut Özal University, Medical School, Department of Ophthalmology, Ankara, Turkey. Electronic address: guleremre83@hotmail.com.
authors.forename: Emre
authors.initials: E
authors.lastname: Güler
authors.affiliation: Pamukkale University, Medical School, Department of Ophthalmology, Denizli, Turkey.
authors.forename: Ramazan
authors.initials: R
authors.lastname: Yağci
authors.affiliation: Yıldırım Beyazıt University, Department of Biostatistics, Ankara, Turkey.
authors.forename: Mesut
authors.initials: M
authors.lastname: Akyol
authors.affiliation: Adıyaman University Training and Research Hospital, Department of Ophthalmology, Adıyaman, Turkey.
authors.forename: Zeynel
authors.initials: Z
authors.lastname: Arslanyılmaz
authors.affiliation: Abdurrahman Yurtaslan Oncology Training and Research Hospital, Department of Ophthalmology, Ankara, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Balci
authors.affiliation: Gazi University, Medical School, Department of Ophthalmology, Ankara, Turkey.
authors.forename: Ibrahim F
authors.initials: IF
authors.lastname: Hepşen
mesh_terms: D000328:Adult; D003315:Cornea / Q000473:pathology*; D063171:Corneal Pachymetry / Q000295:instrumentation*; D019781:Corneal Topography / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007640:Keratoconus / Q000473:pathology*; D008297:Male; D009216:Myopia / Q000473:pathology* / Q000601:surgery; D011446:Prospective Studies; D054140:Refractive Surgical Procedures; D015203:Reproducibility of Results; D055815:Young Adult
keywords: Galilei; Keratoconus; Repeatability; Reproducibility