title: Repeatability and intrasession reproducibility obtained by the Sirius anterior segment analysis system.
abstract: OBJECTIVE
  To analyze repeatability and intrasession reproducibility of anterior segment measurements using the newly developed Sirius Scheimpflug system.
  
  
  METHODS
  Three consecutive measurements on 100 eyes of 50 healthy subjects were performed on the same session by the same technician using the Sirius device at the Assuta Optic Laser Center, Tel-Aviv, Israel. For each eye, the following parameters were measured: anterior chamber angle (ACA), anterior chamber volume (ACV), and anterior chamber depth (ACD), thinnest corneal location, keratometry (anterior and posterior), cylinder, and axis. Repeatability was assessed using the coefficient of variation (CV). Intrasession reproducibility was assessed using intraclass correlation coefficient (ICC).
  
  
  RESULTS
  Coefficient of variation of 2% and less was observed for ACA, ACD, thinnest corneal location, and anterior keratometry. Intraclass correlation coefficients were high for ACA, ACD, anterior keratometry measurements and moderate for anterior cylinder and axis. Higher CV with relatively low ICC values was noticed with ACV, posterior keratometry measurements, and posterior cylinder, and axis. The last 2 have the highest CV and lowest ICC: 48.79% (range: 37.64%-59.95%) and 0.38%, respectively.
  
  
  CONCLUSIONS
  The Sirius Scheimpflug system has a very high repeatability and intrasessional reproducibility when measuring the ACD, ACA, anterior curvature parameters, and the thinnest corneal location. Thus, it can be used with confidence in clinical practice.
authors.affiliation: Department of Ophthalmology (M.M.), Francais Saint Vincent De Paul Hospital, Nazareth, Israel; Department of Ophthalmology (E.L., I.B.), Rabin Medical Center, Petach Tikva, Israel; Tel Aviv University (I.B.), Tel Aviv, Israel; and Assuta Optic Laser Center (I.B.), Tel Aviv, Israel.
authors.forename: Muhannad
authors.initials: M
authors.lastname: Masoud
authors.forename: Eitan
authors.initials: E
authors.lastname: Livny
authors.forename: Irit
authors.initials: I
authors.lastname: Bahar
mesh_terms: D000293:Adolescent; D000328:Adult; D000869:Anterior Eye Segment / Q000033:anatomy & histology*; D019781:Corneal Topography / Q000379:methods; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010781:Photography / Q000295:instrumentation*; D015203:Reproducibility of Results; D055815:Young Adult