title: Central corneal thickness measurement with the Pentacam Scheimpflug system, optical low-coherence reflectometry pachymeter, and ultrasound pachymetry.
abstract: OBJECTIVE
  To assess the intraoperator repeatability and interoperator reproducibility of central corneal thickness measurements by the Pentacam Scheimpflug imaging system (Oculus) and the optical low-coherence reflectometer (OLCR) pachymeter (Haag-Streit) and to compare them with those of ultrasound (US) pachymetry.
  
  
  METHODS
  Assaf Harofe Medical Center Ophthalmology Outpatient Clinic, Zerifin, Israel.
  
  
  METHODS
  Repeatability was determined from 10 successive measurements in each of 4 healthy patients. Reproducibility for the Pentacam Scheimpflug system was determined from measurements by 2 operators in each of 24 patients; in these 24 patients, central corneal thickness measurements were compared between the Pentacam and US pachymetry. For the OLCR pachymeter, reproducibility was determined from measurements by 2 operators in each of 16 patients, in whom central corneal thickness was also measured with the Pentacam.
  
  
  RESULTS
  Mean coefficient of repeatability was 0.84% for the Pentacam Scheimpflug system and 0.33% for the OLCR pachymeter. For the Pentacam, the coefficient of interoperator reproducibility was 1.10% and the 95% limits of agreement were -10.2 microm to +11.9 microm. Mean difference between Pentacam and US was 6.09 microm. For the OLCR pachymeter, the coefficient of interoperator reproducibility was 0.59% and the 95% limits of agreement were -5.4 microm to +7.0 microm. Mean difference between central corneal thickness values obtained with the OLCR pachymeter and Pentacam Scheimpflug system was 1.7 microm.
  
  
  CONCLUSIONS
  Objective, noncontact measurement of central corneal thickness with the Pentacam Scheimpflug system and OLCR pachymeter was convenient and yielded excellent intraoperator repeatability and interoperator reproducibility. Central corneal thickness values obtained with the Pentacam were similar to those obtained with both the OLCR pachymeter and an US pachymeter. Further research is needed to corroborate whether central corneal thickness measurements by the Pentacam and OLCR devices can be used interchangeably and are more clinically useful than US pachymetry.
authors.affiliation: Department of Ophthalmology, Assaf Harofe Medical Center, Beer Yaacov, Zerifin, Israel.
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Barkana
authors.forename: Yariv
authors.initials: Y
authors.lastname: Gerber
authors.forename: Uri
authors.initials: U
authors.lastname: Elbaz
authors.forename: Shulamit
authors.initials: S
authors.lastname: Schwartz
authors.forename: Gie
authors.initials: G
authors.lastname: Ken-Dror
authors.forename: Isaac
authors.initials: I
authors.lastname: Avni
authors.forename: David
authors.initials: D
authors.lastname: Zadok
mesh_terms: D001699:Biometry / Q000379:methods; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D009929:Organ Size; D010781:Photography / Q000379:methods*; D015203:Reproducibility of Results; D014463:Ultrasonography; D014741:Video Recording