title: [Agreement and repeatability of central corneal thickness measurement using the Pentacam and ultrasound pachymetry].
abstract: OBJECTIVE
  To compare the agreement and repeatability of the OCULUS Pentacam (a new Scheimpflug-based imaging system) with ultrasound pachymetry in the measurement of central corneal thickness (CCT).
  
  
  METHODS
  Central corneal thickness was measured in 112 subjects (112 eyes) separately by two examiners, first using the Pentacam instrument, then using an ultrasonic pachymetry. Measurements were repeated 3 times for each pachymetry.
  
  
  RESULTS
  Mean values of CCT for each instrument were (538.63 ± 31.55) µm and (541.02 ± 30.45) µm using the Pentacam and the ultrasonic pachymeter, respectively. The difference is significant between the two instruments (t = -3.414, P = 0.001), the mean value of the difference is (-2.39 ± 7.42) µm. The Bland-Altman Plots displayed relatively good agreement (limits of agreement were -16.93 µm to 12.15 µm) between the two instruments. The intraclass correlation coefficient (ICC) of the two devices showed high repeatability (Separately 0.86 and 0.88).
  
  
  CONCLUSIONS
  The agreement between the Pentacam instrument and the ultrasonic pachymetry was good, and the repeatability was also good for both instruments independently, however it is needed to increase measure times to improve the repeatability of the Pentacam which is a promising new instrument for anterior eye evaluation.
authors.affiliation: Department of Ophthalmology, People's Hospital of Leshan, Leshan 614000, China. yiyou12@sina.com
authors.forename: Geng-Sheng
authors.initials: GS
authors.lastname: Hao
authors.forename: Li
authors.initials: L
authors.lastname: Zeng
authors.forename: Yu-Ru
authors.initials: YR
authors.lastname: Li
authors.forename: Dan
authors.initials: D
authors.lastname: Shui
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D006801:Humans; D008297:Male; D015203:Reproducibility of Results; D014463:Ultrasonography; D055815:Young Adult