title: Comparison of central corneal thickness measurements with a rotating scheimpflug camera, a specular microscope, optical low-coherence reflectometry, and ultrasound pachymetry in keratoconic eyes.
abstract: OBJECTIVE
  To compare central corneal thickness (CCT) measurements with a rotating Scheimpflug camera (RSC), noncontact specular microscopy (SM), optical low-coherence reflectometry (OLCR), and ultrasonic pachymetry (UP) in keratoconus (KC) patients.
  
  
  METHODS
  In this prospective study, four CCT measurements taken with an RSC, SM, OLCR, and UP were compared in 81 eyes of 44 consecutive KC patients. The KC patients were divided into four subgroups according to Amsler-Krumeich's KC classification.
  
  
  RESULTS
  The RSC and UP measurements of the CCT were not statistically significant in all the groups. Comparison of the SM vs. the OLCR measurements yielded statistically significant differences in all the KC patients and in all KC stages. In all the KC patients, RSC and OLCR showed a high correlation coefficient factor (r = 0.87, p = 0.000).
  
  
  CONCLUSIONS
  CCT measurements with RSC are comparable to those achieved with UP. Compared with the other devices, according to SM measurements, the central cornea is thicker in all keratoconic eyes and in all KC grades, and it is thinner according to OLCR. RSC, UP, SM, and OLCR should not be used interchangeably in keratoconic eyes.
authors.affiliation: Department of Ophthalmology, Faculty of Medicine, Dicle University , Diyarbakir , Turkey and.
authors.forename: Yasin
authors.initials: Y
authors.lastname: Cinar
authors.forename: Abdullah Kursat
authors.initials: AK
authors.lastname: Cingu
authors.forename: Fatih Mehmet
authors.initials: FM
authors.lastname: Turkcu
authors.forename: Tuba
authors.initials: T
authors.lastname: Cinar
authors.forename: Alparslan
authors.initials: A
authors.lastname: Sahin
authors.forename: Harun
authors.initials: H
authors.lastname: Yuksel
authors.forename: Seyhmus
authors.initials: S
authors.lastname: Ari
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003315:Cornea / Q000473:pathology*; D063171:Corneal Pachymetry / Q000295:instrumentation; D003941:Diagnostic Techniques, Ophthalmological / Q000295:instrumentation*; D005260:Female; D006801:Humans; D007368:Interferometry / Q000295:instrumentation; D007640:Keratoconus / Q000175:diagnosis*; D008297:Male; D008853:Microscopy / Q000295:instrumentation; D009929:Organ Size; D010781:Photography / Q000295:instrumentation; D011446:Prospective Studies; D055815:Young Adult
keywords: Central corneal thickness; keratoconus; pachymetry; reflectometry; scheimpflug camera