title: Comparison of central corneal thickness and anterior chamber depth measurements using three imaging technologies in normal eyes and after phakic intraocular lens implantation.
abstract: BACKGROUND
  The repeatability and interchangeability of imaging devices measuring central corneal thickness (CCT) and anterior chamber depth (ACD) are important in the assessment of patients considering refractive surgery. The purpose of this study was to investigate the agreement of CCT and ACD measurements using three imaging technologies in healthy eyes and in eyes after phakic intraocular lens implantation (pIOL).
  
  
  METHODS
  In this comparative study, CCT and ACD were measured using anterior segment optical coherence tomography (AS-OCT), Orbscan II, and Pentacam in 33 healthy volunteers (66 eyes) and 22 patients (42 eyes) after pIOL implantation. Intraobserver repeatability was evaluated for all three devices in the healthy volunteer group.
  
  
  RESULTS
  Pairwise comparison of CCT measurements showed significant differences between all devices (P < 0.001), except for the AS-OCT and Orbscan II in the healthy volunteer group (P = 0.422) and the Orbscan II and Pentacam in the pIOL group (P = 0.214). ACD measurements demonstrated significant differences between all pairwise comparisons in both groups (P < or = 0.001). Intraobserver reliability was high for CCT and ACD measurements in the healthy volunteer group, with coefficients of variation ranging from 0.6% to 1.2% and 0.4% to 0.5% respectively.
  
  
  CONCLUSIONS
  CCT and ACD measurements using AS-OCT, Orbscan II, and Pentacam demonstrated high intraobserver reliability. However, these devices should not be used interchangeably for measurements of CCT and ACD in healthy subject and patients after pIOL implantation.
authors.affiliation: Department of Ophthalmology, University Hospital Maastricht, P. Debyelaan 25, 6202 AZ, Maastricht, The Netherlands.
authors.forename: Muriël
authors.initials: M
authors.lastname: Doors
authors.forename: Lars P J
authors.initials: LP
authors.lastname: Cruysberg
authors.forename: Tos T J M
authors.initials: TT
authors.lastname: Berendschot
authors.forename: John
authors.initials: J
authors.lastname: de Brabander
authors.forename: Frenne
authors.initials: F
authors.lastname: Verbakel
authors.forename: Carroll A B
authors.initials: CA
authors.lastname: Webers
authors.forename: Rudy M M A
authors.initials: RM
authors.lastname: Nuijts
mesh_terms: D000328:Adult; D000368:Aged; D000867:Anterior Chamber / Q000033:anatomy & histology / Q000473:pathology*; D001837:Body Weights and Measures; D003315:Cornea / Q000033:anatomy & histology / Q000473:pathology*; D019781:Corneal Topography; D003941:Diagnostic Techniques, Ophthalmological; D005260:Female; D006801:Humans; D019654:Lens Implantation, Intraocular; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D054120:Phakic Intraocular Lenses; D010781:Photography; D011446:Prospective Studies; D015203:Reproducibility of Results; D041623:Tomography, Optical Coherence / Q000379:methods; D055815:Young Adult