title: Reliability of corneal and total wavefront aberration measurements with the SCHWIND Corneal and Ocular Wavefront Analyzers.
abstract: OBJECTIVE
  To evaluate the reliability of the SCHWIND Corneal and Ocular Wavefront Analyzers.
  
  
  METHODS
  This study comprised 115 eyes of 58 healthy volunteers (26 [44.8%] women and 32 [55.2%] men) with no corneal or lenticular pathologies and normal visual acuity. All eyes underwent three consecutive measurements by one examiner with the Corneal Wavefront Analyzer and the Ocular Wavefront Analyzer (Hartmann-Shack principle). Corneal wavefront errors were calculated using the topography data, a standard eye model, and ray tracing. The reliability was tested for 2nd, 3rd, and 4th order aberrations as mean values of the standard deviations for all measurements.
  
  
  RESULTS
  Mean patient age was 23 +/- 2.1 years. The mean refraction was -0.77 +/- 1.56 diopters (D) (range: +3.33 to -5.28 D). The repeatability test revealed a good reliability for both machines with a slightly better value for the Ocular Wavefront Analyzer for 3rd and 4th order higher order aberrations (P < .05, Wilcoxon test).
  
  
  CONCLUSIONS
  Wavefront measurements of corneal and total optical aberrations performed with the Corneal Wavefront Analyzer and the Ocular Wavefront Analyzer have good reliability. Both measurements are recommended prior to any refractive surgery treatment.
authors.affiliation: International Vision Correction Research Centre, Department of Ophthalmology, Ruprecht-Karls-University of Heidelberg, Heidelberg, Germany. mike.holzer@med.uni-heidelberg.de
authors.forename: Mike P
authors.initials: MP
authors.lastname: Holzer
authors.forename: Martin
authors.initials: M
authors.lastname: Sassenroth
authors.forename: Gerd U
authors.initials: GU
authors.lastname: Auffarth
mesh_terms: D000328:Adult; D003315:Cornea / Q000473:pathology*; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D012029:Refraction, Ocular / Q000502:physiology; D012030:Refractive Errors / Q000175:diagnosis*; D015203:Reproducibility of Results; D014792:Visual Acuity