title: Clinical comparison of 6 aberrometers. Part 2: statistical comparison in a test group.
abstract: OBJECTIVE
  To compare and mutually validate the measurements of 6 aberrometers: the Visual Function Analyzer (Tracey), the OPD-Scan (ARK-10000, Nidek), the Zywave (Bausch & Lomb), the WASCA (Carl Zeiss Meditec), the MultiSpot Hartmann-Shack device, and the Allegretto Wave Analyzer.
  
  
  METHODS
  University Hospital Antwerp, Antwerp, Belgium.
  
  
  METHODS
  This prospective study was conducted on a group of 44 healthy eyes with refractions ranging from -5.25 diopters (D) to +5.25 D (cylinder 0 to -2 D). For each aberrometer and each eye, the averaged Zernike data were used to calculate various kinds of root-mean-square (RMS). These parameters, together with the refractive parameters, were then analyzed with a repeated-measures analysis of variance (ANOVA) test, complemented by paired t tests. A similar analysis was done for the comparison of the variances of these parameters.
  
  
  RESULTS
  The aberrometers gave comparable values for all studied parameters with the following exceptions: The OPD-Scan underestimated the polynomials describing 4- and 5-fold symmetries, and the Visual Function Analyzer slightly overestimated the astigmatism terms. The 3rd-order radial RMS value was different for each device, as well as the RMS in the central 2.0 mm zone. The WASCA presented the lowest variance.
  
  
  CONCLUSIONS
  These results suggest that in healthy eyes, all aberrometers produced globally similar results but they may vary in some details.
authors.affiliation: Vision Lab, University of Antwerp, Belgium. jos.rozema@ua.ac.be
authors.forename: Jos J
authors.initials: JJ
authors.lastname: Rozema
authors.forename: Dirk E M
authors.initials: DE
authors.lastname: Van Dyck
authors.forename: Marie-José
authors.initials: MJ
authors.lastname: Tassignon
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000175:diagnosis*; D003315:Cornea / Q000473:pathology*; D006801:Humans; D016014:Linear Models; D011446:Prospective Studies; D012029:Refraction, Ocular; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014787:Vision Tests / Q000295:instrumentation* / Q000592:standards