Clinical comparison of 6 aberrometers Part 2: Statistical comparison in a test group
Accepted 12 November 2004.
Purpose
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.
Setting
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.
Conclusion
These results suggest that in healthy eyes, all aberrometers produced globally similar results but they may vary in some details.
From the Vision Lab (J.J.R., D.E.M.V.D.) and Department of Ophthalmology (J.J.R., M.-J.T.), University of Antwerp, Antwerp, Belgium
Reprint requests to Jos J. Rozema, MSc, University Hospital Antwerp, Wilrijkstraat 10, 2650 Edegem, Belgium.
Sponsored by an ESCRS grant (2002) and a 2002 grant of the Belgian Fund for Research in Ophthalmology (2002).
No author has a financial or proprietary interest in any material or method mentioned.
The authors thank the companies—Nidek, Bausch & Lomb, Zeiss, WaveLight, and Tracey—and their Belgian representatives for temporarily providing their aberrometers for our study. The authors thank Michael Mrochen for the lending of the MultiSpot aberrometer and Andrei Larichev and Nikita Irochnikov for providing the necessary technical assistance.
ABSTRACT