Reproducibility of wavefront measurements using the LADARWave aberrometer.
OBJECTIVE
To test reproducibility of lower and higher order aberration measurements using the Alcon LADAR-Wave system.


METHODS
Measurements were obtained using the LADARWave aberrometer from 100 eyes (50 patients) who presented for refractive surgery. Each patient underwent 2 separate examinations a minimum of 1 day apart. Zernike polynomial values for these 2 separate measurements were recorded based on a calculated pupil size of 6.5 mm; reproducibility was assessed by analyzing the mean difference between the 2 measurements.


RESULTS
The mean difference for defocus was 0.17 +/- 0.12 microm, which represented 2.6% +/- 1.9% of the mean defocus value (6.33 microm). The mean difference for astigmatism was 0.11 +/- 0.12 microm, which represented 23% +/- 26% of the mean astigmatism value (0.45 microm). The mean difference for coma was 0.06 +/- 0.06 microm, which represented 37% +/- 37% of the mean coma value (0.16 microm). The mean difference for spherical aberration was 0.04 +/- 0.04 microm, which represented 18% +/- 18% of the mean spherical aberration value (0.22 microm).


CONCLUSIONS
Measurements for defocus were reproducible whereas measurements of astigmatism and higher order aberrations were more variable. The absolute root-mean-square differences between measurements were small, despite the many possible sources of error and variability. Surgical outcomes suggest that the LADARWave aberrometer is measuring at an appropriate clinical resolution.
Lewis
Craig D
CD
Cole Eye Institute, Cleveland Clinic Foundation, Cleveland, Ohio, USA. lewisc2@ccf.org
Krueger
Ronald R
RR
D003941:Diagnostic Techniques, Ophthalmological; D006801:Humans; D007091:Image Processing, Computer-Assisted; D012030:Refractive Errors / Q000175:diagnosis*; D015203:Reproducibility of Results; D012189:Retrospective Studies