Reproducibility of wavefront measurements using the LADARWave aberrometer

PURPOSE: To test reproducibility of lower and higher order aberration measurements using the Alcon LADARWave 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 μm, which represented 2.6%±1.9% of the mean defocus value (6.33 μm). The mean difference for astigmatism was 0.11±0.12 μm, which represented 23%±26% of the mean astigmatism value (0.45 μm). The mean difference for coma was 0.06±0.06 μm, which represented 37%±37% of the mean coma value (0.16 μm). The mean difference for spherical aberration was 0.04±0.04 μm, which represented 18%±18% of the mean spherical aberration value (0.22 μm). 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 clinteat resolution.