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A Comparison of CustomCornea Myopia Algorithms for Wavefront-Guided Laser In Situ Keratomileusis
Colin C. K. Chan, MD, FRANZCO;
Brian S. Boxer Wachler, MD
Arch Ophthalmol. 2008;126(8):1067-1070.
Objective To determine whether the new CustomCornea M3 (myopic astigmatism) algorithm places additional pulses in the periphery to counter excimer laser peripheral ablation inefficiency.
Methods Analysis of 25 myopic eyes of 18 patients that were within the approved indications for both the myopic astigmatism (M3) and myopic sphere (A7) algorithms. We analyzed ablation depth at peak and 4-mm, 6-mm, and 7-mm zone diameters for both the A7 and M3 algorithms.
Results The M3 algorithm programmed for more of an ablation at the peak and peripheral zones than the A7 algorithm (P < .001). Even accounting for the additional peak ablation, there was significantly greater ablation in the periphery with the M3 algorithm compared with the A7 algorithm (P < .001). The mean (SD) manifest sphere was –4.09 (1.90) diopters (D), the mean (SD) manifest cylinder was –0.60 (0.52) D, and the mean (SD) manifest spherical equivalent was –4.39 (1.92) D. The manifest sphere ranged from –1.00 to –7.50 D, the manifest cylinder from 0.00 to –1.25 D, and the manifest spherical equivalent from –1.50 to –8.25 D.
Conclusion The new CustomCornea M3 algorithm is programmed to perform additional ablation in the periphery to counter decreased pulse efficacy and the potential for induced spherical aberration.
Author Affiliations: Boxer Wachler Vision Institute, Beverly Hills, California.
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