Aspheric ablation with the Nidek EC-5000 CX II with OPD-Scan objective analysis.
PURPOSE: To analyze the efficacy, predictability, stability, and safety of laser in situ keratomileusis (LASIK) to correct myopia and myopic astigmatism using the Nidek EC-5000 CX II laser and the Customized Aspheric Transition Zone (CATz) profile. METHODS: We conducted a retrospective analysis of 100 eyes (50 patients) with myopic astigmatism. A CATz profile was used in all eyes (profile 4) with an ablation zone of 5 mm and a transition zone of 9 mm, using Nidek FinalFit software. RESULTS: Average patient age was 39 years (range 21 to 69 yr). Preoperative mean spherical equivalent refraction was -4.70 +/- 2.53 D (range -11.88 to -0.50 D), mean preoperative sphere was -4.31 +/- 2.53 D (range -11.25 to -0.25 D), and mean preoperative cylinder was -0.78 +/- 0.69 D (range -3.25 to 0). Postoperative mean spherical equivalent refraction at 6 months was 0.12 +/- 0.53 D (range -1.63 to +0.88 D), mean postoperative sphere was 0.02 +/- 0.56 D (range -1.50 to +2.00 D), and mean postoperative cylinder was -0.29 +/- 0.50 D (range 0 to -1.75 D). Uncorrected visual acuity was 6/6 or better in 58% (58 eyes) and better than 6/12 in 93% (93 eyes). CONCLUSION: LASIK with the Nidek EC-5000 CX II laser and the CATz profile was effective, reasonably predictable, stable, and safe for correction of myopic astigmatism with a spherical component between -0.25 and -11.25 D, and a cylindrical component up to 3.25 D, using the techniques in this study. Astigmatism was undercorrected with the current algorithm.