Randomized comparison of custom laser in situ keratomileusis with the Alcon CustomCornea and the Bausch & Lomb Zyoptix systems: one-month results

PURPOSE: To compare the early visual results of custom laser in situ keratomileusis (LASIK) outcomes for two different excimer laser systems. METHODS: This is a preliminary report of an ongoing prospective study that evaluated 30 patients (60 eyes) who were randomized to one of two custom LASIK treatment groups: 15 patients (30 eyes) with the Alcon CustomCornea laser system (Alcon Laboratories Inc, Fort Worth, Tex) and 15 patients (30 eyes) with the Bausch & Lomb Zyoptix laser system (Bausch & Lomb, Rochester, NY). These matched patients were required to qualify for treatment with both custom laser systems. All flaps were created with the IntraLase femtosecond laser (IntraLase Corp, Irvine, Calif) using a superior hinge. Early outcome measures are uncorrected visual acuity (UCVA) at 1 day, 1 week, and 1 month postoperative; manifest refractions at 1-month follow-up; and a comparison of 1-month postoperative UCVA to preoperative best spectacle-corrected visual acuity (BSCVA). Wavefront, topography, contrast sensitivity, and subjective questionnaires were also performed and will be reported after 3-month follow-up. RESULTS: At 1 month, the percentage of eyes with UCVA of 20/20 and 20/40 were similar with 93% and 100%, respectively, for CustomCornea eyes and 90% and 97%, respectively, for Zyoptix eyes. A difference between the two groups is in the percentage of eyes with UCVA of 20/16, 20/12.5, and 20/10 with 80%, 47%, and 13%, respectively, for CustomCornea and 70%, 10%, and 0%, respectively, for Zyoptix. The mean residual spherical equivalent refraction was +0.01 +/- 0.34 diopters (D) for CustomCornea and -0.04 +/- 0.38 D for Zyoptix. The two groups are similar at +/-1.00 D of intended correction, with CustomCornea 100% and Zyoptix 97%. However, +/-0.25 D the CustomCornea group was 10% more accurate at 73% versus 63% for the Zyoptix group. The efficiency ratio (postoperative UCVA compared to preoperative BSCVA) was greater for the CustomCornea group at 20/20, 20/16,20/12.5, and 20/10 levels. CONCLUSION: Custom LASIK with CustomCornea and Zyoptix is safe and effective and produces excellent early visual outcomes. This study demonstrates that current standard metrics for reporting refractive surgery visual outcomes are not adequate for evaluating wavefront-guided laser vision correction procedures. Amending the standard reporting metrics to include visual outcomes at the 20/16, 20/12.5, and 20/10 levels; accuracy at the +/-0.25 D of attempted; and postoperative UCVA compared to preoperative BSCVA will improve our ability to analyze wavefront-guided outcomes.