Wavefront-guided Versus Standard Laser in situ Keratomileusis in Myopia Using a 213 nm Wavelength Solid-state Laser: Comparison of Higher-order Aberrations.

Purpose: To assess the accuracy, efficacy, stability and safety of laser in situ keratomileusis (LASIK) for myopia and compare the pre- and post-operative changes in higher-order aberrations after wavefront-guided (WF) and standard (STD) LASIK done using the Pulzar Z1, a 213-nm wavelength solid-state laser, and determine their effects on visual acuity and refractive outcomes. Methods: This a retrospective case series composed of 80 eyes (40 patients) that had LASIK in an out-patient refractive surgery center in Manila, Philippines. Outcome measured were pre and post-operative manifest refraction spherical equivalent (MRSE), uncorrected distance visual acuity (UDVA), best-corrected distance visual acuity (CDVA), keratometry, root-mean-square (RMS) values, flap and ablation related complications. Results: The mean UDVA improved from 20/400 pre-operatively to 20/25 post-operatively. Thirty six of the 40 eyes (90%) treated with STD LASIK and 39 of the 40 eyes (97.5%) treated with WF LASIK had UDVA of 20/30 or better at 1 year post-operatively. There was a significant decrease in spherical equivalent manifest refraction post-operatively in all patients. The average spherical equivalent at 1 year is -0.43D±0.64. After twelve months of follow-up, 85.5% (34 out of the 40 eyes) of those who underwent STD LASIK and 77.5% (31 out of 40 eyes) who underwent WF LASIK had postoperative manifest refractive spherical equivalent (MRSE) of -1.0 to +1.0D. The mean difference in the attempted versus achieved refraction was not significant between the 2 groups (p = 0.32). At 12 months post-operatively, seven eyes (17.5%) gained 1 line in the WF-guided LASIK, while the rest of the eyes either showed no change in CDVA or lost 1-2 Snellen lines. The total RMS generally increased postoperatively for WF LASIK while decreased for STD LASIK, but the mean RMS difference from the pre- and post-operative values between the 2 groups were not statistically significant. None of the eyes developed flap complications during the follow-up period. Conclusion: Refractive surgery using the Pulzar Z1 213-nm wavelength solid-state laser is an effective and safe procedure in the treatment of myopia. Wavefront-guided LASIK offers no advantage over STD LASIK in improving higher-order aberrations and in achieving better visual and refractive outcomes.