Retrospective Analysis of Wavefront-Optimized Myopic LASIK: Comparison of Preoperative to Postoperative Astigmatism and High Order Aberrations: Trefoil and Coma Specifically: Could Topography-Guided Original Customization Had Addressed the Above?

Abstract

Purpose: The purpose of this retrospective study was to evaluate and analyze visual outcomes by recording pre and postoperative trefoil, coma and refractive astigmatism in wavefront optimized myopic LASIK. Methods: In this retrospective case review 200 eyes (one hundred patients) that had undergone myopic (with corresponding astigmatism) wavefront-optimized LASIK using the FS200 femtosecond and EX500 excimer lasers (Alcon/Wavelight, Erlagen, Germany) were evaluated. The 12 months post-operative UDVA and CDVA, low (myopia and/or astigmatism) along with high order aberration C6 to C9 changes were compared to the pre-operative values. Pre-operative topography data were available and used to generate for this study hypothetical treatment data (low and high order aberrations) if Topography-Guided (TG) with TMR cylinder amount and axis adjustment was used instead of the actual WFO. Results: Mean values at 12 months: UDVA of 20/22 and CDVA of 20/20. The postoperative refractive error in Diopters was -0.20±0.46 sphere and – 0.45±0.27 cylinder. The average absolute value for the high order aberrations studied were pre-op: C6: 0.10±0.12, C7: 0.19±0.16, C8: 0.15±0.12, C9: 0.09±0.09 μm and respectively post-op, C6: 0.11±0.10, C7: 0.46±0.38, C8: 0.34±0.30, C9: 0.11±0.13 μm. If topography-guided customization with TMR was originally employed an addition mean -0.36D of astigmatism would have been attempted. Conclusion: Wavefront optimized ablations do not address HOA, pre-existing trefoil (C6, C9) in this group essentially did not change while coma (C7 and C8) increased despite the essential achievement of emmetropia. In theory topography-guided customization with TMR may had offered improved C7 and -C8 outcomes, along with superior cylindrical correction.