This content from the 2020 ASCRS Virtual Annual Meeting is only available to ASCRS members. To log in, click the teal "Login" button in the upper right-hand corner of this page.
To identify the laser programming strategy that would theoretically achieve optimal visual outcomes of LASIK with a topography-guided laser in eyes with a disparity between cylinder measured by manifest refraction and cylinder measured by topography.
Data on 51 eyes undergoing topography-guided LASIK with the Wavelight Contoura excimer laser in which the preoperative refractive cylinder and the cylinder measured by the WaveLight® Topolyzer™ VARIO differed by 0.50D and/or 10 degrees were contributed by six surgeons at 5 clinical sites. Vector analysis of postoperative cylindrical refractive error and the actual laser programming strategy was used to calculate the cylindrical correction that would, theoretically, have completely eliminated postoperative refractive cylinder. This was compared to calculated results using the preoperative manifest refraction, the topographic cylinder, and the cylinder specified by Phorcides Analytic Engine.
The poorest calculated outcomes were obtained with the manifest refraction and the best with the topographically measured refraction or with Phorcides.
Using the preoperative refractive cylinder as the basis for correction with the Contoura ablation profile does not produce as desirable theoretical, calculated refractive outcomes as does entry of the topographically-measured refraction or the cylinder selected by Phorcides.