Retrospective comparison of 3 laser platforms to correct myopic spheres and spherocylinders using conventional and wavefront-guided treatments

Purpose

To compare 3 excimer laser platforms for the correction of myopic spheres and myopic spherocylinders using conventional algorithms or wavefront-guided treatments.

Setting

Private practice, in-office laser facility.

Methods

This retrospective comparative interventional case series comprised 458 patients (721 eyes). Sequentially selected patient eyes had laser in situ keratomileusis surgery by the same surgeon using 1 of 3 lasers (Visx Star S4, LADARVision 4000, WaveLight Allegretto) with a conventional algorithm or with wavefront-guided software. The same aberrometer was used before and after surgery in a given eye. A femtosecond laser (IntraLase Corp.) was used for flap creation. Parametric and nonparametric 1-way analysis of variance and regression analysis were performed. Outcomes were analyzed for change in visual, refractive, and wavefront categories.

Results

On average, all lasers improved uncorrected visual acuity and best spectacle-corrected visual acuity, produced predictable refractive change, and induced higher-order aberrations (HOAs). Overall, the Star S4 wavefront treatment improved results compared with Star S4 conventional treatment; however, LADARVision wavefront treatment did not improve the conventional results. The Allegretto produced the best results in the category of visual acuity in spherocylinder eyes only. The Star S4 wavefront treatment produced the best HOA results for sphere and spherocylinder. In the spherocylinder group, the LADARVision reduced astigmatism and defocus the most.

Conclusion

These results document that different laser platforms achieve statistically significantly different outcomes depending on refractive, patient, and surgical variables.