Comparative Effectiveness of VISUMAX 800 with KLEx and Femtosecond LASIK in the Treatment of Myopic Astigmatism

Purpose: To compare the visual and refractive outcomes of KLEx using the VISUMAX 800 femtosecond laser and FS-LASIK performed using the VISUMAX 800 femtosecond laser and the EX500 excimer laser in the treatment of myopic astigmatism. Setting: Single-center, private ophthalmology center. Design: Retrospective comparative study. Methods: A total of 237 eyes (133 KLEx , 104 FS-LASIK) were evaluated. Cyclotorsion alignment in KLEx was achieved using the Callisto Eye system integrated with VISUMAX 800. Refractive outcomes, vector analysis (Alpins method), and safety and efficacy indices were compared between groups at 1 and 6 months postoperatively. Results: At 6 months, both groups achieved comparable UDVA (0.01 ± 0.04 logMAR) and CDVA. Mean SE was closer to emmetropia in the KLEx group (–0.04 ± 0.18 D vs. –0.10 ± 0.15 D, p=0.007). Residual cylinder was lower in KLEx (–0.14 ± 0.19 D vs. –0.20 ± 0.20 D, p=0.010). Vector analysis showed lower DV in KLEx (0.14 ± 0.19 D vs. 0.21 ± 0.21 D, p=0.009), while FS-LASIK had a slightly higher correction index (CI: 1.02 vs. 0.97, p=0.005). Conclusions: Both KLEx and FS-LASIK performed using the VISUMAX 800 achieved excellent refractive outcomes, with KLEx procedures incorporating an image-guided static cyclotorsion alignment strategy and demonstrating excellent refractive and vector analysis results.