Intraocular lens power calculation accuracy after keratorefractive lenticule extraction with the novel ESCRS post-keratorefractive surgery calculator

Purpose: To compare IOL power calculation accuracy after keratorefractive lenticule extraction (KLEx) using the ESCRS online calculator versus ray tracing, the current gold standard. Setting: Multicenter study at Ludwig-Maximilians-University Eye Hospital (Munich, Germany) and SMILE Eyes Clinics (Germany, Austria). Design: Multicenter, cross-sectional study. Methods: Patients who underwent SMILE (KLEx) and subsequent cataract surgery were included. Post-hoc IOL power calculations were performed using ray tracing (Okulix) and the ESCRS calculator (Barrett True-K post-LVC, Hoffer-QST post-LVC, EVO post-LVC). Accuracy, trueness, and precision were compared descriptively. Results: Seven eyes from seven patients were analyzed. EVO post-LVC showed the lowest mean error (-0.24±0.50D), followed by ray tracing (-0.28±0.32D) and Hoffer-QST post-LVC (-0.36±0.59D). Ray tracing, EVO post-LVC and Barrett True-K post-LVC achieved 100% accuracy within ±1.00D. Ray tracing had the lowest mean absolute error (0.35D). Conclusions: Ray tracing and ESCRS post-LVC formulas improve IOL power calculations, emphasizing the need for tailored approaches in post-KLEx eyes.