Comparing The Existing Myopic Keratorefractive Lenticule Extraction (KLEx) Platforms: A Narrative Review

Kerato-refractive lenticule extraction (KLEx) is an evolving technique in corneal refractive surgery. The objective of this narrative review is to compare laser settings, visual outcomes, and higher order aberrations (HOAs) across the five currently available myopic KLEx platforms, specifically SmartSight, corrective lenticule extraction for advanced refractive correction (CLEAR), smooth incision lenticular keratomileusis (SILK^TM), small incision lenticule extraction (SMILE^®), and SMILE Pro^®. A comprehensive literature search was conducted in April 2025 using the PubMed, Scopus, and Embase databases, focusing on publications related to SmartSight, CLEAR, SILK, and SMILE Pro. For SMILE, a representative set of sources was selected due to the volume of available data. In total, 26 articles were included for this review. At the 1-day follow-up, 79% of eyes using SmartSight achieved an uncorrected distance visual acuity of 20/20, compared to 63% using SILK. These findings suggest that low pulse energy and high pulse frequency contribute to improved early visual outcomes, though the lenticule cut pattern also plays an important role. At 6 months, CLEAR, SILK, SMILE, and SMILE Pro showed high predictability, with over 85% of eyes achieving a spherical equivalent within ± 0.50 D. All platforms demonstrated excellent cylindrical correction, as over 87% of eyes achieved outcomes within ± 0.50 D. HOAs increased across all platforms, with significant induction of vertical coma. Overall, the five platforms demonstrated safety, efficacy, and refractive stability. This narrative review provides an overview of the current KLEx platforms and their clinical performance to compare differences in laser parameters and the factors influencing visual recovery, astigmatism correction, and HOA induction.