Comparison of myopic astigmatic correction after cross-assisted SMILE, FS-LASIK, and transPRK

Abstract

Purpose: To compare astigmatic correction among cross-assisted small incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK), and transepithelial photorefractive keratectomy (T-PRK). Setting: The Eye Hospital of Wenzhou Medical University, Zhejiang, China. Design: Prospective comparison study. Methods: This study included 154 right eyes of 154 patients with astigmatism of -1.00 to -2.75 diopters (D). 64, 42, and 48 eyes were receiving SMILE, FS-LASIK, and T-PRK, respectively. The SMILE group used cross-axis alignment for head positioning for astigmatism correction. In the FS-LASIK and T-PRK groups, static and dynamic cyclotorsion control were used. Changes in ocular parameters and vector analysis were assessed six months postoperatively. Results: The safety and efficacy indices were comparable among the three groups six months after surgery. Residual astigmatism was smallest in the SMILE group (-0.23±0.25 D) compared to that in FS-LASIK (-0.40±0.28 D, P = 0.009) and T-PRK groups (-0.42±0.32 D, P = 0.001). Respectively, 53 (82.8%), 36 (85.7%), and 37 (77.1%) eyes achieved an angle of error within ±5° (P = 0.55). Notably, vector analysis showed that the difference vector, the magnitude of the error, and its absolute value were significantly smaller in the SMILE group than those in the other groups (P < 0.05). Additionally, the higher-order aberrations, especially coma, were significantly induced after surgery in each group (P < 0.001). Conclusions: Residual astigmatism magnitude was smallest by cross-assisted SMILE, followed by FS-LASIK and T-PRK, and the astigmatism axial correction was comparable among groups.

Effect of Cyclotorsion Compensation in Small Incision Lenticule Extraction Surgery for the Correction of Myopic Astigmatism: A Systematic Review and Meta-Analysis

“…This is reflected as a repeated counterclockwise deviation from the intended axis, which may be attributed to mild torsional eye movements during suction application. This finding aligns with the outcomes observed by Yang et al [ 34 ]. Zhao et al also demonstrated that wavefront-guided FS-LASIK and optimized SMILE achieved comparable outcomes in terms of astigmatism correction.…”