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

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 (transPRK). SETTING: The Eye Hospital of Wenzhou Medical University, Zhejiang, China. DESIGN: Prospective comparison study. METHODS: 154 right eyes of 154 patients with astigmatism of −1.00 to −2.75 diopters (D) were included in this study. 64 eyes, 42 eyes, and 48 eyes were receiving SMILE, FS-LASIK, and transPRK, respectively. The SMILE group used cross-axial alignment for head positioning for astigmatism correction. In the FS-LASIK and transPRK groups, static and dynamic cyclotorsion control were used. Changes in ocular parameters and vector analysis were assessed at 6 months postoperatively. RESULTS: The safety and efficacy indices were comparable among the 3 groups at 6 months postoperatively. Residual astigmatism was smallest in the SMILE group (−0.23 ± 0.25 D) compared with that in FS-LASIK (−0.40 ± 0.28 D, P = .009) and transPRK groups (−0.42 ± 0.32 D, P = .001). 53 (82.8%), 36 (85.7%), and 37 (77.1%) eyes achieved an angle of error within ±5 degrees, respectively (P = .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 < .05). In addition, the higher-order aberrations, especially coma, were significantly induced postoperatively in each group (P < .001). CONCLUSIONS: Residual astigmatism magnitude was smallest by cross-assisted SMILE, followed by FS-LASIK and transPRK, and the astigmatism axial correction was comparable among groups.