Abstract:AIM: To evaluate corneal biomechanical changes before surgery and different postoperative time in patients with varying degrees of myopia undergoing either femtosecond laser in situ keratomileusis(FS-LASIK)or small incision lenticule extraction(SMILE)procedures by ocular response analyzer(ORA), and to investigate potential differences in how these two surgical techniques and varying degrees of myopia affect corneal biomechanical properties.
METHODS: Case series study. A total of 132 eyes that underwent FS-LASIK or SMILE surgery at Lanzhou Huaxia Eye Hospital between December 2023 and June 2024 were enrolled. Based on the surgical procedure, they were categorized into FS-LASIK and SMILE groups and further stratified into a high myopia group(-10.00 DRESULTS: The corneal biomechanical status in the FS-LASIK group and the SMILE group was well comparable. At 3 mo postoperatively, both the FS-LASIK and SMILE groups showed a significant increase in SE compared with preoperative values, whereas UCVA, CCT, and IOPcc were significantly decreased(all P<0.05). No statistically significant differences were observed in these parameters between the two groups(all P>0.05). At 1 d after surgery, both CH and CRF decreased significantly in the FS-LASIK and SMILE groups(all P<0.05). The reduction was more pronounced in the FS-LASIK group than in the SMILE group(P<0.05). By 1 and 3 mo postoperatively, CH and CRF in both groups exhibited recovery relative to early postoperative levels and tended to stabilize, though they remained lower than preoperative values(all P<0.05). Furthermore, the FS-LASIK group had lower CH and CRF than the SMILE group at these time points(all P<0.05). Within the SMILE group, the high myopia subgroup demonstrated more pronounced decreases in CH and CRF at 1 d and 1 wk after surgery compared with the moderate-to-low myopia subgroup(all P<0.05).CONCLUSION: Both FS-LASIK and SMILE procedures demonstrated good safety, predictability, and effectiveness postoperatively. However, both techniques resulted in reduced corneal biomechanical parameters, with FS-LASIK causing a more significant decrease. In the early postoperative period, patients in the high myopia group showed a more pronounced reduction in corneal biomechanics. By 3 mo after surgery, no statistically significant difference was observed in the effect of myopia degree on corneal biomechanical properties.
