Chen Wen, Bao FangJun, Roberts Cynthia J, Zhang Jia, Wang Chong, Li XueFei, Wang JunJie, Abu Said Anas Ziad Masoud, Mayopa Kevin Nguelemo, Chen YaNi, Zheng XiaoBo, Eliasy Ashkan, Elsheikh Ahmed, Chen ShiHao
National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China.
National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China.
Front Bioeng Biotechnol. 2024 Mar 15;12:1323612. doi: 10.3389/fbioe.2024.1323612. eCollection 2024.
To evaluate the change in corneal biomechanics in patients with postoperative ectasia risk when combining two common laser vision correction procedures (tPRK and FS-LASIK) with cross-linking (in tPRK Xtra and FS-LASIK Xtra). The study included 143 eyes of 143 myopic, astigmatic patients that were divided into non-cross-linked refractive surgery groups (non-Xtra groups, tPRK and FS-LASIK) and cross-linked groups (Xtra groups, tPRK Xtra and FS-LASIK Xtra) according to an ectasia risk scoring system. The eyes were subjected to measurements including the stress-strain index (SSI), the stiffness parameter at first applanation (SP-A1), the integrated inverse radius (IIR), the deformation amplitude at apex (DA), and the ratio of deformation amplitude between apex and 2 mm from apex (DARatio2mm). The measurements were taken preoperatively and at 1, 3, and 6 months postoperatively (pos1m, pos3m, and pos6m). Posterior demarcation line depth from the endothelium (PDLD) and from the ablation surface (DLA) were recorded at pos1m. SP-A1 significantly decreased, while IIR, deformation amplitude, and DARatio2mm increased significantly postoperatively in all four groups ( < 0.01)-all denoting stiffness decreases. In the FS-LASIK group, the changes in IIR, DA, and DARatio2mm were 32.7 ± 15.1%, 12.9 ± 7.1%, and 27.2 ± 12.0% respectively, which were significantly higher ( < 0.05) compared to 20.1 ± 12.8%, 6.4 ± 8.2%, and 19.7 ± 10.4% in the FS-LASIK Xtra group. In the tPRK group, the change in IIR was 27.3 ± 15.5%, significantly larger than 16.9 ± 13.4% in the tPRK Xtra group. The changes of SSI were minimal in the tPRK (-1.5 ± 21.7%, = 1.000), tPRK Xtra (8.4 ± 17.9%, = 0.053), and FS-LASIK Xtra (5.6 ± 12.7%, = 0.634) groups, but was significant in the FS-LASIK group (-12.1 ± 7.9%, < 0.01). After correcting for baseline biomechanical metrics, preoperative bIOP and the change in central corneal thickness (△CCT) from pre to pos6m, the changes in the IIR in both FS-LASIK and tPRK groups, as well as DA, DARatio2mm and SSI in the FS-LASIK group remained statistically greater than their corresponding Xtra groups (all < 0.05). Most importantly, after correcting for these covariates, the changes in DARatio2mm in the FS-LASIK Xtra became statistically smaller than in the tPRK Xtra ( = 0.017). The statistical analysis results indicate that tPRK Xtra and FS-LASIK Xtra effectively reduced the biomechanical losses caused by refractive surgery (tPRK and FS-LASIK). The decrease in corneal overall stiffness was greater in FS-LASIK than in tPRK, and the biomechanical enhancement of CXL was also higher following LASIK than after tPRK.
为评估在有术后扩张风险的患者中，将两种常见的激光视力矫正手术（经上皮准分子原位角膜磨镶术[tPRK]和飞秒激光制瓣准分子原位角膜磨镶术[FS-LASIK]）与交联术（tPRK Xtra和FS-LASIK Xtra中的交联术）联合应用时角膜生物力学的变化。该研究纳入了143例近视、散光患者的143只眼，根据扩张风险评分系统将其分为非交联屈光手术组（非Xtra组，tPRK和FS-LASIK）和交联组（Xtra组，tPRK Xtra和FS-LASIK Xtra）。对这些眼睛进行了多项测量，包括应力应变指数（SSI）、首次压平处的刚度参数（SP-A1）、综合逆半径（IIR）、顶点处的变形幅度（DA）以及顶点与距顶点2mm处的变形幅度之比（DARatio2mm）。测量在术前以及术后1个月、3个月和6个月（术后1个月[pos1m]、术后3个月[pos3m]和术后6个月[pos6m]）进行。在术后1个月记录从内皮到后分界线的深度（PDLD）以及从消融表面到后分界线的深度（DLA）。在所有四组中，术后SP-A1显著降低，而IIR、变形幅度和DARatio2mm显著增加（<0.01），所有这些都表明刚度降低。在FS-LASIK组中，IIR、DA和DARatio2mm的变化分别为32.7±15.1%、12.9±7.1%和27.2±12.0%，与FS-LASIK Xtra组的20.1±12.8%、6.4±8.2%和19.7±10.4%相比显著更高（<0.05）。在tPRK组中，IIR的变化为27.3±15.5%，显著大于tPRK Xtra组的16.9±13.4%。在tPRK组（-1.5±21.7%，P = 1.000）、tPRK Xtra组（8.4±17.9%，P = 0.053）和FS-LASIK Xtra组（5.6±12.7%，P = 0.634）中，SSI的变化最小，但在FS-LASIK组中显著（-12.1±7.9%，P<0.01）。在校正基线生物力学指标、术前眼压（bIOP）以及术前至术后6个月中央角膜厚度的变化（△CCT）后，FS-LASIK组和tPRK组中IIR的变化，以及FS-LASIK组中DA、DARatio2mm和SSI的变化在统计学上仍大于其相应的Xtra组（均P<0.05）。最重要的是，在校正这些协变量后，FS-LASIK Xtra组中DARatio2mm的变化在统计学上变得小于tPRK Xtra组（P = 0.017）。统计分析结果表明，tPRK Xtra和FS-LASIK Xtra有效减少了屈光手术（tPRK和FS-LASIK）导致的生物力学损失。FS-LASIK中角膜整体刚度的降低大于tPRK，并且交联术（CXL）在LASIK术后的生物力学增强也高于tPRK术后。
