背景:用于小切口微透镜提取(SMILE)的帽厚度设计在激光后视力矫正(后LVC)角膜生物力学中起作用。本研究旨在比较SMILE与110μm不同帽厚度的角膜生物力学特征。120μm,130μm用于近视和近视散光矫正。
方法:75例(146只眼)接受SMILE治疗的患者,设计的瓶盖厚度为110μm,120μm,和130μm于2020年8月至2021年11月在北京同仁医院眼科中心招募。视敏度,折射,术前测量角膜生物力学参数,术后1周和1、3、6个月。进行了Bonferroni校正或Kruskal-Wallis检验的单向方差分析(ANOVA),以比较不同组之间的参数。应用Bonferroni校正或Friedman检验的重复测量方差分析来比较不同随访时间内的参数。
结果:110μm组的非矫正视力仅在术后1周和1个月更好(P=0.012,0.037)。球面当量没有显著差异,在Corvis生物力学指数激光视力矫正(CBI-LVC)中也没有。所有参数在术后3个月达到稳定。术后1个月,120μm和130μm组的综合半径(IR)和变形幅度比2mm(DA比2mm)高于110μm组(P=0.019,0.002)。术后6个月Ambrósio相关厚度(ARTh)也是如此(P=0.011)。压平刚度参数A1(SP-A1),应力-应变指数(SSI),130μm组的生物力学校正眼压(bIOP)和中央角膜厚度(CCT)最高,其次是120μm组,术后3个月(P<0.001,P=0.030,P=0.027,P=0.008)和6个月(P<0.001,P=0.002,P=0.0023,P=0.001)分别为110μm组。
结论:使用130-μm帽,SMILE后的角膜硬度最大,接下来是120μm的盖子,然后110-μm帽。130μm帽在角膜生物力学和再治疗选择方面可能具有优势。SMILE设计的协议应在实践中定制。
BACKGROUND: The design of cap thickness for small incision lenticule extraction (SMILE) plays a role in post-laser vision correction (post-LVC) corneal biomechanics. This study aimed to compare the corneal biomechanical characteristics following SMILE with different cap thicknesses of 110 μm, 120 μm, and 130 μm for myopia and myopic astigmatism correction.
METHODS: Seventy-five patients (146 eyes) who underwent SMILE with designed cap thickness of 110 μm, 120 μm, and 130 μm were recruited at the Eye Center of Beijing Tongren Hospital between August 2020 and November 2021. Visual acuity, refraction, and corneal biomechanical parameters were measured preoperatively, 1 week and 1, 3, 6 months postoperatively. One-way analysis of variances (ANOVA) with Bonferroni correction or Kruskal-Wallis test was performed to compare the parameters among different groups. Repeated-measures analysis of variance with Bonferroni correction or Friedman test was applied for comparing the parameters within different follow-up times.
RESULTS: Uncorrected distance visual acuity of 110-μm group was better only at 1-week and 1-month postoperatively (P = 0.012, 0.037). There were no significant differences in spherical equivalent, nor in Corvis biomechanical index-laser vision correction (CBI-LVC). All the parameters reached stability at 3-month postoperatively. Integrated radius (IR) and deformation amplitude ratio 2 mm (DA ratio 2 mm) in 120-μm and 130-μm groups were higher than 110-μm group at 1-month postoperatively (P = 0.019, 0.002). So was Ambrósio relational thickness (ARTh) at 6-month postoperatively (P = 0.011). Stiffness parameter at applanation A1 (SP-A1), stress-strain index (SSI), biomechanically corrected intraocular pressure (bIOP) and central corneal thickness (CCT) were highest in 130-μm group, followed by 120-μm group, then 110-μm group at 3-month (P<0.001, P = 0.030, P = 0.027, P = 0.008) and 6-month (P<0.001, P = 0.002, P = 0.0023, P = 0.001) postoperatively.
CONCLUSIONS: The corneal stiffness following SMILE was greatest with 130-μm cap, followed by 120-μm cap, then 110-μm cap. 130-μm cap might have advantages in terms of corneal biomechanics and retreatment option. The SMILE-designed protocol should be customized in practice.