高度近视行SMILE与FS-LASIK术后早期角膜体积及厚度空间分布的变化

Early Changes in Corneal Volume and Corneal Thickness Spatial Profile after SMILE and FS-LASIK for High Myopia

目的:基于角膜体积(CV)、角膜厚度空间分布(CTSP)及角膜厚度变化率(PTI)情况探讨高度近视眼行飞秒激光小切口角膜基质透镜取出术(SMILE)或飞秒激光辅助准分子激光原位角膜磨镶术(FS-LASIK)术后早期的角膜变化。方法:回顾性研究。连续纳入2020年12月至2022年12月在浙江大学医学院附属第二医院眼科中心行角膜屈光手术且完成6个月随访的高度近视患者46例(92眼),根据手术方式不同分为SMILE组23例(46眼)和FS-LASIK组23例(46眼)。采用Pentacam眼前节分析仪测量术前及术后1、3、6个月的CV和角膜中央、最薄点及直径2、4、6 mm同心圆上的角膜厚度(CT),并计算PTI。采用Friedman检验对术后不同时间点的CV、CTSP和PTI进行重复测量分析,并利用多元线性回归分析高度近视患者术后早期PTI与性别、年龄、手术方式、术前中央角膜厚度及眼压的相关性。结果:SMILE组中,与术后1个月相比,术后3个月角膜中央、最薄点及2、4、6 mm同心圆上CT明显增加(Z=-3.49~-2.75,P<0.01);术后6个月与术后1个月相比,CV明显增加(Z=-2.51,P=0.012),角膜中央、最薄点及2、4、6 mm同心圆上CT明显增加(Z=-3.98~-2.97,P<0.01),2、4、6 mm同心圆上的PTI明显下降(Z=-3.90~-2.11,P<0.05)。FS-LASIK组中,与术后1个月相比,术后3个月角膜中央、最薄点和2、4 mm同心圆上CT明显增加(Z=-3.40~-2.26,P<0.05),4、6 mm同心圆上的PTI明显下降(Z=-2.54,P=0.011;Z=-1.97,P=0.049);术后6个月与术后1个月相比,角膜中央、最薄点和2、4 mm同心圆上CT明显增加(Z=-4.19~-2.70,P<0.01),2、4、6 mm同心圆上的PTI明显下降(Z=-3.37~-2.26,P<0.05)。2组术后6个月与术后3个月相比,CV、CTSP及PTI差异均无统计学意义(均P>0.05)。多元线性回归分析表明,相较于SMILE组,FS-LASIK组术后6个月2、4 mm同心圆上的PTI更高(β=0.55,95%可信区间:0.15~0.94,P=0.008;β=1.44,95%可信区间:0.37~2.52,P=0.009)。结论:高度近视患者行SMILE与FS-LASIK术后3个月内CT增加,CV变化不明显,术后3~6个月CV、CT及PTI的变化均趋于稳定。相较于SMILE组,FS-LASIK组PTI在术后更高,且术后3个月内变化明显。

Objective:To evaluate the early corneal alternations after small incision lenticule extraction(SMILE)and femtosecond laser-assisted in situ keratomileusis(FS-LASIK)for high myopia patients based on the corneal volume(CV),corneal thickness spatial profile(CTSP),and percentage of thickness increase(PTI).Methods:This retrospective study included 46 participants(92 eyes)with high myopia who underwent corneal refractive surgery at Eye Center,the Second Affiliated Hospital,Zhejiang University School of Medicine from December 2020 to December 2022 and completed 6-month follow-up.Participants in this study were divided into the SMILE group(23 patients,46 eyes)and the FS-LASIK group(23 patients,46 eyes)according to the surgical procedures.Pre-and post-operative(1,3,6 months)CV and corneal thickness(CT)on the central,thinnest point,and 2,4,6 mm diameter concentric circles of the subjects were measured by Pentacam anterior segment analyzer,and the PTI was also calculated.Repeated measurements of CV,CTSP,and PTI at different postoperative time points were analyzed using Friedman's test,and the correlation of gender,age,surgical procedure,preoperative central corneal thickness,and intraocular pressure with the postoperative PTI was analyzed using multiple linear regression.Results:In the SMILE group,CT at the central,thinnest point and 2,4,6 mm concentric circles were significantly increased at 3 months compared to that at 1 month(Z=-3.49--2.75,P<0.01).CV(Z=-2.51,P=0.012)and CT at the central,thinnest point,and 2,4,6 mm concentric circles were significantly increased(Z=-3.98--2.97,P<0.01)at 6 months compared with 1 month,while PTI at 2,4,6 mm concentric circles(Z=-3.90--2.11,P<0.05)were decreased.In the FS-LASIK group,CT at the center,thinnest point,and 2 mm,4 mm concentric circles were significantly increased at 3 months compared to that at 1 month(Z=-3.40--2.26,P<0.05),while PTI at 4 mm and 6 mm concentric circles were decreased(Z=-2.54,P=0.011;Z=-1.97,P=0.049);CT at the center,thinnest point,and 2,4 mm concentric circles were significantly elevated at 6 months compared with 1 month(Z=-4.19--2.70,P<0.01),whereas PTI at 2,4,6 mm concentric circles were reduced(Z=-3.37--2.26,P<0.05).Alternations in CV,CTSP and PTI were not statistically significant at 6 months postoperatively compared to 3 months(all P>0.05)in both groups.The multiple linear regression showed that the PTI on the 2 mm and 4 mm concentric rings was higher in the FS-LASIK group compared to the SMILE group at 6 months postoperatively(β=0.55,95%CI:0.15-0.94,P=0.008;β=1.44,95%CI:0.37-2.52,P=0.009).Conclusions:After SMILE and FS-LASIK for patients with high myopia,CT increased significantly,but CV altered insignificantly within 3 months.And alternations in CV,CT and PTI stabilized between 3 and 6 months.Compared to the SMILE group,the PTI in the FS-LASIK group was higher postoperatively and altered significantly within 3 months.