飞秒激光与角膜板层刀辅助LASIK术后早期角膜生物力学变化的比较

Comparison of corneal biomechanical changes at early stage after femtosecond LASIK and microkeratome LASIK

目的:基于角膜基质床厚度/术前角膜厚度(residual corneal stroma thickness/corneal thickness,RCST/CT)的不同,比较飞秒激光辅助LASIK和角膜板层刀辅助LASIK术后早期角膜生物力学的变化。方法:选取190例379眼,其中飞秒激光辅助LASIK组94例187眼,角膜板层刀辅助LASIK组96例192眼。根据术后剩余RCST/CT的不同,将飞秒激光辅助LASIK组(FS-IK组)和角膜板层刀辅助LASIK组(M-IK组)各分为三组,IK-Ⅰ组(RCST/CT<55%)、IK-Ⅱ组(55%≤RCST/CT<60%)和IK-Ⅲ组(RCST/CT≥60%)。分别于术前、术后1mo和3mo应用眼反应分析仪(reichert ocular response analyzer,ORA)检测角膜滞后量(corneal hysteresis,CH)和角膜阻力因子(corneal resistance factor,CRF)。结果:不同手术方式(FS-IK与M-IK)比较,CH和CRF均无统计学差异(F=0.44,F=2.56,P=0.51,P=0.11)。不同的RCST/CT比较,CH和CRF均有统计学差异(F=103.03,128.48,P均<0.05)。Ⅰ组CH和CRF较Ⅱ组明显减小(P<0.05),Ⅱ组CH和CRF较Ⅲ组明显减小(P<0.05),Ⅰ组CH和CRF较Ⅲ组明显减小(P<0.05)。术前及术后不同时间比较,CH和CRF均有统计学差异(F=576.99,1162.06,P均<0.05)。术后1mo和3mo,CH和CRF均较术前明显减小(P<0.05),术后1mo和术后3mo比较,CH和CRF差异无统计学意义(P>0.05)。结论:无论是飞秒激光辅助LASIK还是角膜板层刀辅助LASIK在术后早期角膜生物力学参数均下降,但两种手术方式对角膜生物力学的影响无差异。

AIM： To compare the corneal biomechanical changes at early stage after femtosecond laser assisted in situ keratomi（ LASIK） and microkeratome LASIK according to different residual corneal stroma thickness /cornea thickness（ RCST/CT）.METHODS： Ninety- four patients（ 187 eyes） with femtosecond LASIK（ FS- IK） and 96 patients（ 192 eyes）with microkeratome LASIK（ M- IK） were included in this study. LASIK group was divided into three groups according to the ratio of RCST/CT,which were IK- I group（ RCST/CT 〈55%）,IK-Ⅱ group（ 55%≤RCST/CT〈60%） and IK- Ⅲ group（ RCST/CT≥60%）. Corneal hysteresis（ CH） and corneal resistance factor（ CRF） were measured by reichert ocular response analyzer（ ORA） at pre- operation,postoperative 1and 3mo.RESULTS： Compared with FS- IK and M- IK,there were no statistical difference in CH and CRF（ F =0. 44,F =2. 56,P = 0. 51,P = 0. 11）. Based on different RCST/CT,there were statistical differences in CH and CRF between group Ⅰ and group Ⅱ（ F = 103. 03,128. 48,P〈0. 05）,group Ⅱ and group Ⅲ（ P〈0. 05）,group Ⅰ and group Ⅲ（ P〈0. 05）. There were statistical differences in CH and CRF between pre- operation and different postoperative times（ F = 576. 99,1162. 06,P〈0. 05）. CH and CRF of postoperative 1mo and 3mo were significantly smaller than pre- operation（ P〈0. 05）,but there was no statistical difference between postoperative 1and 3mo（ P 0.05）.CONCLUSION： The biomechanical parameters decreased at early stage after femtosecond LASIK and microkeratome LASIK,but there is no statistical difference between femtosecond LASIK and microkeratome LASIK.The less the ratio of RCST/CT, the more effect on biomechanics.