LASIK、Epi-LASIK、SBK、Fem-LASIK及SMILE术中角膜切削误差的对比研究

Studies on cutting errors of LASIK,EpiLASIK,SBK,Fem-LASIK and SMILE

目的调查四种准分子激光角膜切削术和飞秒微创透镜取出术(small incision lenticule extraction,SMILE)中的中央角膜厚度的切削误差及其变化规律,着重探讨不同手术方式对角膜切削误差的影响。方法收集行激光屈光手术的近视患者302例585眼。根据患者意愿分为5组,分别行准分子激光原位角膜磨镶术(LASIK,100眼)、机械法准分子激光上皮瓣下角膜磨镶术(Epi-LASIK,62眼)、准分子激光前弹力层下角膜磨镶术(sub-Bowman keratomieusis,SBK;184眼)、飞秒激光准分子激光原位角膜磨镶术(femtosecond laser-assisted LASIK,Fem-LASIK;165眼)及SMILE 74眼。使用A型超声角膜测厚仪测量所有眼术前及术后1个月的中央角膜厚度,计算中央角膜切削误差,并分析切削误差与手术方式、近视程度及手术前角膜厚度的关系。结果手术方式对角膜切削误差有显著的影响(P<0.001)。SMILE组中央角膜实际切削厚度与预期切削厚度基本一致,差异无统计学意义(均为P>0.05)。其中,中度近视眼的切削误差为(2.30±1.81)μm,高度近视眼的切削误差为(1.81±2.13)μm。其他四组中,中央角膜的实际切削厚度大于预期切削厚度,差异均具有统计学意义(均为P<0.05)。屈光不正程度对角膜切削误差也有一定的影响:在SBK组和Fem-LASIK组中,近视程度越严重,切削误差越大,相关关系达到了统计学上的显著性(均为P<0.01)。手术前中央角膜厚度对角膜切削误差基本没有影响(均为P>0.05)。结论激光屈光手术中影响中央角膜切削误差的主要因素是手术方式,在5种手术方式中,SMILE具有显著的优越性。

Objective To investigate the cutting error of five different types of laser eye surgery：laser-assisted in situ keratomileusis （LASIK） ,laser-assisted subepithe- lial keratomileusis （ Epi-LASIK）, sub-Bowman keratomileusis （ SBK）, femtosecond laser- assisted LASIK（Fem-LASIK） and small incision lenticule extraction （ SMILE ） and the varying pattern, and to explore the effect of surgery type on corneal cutting error. Methods Three hundred and two patients（585 eyes） who had been ready for laser- assisted refractive surgeries were collected and divided into 5 groups according to pa- tients＇ preferences ：100 eyes were in LASIK group,52 eyes were in Epi-LASIK group, 184 eyes were in SBK group, 155 eyes were in Fem-LASIK group,74 eyes were in SMILE group. Central corneal thickness was measured preoperatively and 1 month after the op- eration using type-A ultrasonic pachymeter. Cutting errors of central corneal were calcu- lated, and associations between cutting errors and surgery type, degree of myopia, pre- operative corneal were analyzed. Results Surgery type had a significant influence on corneal cutting errors （P 〈 0. 001 ）. The actual cutting thickness of central cornea in SMILE group was nearly same with expected results（ All P 〉 0.05 ） ;The cutting error in patients with medium myopia was（ 2.30 ± 1.81 ） μm, while that in patients with high my- opia was（ 1.81 ±2.13） μm. The actual cutting thicknesses of central cornea in the other 4 groups were significantly higher than expected results （All P 〈 0.05 ）. The degree of ametropia also had a certain influence on corneal cutting errors. In SBK group and Fem- LASIK group, the higher of myopia degree was, the bigger cutting errors became, and there was a statistical significant correlation （ Both P 〈 0. 01 ）. Preoperative corneal thickness almost had no influence on corneal cutting errors （ All P 〉 0.05 ）. Conclusion Surgery type is the main factor that influences cutting errors of central cornea in la- ser-assisted refractive surgeries. Among all 5 types of surgery, SMILE is significantly su- perior to the others.