中文摘要：

目的：评估和对比飞秒激光小切口角膜基质透镜取出术（SMILE）和飞秒激光制瓣的准分子激光原位角膜磨镶术（FS-LASIK）角膜前表面非球面性的变化特点。方法病例对照研究。收集自愿选择行SMILE手术的屈光不正患者45例作为试验组，另收集行FS-LASIK的屈光不正患者33例作为对照组。均选右眼为研究眼，于术前、术后1周及1、3、6个月分别测量患者角膜前表面6、7、8、9 mm直径范围下的非球面系数Q值，对两组间的Q值变化特点进行对比分析。分析Q值变化量与中央切削深度（CCD）的相关关系。两组间一般资料及术前Q值的比较采用独立样本t检验，Q值整体分析采用方差分析。结果术后1周时角膜前表面Q值，SMILE组分别为：0.85±0.31、0.80±0.28、0.69±0.25、0.51±0.23；FS-LASIK组分别为：1.13±0.56、1.01±0.47、0.80±0.39、0.51±0.31。各直径范围下手术前后不同时间所测Q值差异均有统计学意义（P〈0.05），且手术方式与时间之间均存在交互效应；其中6和7mm直径时不同手术方式间差异也有统计学意义（P〈0.05）。两组间术后1周与术前的Q值差值（ΔQ）在6、7mm直径范围下差异有统计学意义（P6mm=0.004，P7mm=0.014）。SMILE组帽直径较FS-LASIK组小；CCD较FS-LASIK组大。各直径范围下ΔQ与帽/瓣直径均无线性关系。各直径范围下ΔQ与CCD均呈线性关系（P〈0.05），且FS-LASIK组相关程度优于SMILE组。结论 SMILE与FS-LASIK均会使角膜前表面的Q值由负变正。然而，SMILE对角膜前表面非球面性的影响较FS-LASIK小。（中华眼科杂志，2016，52：681-685）

英文摘要：

Objective To evaluate and compare the anterior corneal asphericity after small incision lenticule extraction （SMILE） and femtosecond laser in situ keratomileusis （FS-LASIK） . Methods In this case-control study, 45 subjects who underwent SMILE operation comprised the study group, and 33 subjects with FS-LASIK operation comprised the control group. The asphericity coefficient Q-value of the right eyes in both groups was measured at diameters of 6, 7, 8 and 9 mm, respectively, before surgery and at 1 day, 1 week, 1 month and 6 months following surgery. The correlation between the variation of Q-value and the central cutting depth was analyzed. Results The Q-value of anterior corneal surface was 0.85 ± 0.31, 0.80 ± 0.28, 0.69 ± 0.25 and 0.51 ± 0.23 after SMILE, and 1.13 ± 0.56, 1.01 ± 0.47, 0.80 ± 0.39 and 0.51 ± 0.31 after FS-LASIK at 1 week. In both groups, the Q-value was significantly different before and after surgery（P〈0.05）;there were interaction effects between the operation method and time;the difference between the two groups at 6-mm and 7-mm diameters was statistically significant （P〈0.05）. The variation of the Q-value before and after operation（ΔQ）showed significant difference（P6mm=0.004,P7mm=0.014）between the two groups at 6-mm and 7-mm diameters. The cap diameter of the SMILE group was smaller than that of the FS-LASIK group, but the cutting depth was larger. There was no correlation between ΔQ and the cap/disc diameter. It showed a linear relationship（P〈0.05）betweenΔQ and the central cutting depth at all examined diameters in the two groups, and the relation degree in the FS-LASIK group was superior to the SMILE group. Conclusions Both SMILE and FS-LASIK operations can change the negative Q-value of the anterior corneal surface to the positive. The impact of SMILE on the asphericity is smaller than that of FS-LASIK.