目的：比较飞秒激光小切口角膜基质透镜取出术(SMILE)中不同眼角膜帽厚度对近视散光患者术后散光及早期视觉质量的影响。

方法：采用前瞻性对照研究，选取我院2020-06/2022-06接受SMILE手术的近视散光患者54例108眼，根据随机数字表法分为A组、B组(各27例54眼)，A组、B组角膜帽厚度设计分别为110、120 μm，其余手术参数一致。比较两组患者术前及术后1 d，1 wk，1 mo的裸眼视力(UCVA)、等效球镜度(SE)、角膜硬度参数(SP-A1)、视觉质量和散光矢量分析结果等。

结果：两组患者手术前后各时间点的UCVA、SE、SP-A1有时间差异(均P<0.05)，术后1 d A组UCVA优于B组(P<0.05)。两组患者的散光矢量分析结果比较无差异(均P>0.05)。术后1 d A组的客观散射指数(OSI)低于B组，斯特列尔比(SR)高于B组(均P<0.05)。两组间术后调制传递函数截止频率(MTF cut off)、对比度视力、视觉症状及总体满意度、并发症发生率比较无差异(均P>0.05)。

结论：110 μm或120 μm的角膜帽厚度在SMILE矫正近视散光方面均是安全有效的，且不影响术后的SE、散光、SP-A1以及对比度视力。110 μm角膜帽厚度术后早期视力恢复更快且早期视觉质量优于120 μm。

METHODS: A total of 54 patients(108 eyes)with myopic astigmatism who underwent SMILE from June 2020 to June 2022 in our hospital were selected for the prospective controlled study, and patients were randomly assigned into two groups, with 27 cases(54 eyes)each. The corneal cap thickness design was 110 μm for the group A and 120 μm for the group B, while other operation parameters were consistent. Additionally, the uncorrected visual acuity(UCVA), spherical equivalent(SE), stiffness parameter A1(SP-A1), visual quality and vector parameters at baseline, 1 d,1 wk and 1 mo after surgery were compared between two groups.

RESULTS: There was a statistically significant difference in UCVA, SE, and SP-A1 between the two groups at various time points before and after surgery(all P<0.05), and UCVA in the group A was better than that in the group B at 1 d after surgery(P<0.05). There was no statistically significant difference in the results of astigmatism vector analysis between the two groups of patients(both P>0.05). The objective scattering index(OSI)of the group A was lower than that of the group B, while Strehl ratio(SR)of the group A was higher than that of the group B at 1 d after surgery(both P<0.05). There was no significant difference in modulation transfer function cutoff frequency(MTF cut off), contrast vision, visual symptoms and overall satisfaction, postoperative complications between the two groups(all P>0.05).

CONCLUSION: SMILE procedures with both 110 μm and 120 μm corneal cap thicknesses are safe and effective in correcting myopic astigmatism without affecting postoperative SE, astigmatism, SP-A1 or contrast visual acuity. Whereas 110 μm corneal cap thickness results in faster early postoperative visual recovery and better early visual quality than 120 μm.