方法：收集我院拟行SMILE手术的近视患者46例92眼，随机平均分为两组，A组角膜帽厚度设计为110μm，B组角膜帽厚度设计为120μm，其余手术参数设计一致，手术均由同一手术医生完成。对比两组患者术中发生不透明气泡层(opaque bubble layer，OBL)情况、透镜分离困难比率，以及术后各时间段的裸眼视力(uncorrected visual acuity，UCVA)和等效球镜度数(spherical equivalent，SE)。

结果：术中OBL发生比例两组差异有统计学意义(P<0.05)：110μm组高于120μm组； 透镜分离困难比率两组差异有统计学意义(P<0.05)：110μm组高于120μm组。术后1d和7d时120μm组UCVA较110μm组好，但随着时间的推移，术后1，3，6mo时两组UCVA相近，两组数据比较无统计学差异(P>0.05)； 且两组SE在术后7d和6mo时比较，差异无统计学意义(P>0.05)。

结论：110μm角膜帽设计较120μm设计的SMILE手术更容易出现OBL以及透镜分离困难，从而影响术后裸眼视力恢复的速度，远期裸眼视力无明显差异。

METHODS: Forty-six cases of myopia patients(92 eyes)intends to SMILE operation in our hospital were collected, and were randomly divided into 2 groups: corneal cap thickness design for 110μm in group A and 120μm in group B. Other operation parameters designs were consistent. All patients were surgeried by the same surgeon. The incidence of opaque bubble layer(OBL), the ratio of difficult separation of lens, uncorrected visual acuity(UCVA)of each time points, and spherical equivalent(SE)were compared.

RESULTS: Intraoperative OBL incidence rate of 110μm group was higher than that of 120μm group with significant difference between the two group(P<0.05). the ratio of difficult separation of lens was significantly different between the two groups: 110μm group was higher than in 120μm group(P<0.05). The UCVA in the 120μm group was better than that in the 110μm group at postoperative 1 and 7d. But with the passage of time, postoperative 1, 3, and 6mo of UCVA of 2 groups was similar, showed no significant difference(P>0.05). SE were compared at 7d and 6mo after operation, showed no significant difference(P>0.05)

CONCLUSION: Compared with 120μm group, corneal cap design SMILE operation in 110μm group are more prone to OBL and difficult separation of lens, thus affects UCVA and postoperative recovery rate. There is no significant difference in long-term UCVA.