方法：纳入2020-05/2020-09在江苏省人民医院接受SMILE手术的近视患者。根据患眼屈光状态分为低、中、高度近视组。术前，术后1、3mo用Pentacam眼前段分析系统测量CCT。在不同的近视组中，每次随访期间同时计算角膜中央切削误差(ΔCCT，定义为实际CCT和预测CCT之间的差值)。分析ΔCCT的差值比以及ΔCCT、CCT与切削光学区直径的关系。

结果：研究共纳入患者221例432眼。术后3mo，高度近视组的ΔCCT大于中、低度近视组(χ²=225.74，62.55， 均P<0.01)，中度近视组大于低度近视组(χ²=132.77， P<0.01)。在术后1、3mo，三组之间的切削偏差率也有显著差异。Pearson相关分析发现术前屈光力、光学区直径与术后3mo ΔCCT之间存在线性回归关系(r=0.699， P<0.001； r=0.572， P<0.001)。

结论：SMILE手术的ΔCCT随着近视度数的增加而增加，且ΔCCT与术前等效球镜度数和光学区直径呈正相关。

METHODS: Myopic patients who had undergone SMILE surgery from May 2020 to September 2020 at the Jiangsu Province Hospital were included in the study. Data were organized by refractive status into low, moderate, and high myopia groups. The CCT was measured by the Pentacam anterior segment analysis system preoperatively and postoperatively at 1 and 3mo. Among different myopia groups, the cutting error(ΔCCT, defined as the difference between actual CCT and the predicted CCT)was calculated simultaneously during each visit. The difference ratio of ΔCCT and the relationship between ΔCCT, CCT, and cutting diameter were analyzed.

RESULTS: There were 221 patients(432 eyes)included in our study. At 3mo after operation, the ΔCCT in the high myopia group was larger than the low and moderate myopia group(χ²=225.74, 62.55; all P<0.01), and the moderate myopia group was larger than the low myopia group(χ²=132.77, P<0.01). The cutting deviation rate was also significantly different among three groups at 1 and 3mo after surgery. Pearson correlation analysis found that there was a linear regression relationship among preoperative refractive power, optical zone diameter and the central corneal cutting error at 3mo after operation(r=0.699, P<0.001; r=0.572, P<0.001).

CONCLUSION: The ΔCCT after SMILE increased with the increased of myopia, and the cutting error was positively correlated with preoperative equivalent spherical power and optical zone diameter.