SMILE术后角膜后表面形态变化临床研究

目的:研究飞秒激光小切口角膜基质透镜取出术(SMILE)后角膜后表面形态的变化。方法:对120例240眼施行SMILE手术的患者进行回顾性病例研究。按术前等效球镜将其分为轻度近视组(≤-3.00D)、中度近视组(>-3.00~<-6.00D)及高度近视组(≥-6.00D)。分别于术前,术后1d,1wk,1、3、6、12mo进行Pentacam三维眼前节分析系统检测,比较角膜顶点后表面高度和直径2、6mm同心圆上角膜后表面高度的变化趋势。结果:三组角膜顶点,2mm环角膜后表面高度在术后不同时间点时间、组间有差异(顶点:F时间=30.09,P时间<0.01;F组间=7.29,P组间<0.01;2mm环:F时间=24.72,P时间<0.01;F组间=7.44,P组间=0.01),而组间×时间无差异(顶点:F时间×组间=1.65,P时间×组间=0.15;2mm环:F时间×组间=1.81,P时间×组间=0.25)。6mm环角膜后表面高度在术后不同时间点比较,时间有差异(F时间=18.34,P时间<0.01),而组间及组间×时间无差异(F组间=2.21,P组间=0.12;F时间×组间=1.34,P时间×组间=0.25)。轻、中度近视组顶点、2mm环、6mm环在术后1mo内角膜后表面高度变化均有差异(P<0.05)。高度近视组顶点、2mm环在术后3mo内角膜后表面高度变化均有差异(P<0.05);6mm环在术后1mo内有差异(P<0.05)。三组角膜顶点与2mm环术后1wk与术后1d角膜后表面高度差值均为负,之后差值变正且值变小。6mm环术后1wk与术后1d差值为正,之后差值变负且值变小。结论:不同近视组患者SMILE术后角膜后表面变化一致,角膜中央区域均轻度后移,周边区域均轻度前移,术后1wk达到最大值,之后均趋于向术前状态缓慢恢复。手术的稳定性、精确性、安全性、可预测性好。

Clinical research of changes in posterior corneal elevation after small incision lenticule extraction

AIM:To assess the changes of posterior corneal elevation after small incision lenticule extraction(SMILE).

METHODS:A retrospective study was conducted on 120 patients(240 eyes)who underwent SMILE surgery with myopia. All patients were examined with the Pentacam of preoperation and 1d, 1wk, 1, 3, 6 and 12mo postoperatively, respectively. We analyze the change of the posterior corneal elevation of the apex, and the change of mean posterior corneal elevation in the circle of 2mm, and 6mm diameter.

RESULTS:Comparison among the three groups showed that the differences of apex and 2mm circle at a different time and between the groups were statistically significant(apex: F_time=30.09, P_time<0.01; F_group=7.29, P_group<0.01; 2mm circle: F_time=24.72, P_time<0.01; F_group=7.44, P_group=0.01), and there was no statistically significant difference in interaction time and groups(apex: F_time×group=1.65, P_time×group=0.15; 2mm circle: F_time×group=1.81, P_time×group=0.25). The difference of 6mm circle at different time points after the operation was statistically significant(F_time=18.34, P_time<0.01), while the difference in interaction time and groups was not statistically significant(F_group=2.21, P_group=0.12; F_time×group=1.34, P_time×group=0.25). In the low and moderate myopia groups, the changes of the apex, 2mm circle and 6mm circle in the posterior corneal elevation were statistically significant within 1mo after surgery(P<0.05); In the high myopia group, there were statistically significant at the apex and 2mm circle within 3mo after surgery(P<0.05); There was statistically significant after surgery at 6mm circle within 1mo(P<0.05). In all cases, the difference of the posterior corneal elevation between 1wk and 1d was negative at the apex and 2mm circle, after that, the difference became positive and smaller. The reverse was true at the 6mm circle.

CONCLUSION:Among three groups after SMILE, the central posterior cornea was slightly backward, and the peripheral cornea was slightly forward, the changes were most obvious after 1wk and then returned gradually. It means the surgery was safe, stable, precise, and predictable.