消像差设计飞秒LASIK手术后角膜高阶像差的观察

目的观察消像差设计飞秒LASIK手术后角膜高阶像差的变化。方法 分析74例患者146眼的临床资料,在术前和术后进行标准检查测量角膜像差。应用Custom Ablation Manager软件进行消像差手术设计,应用SCHWIND AMARIS准分子激光仪进行激光切削,应用Intralase飞秒激光制作角膜瓣。术后3个月测量高阶像差(higher order aberrations, HOAs)的改变。 结果 术后除三叶草差外,其余各角膜高阶像差指标均较术前增大,差异有统计学意义(t=13.03、12.35、8.25、5.26,P<0.01)。切削区较小时,矫正单位屈光度引起的HO-RMS增加量、球差增加量和彗差增加量高于切削区较大时,差异有统计学意义(F=17.86、36.76、2.97,P<0.05)。预矫屈光度数高的组,矫正单位屈光度引起的HO-RMS增加量、球差增加量和彗差增加量均高于预矫屈光度数低的组,差异有统计学意义(t=5.54、5.24、2.80,P<0.01)。结论 消像差设计飞秒LASIK手术后,角膜高阶像差较术前增加。矫正的屈光度数越高,术后角膜高阶像差增加越多；切削区越小,术后角膜高阶像差增加越多。

Analysis of corneal higher-order aberrations after femtosecond LASIK with aberration-free profiles

Objective To investigate the changes of higher-order aberrations(HOAs)in eyes after femto-LASIK operation using an aberration-free ablation profile. Methods Seventy four patients (146 eyes) were included in the study. Standard examinations, preoperative and postoperative analysis with corneal wavefront topography were performed. Aberration-free aspheric treatments were designed using the Custom Ablation Manager software and ablations were performed by the SCHWIND AMARIS excimer laser system. The corneal flaps were created using Intralase femtosecond laser system. The changes in higher order aberrations(HOAs) from preoperative to 3 months postoperative were evaluated. Results The postoperative values of corneal HOAs were increased except trefoil(t=13.03,12.35,8.25,5.62, P<0.01). Compared with the lager optical zone, every diopter correction with the smaller optical zone was resulted in significant higher increments of HO-RMS, spherical aberration and coma(F=17.86,26.76,2.97, P<0.05). The higher attempted spherical equivalent induced the higher values of HO-RMS/D, spherical aberration/D and coma/D. The differences of the values between the higher and lower attempted spherical equivalent were statistically significant(t=5.54,5.24,2.80, P<0.01). Conclusion Corneal HOAs are increased after femtosecond LASIK using aberration-free profiles. The higher level of attempted spherical equivalent and smaller optical zone may induce more corneal HOAs.