VisuMax飞秒激光准分子激光原位角膜磨镶术娇正高度近视术后角膜前后表面高阶像差变化

目的 探讨VisuMax飞秒激光准分子激光原位角膜磨镶术(LASIK)矫正高度近视术后角膜前后表面高阶像差的变化情况.方法 前瞻性连续病例研究.选择行LASIK矫正高度近视(等效球镜度数-6.38～-13.50 D)患者22例((41眼),其中使用Visumax飞秒激光制瓣11例(21眼),Moria M3旋转式微型角膜刀制瓣11例(20眼).采用Pentacam-HR眼前节分析系统,分别在术前、术后6个月对术眼进行眼前节三维图像采集,记录基于角膜前后表面高度图获取的分析直径为6 mm的角膜前后表面高阶像差均方根值及各阶像差的Zernike系数,计算彗差和初级球差,采用方差分析及t检验进行统计分析.结果 术后飞秒激光组和角膜刀组的角膜前表面总高阶像差均方根值、彗差、初级球差均较术前显著增加(P<0.05),其中角膜刀组的彗差增加量显著高于飞秒激光组[分别为(0.788±0.592)μm及(0.403±0.572)μm,P<0.05];术后飞秒激光组的角膜后表面总高阶像差均方根值、彗差、初级球差的绝对值均较术前增加(P<0.05),而角膜刀组的角膜后表面像差在手术前后差异无统计学意义(P>0.05);与角膜刀组相比,飞秒激光组术后角膜后表面的彗差增加量更显著[分别为(0.004±0.031)μm及(0.027土0.036)μm,P<0.05].结论 VisuMax飞秒激光LASIK矫正高度近视比角膜刀制瓣引起的角膜前表面彗差增加量较少;其角膜后表面像差亦存在轻微增加,且角膜后表面彗差增加较角膜刀显著,发生机制有待进一步探讨.

Changes in anterior and posterior corneal higher order aberrations after laser in situ keratomileusis with femtosecond VisuMax for high myopia

Objective To evaluate the changes in anterior and posterior corneal higher order aberrations after laser in situ keratomileusis （LASIK） with femtosecond VisuMax for high myopia. Methods A prospective case series study was conducted. Twenty-one eyes of 11 patients underwent LASIK with flaps created by femtosecond and 20 eyes of 11 patients with flaps created by mechanical microkerarome, whose preoperative spherical equivalents were from - 6.38 to - 13. 50 diopters （D）. The three-dimensional corneal topography was obtained with Pentacam-HR system preoperatively and 6 months postoperatively. Values of root mean square （RMS） of higher order aberrations, coma and spherical aberration both in the anterior and posterior corneal surface were calculated with the pupil diameter of 6 mm. Results There were significant increases in the values of RMS, coma, spherical aberration of anterior corneal surface in both femtosecond group and mechanical microkerarome group （P 〈 0.05）. The change of coma postoperatively was more in mechanical microkerarome group than in femtosecond group [ （0. 788 ± 0. 592） μm vs （0. 403 ± 0. 572） μm, P 〈 0.05 ]. There were significant （P 〈 0.05） increases in the values of RMS, coma, spherical aberration of posterior corneal surface in femtosecond group whereas no significant difference was found in mechanical microkerarome group. The change of coma in the posterior corneal surface was more in femtosecond group than in mechanical microkerarome group [ （0.027 ± 0. 036） μm vs （0. 004 ± 0.031 ） μm,P 〈 0.05 ]. Conclusions There was more addition of coma in the anterior corneal surface induced by flap creation with mechanical microkerarome than with femtosecond VisuMax. The higher order aberrations of posterior corneal surface after LASIK with femtosecond VisuMax increased postoperatively and there were more change of coma in the posterior corneal surface after LASIK with femtosecond VisuMax than mechanical microkerarome . The mechanism of this phenomenon warrants further study.