飞秒LASIK与SBK术后角膜像差的对比分析

目的 比较飞秒激光FS200制瓣辅助的LASIK（FS-LASIK）和角膜板层刀制瓣的前弹力层下激光角膜磨镶术（SBK）的临床效果及角膜像差变化.方法 前瞻性病例对照研究.34例（68眼）应用FS200飞秒激光制瓣（FS组）患者和45例（90眼）M2微型角膜板层刀制瓣（SBK组）患者纳入研究.术前及术后1、3个月分别检查记录2组患者的裸眼视力、屈光度、矫正视力,并采用Pentacam-HR眼前节分析系统,对术眼进行眼前节扫描获得三维图像,通过内置分析软件获取瞳孔直径为6 mm的角膜总高阶像差（HOA）、球差（C40）、水平彗差（C31）、垂直彗差（C3-1）和水平三叶草（C33）、斜向三叶草（C3-3）数据,采用方差分析及t检验进行统计分析.结果 FS组角膜HOA、C40、C3-1手术前后比较差异均有统计学意义（F=8.511、12.356、11.843,P＜0.01）;SBK组角膜HOA、C40、C3-1、C31差异也存在统计学意义（F=46.601、38.627、10.874、11.727,P＜0.01）.术后1个月时SBK组HOA的增高幅度明显高于FS组,差异有统计学意义（t=3.063,P＜0.05）,术后3个月仍有同样趋势（t=2.998,P＜0.05）.术后1个月时2组患者角膜球差均有增高,组间差异无统计学意义（t=-1.990,P＞0.05）,而3个月时FS组有所恢复,组间差异有统计学意义（t=-2.666,P＜0.05）.2组三叶草像差（C33、C33）均较术前增加,术后1、3个月斜向三叶草（C3-3）与术前比较差异有统计学意义,但组间比较差异无统计学意义.结论 FS-LASIK和SBK均可造成角膜总高阶像差、球差、垂直彗差的增加,但FS-LASIK角膜总高阶像差和球差的增幅比SBK小,在提高视觉质量方面飞秒可发挥更大的作用.

Comparison of corneal aberrations after femtosecond laser LASIK and SBK

Objective To compare changes in wavefront aberrations on the cornea after femtosecond laser LASIK （FS-LASIK） and sub-Bowman＆#39;s keratomileusis （SBK）,especially for total higher order aberrations （HOA）,corneal spherical aberrations （C40）,corneal horizontal coma （C31）,corneal vertical coma （C3-1）,corneal horizontal trefoil （C33） and corneal oblique trefoil （C3-3）.Methods A prospective study was designed for 2 groups based on the procedure used.The groups were composed of 68 eyes of 34 patients who had undergone FS-LASIK and 90 eyes of 45 patients who had been treated with SBK.A Pentacam was used under dark room conditions to measure corneal aberrations before surgery and 1 and 3 months after surgery.Data were analyzed using ANOVA,an independent samples t test and Pearson correlation.Results The preoperative and postoperative differences for the total corneal HOA,corneal C40,and corneal C31in the FS-LASIK group were significant （F=8.511,12.356,11.843,P〈0.01）.The corresponding differences and in addition corneal C31 were also significant for the SBK group （F=46.601,38.627,10.874,11.727,P〈0.01）.One month after surgery,HOAs were higher in the SBK group than in the FS group （t=-3.063,P〈0.05）,and the same tendency was found 3 months after surgery （t=2.998,P〈0.05）.The differences for C40 at 1 month were not significant between the two groups （t=-1.990,P〉0.05） but the differences were statistically significant at 3 months （t=-2.666,P〈0.05）.One and 3 months after surgery,the trefoil aberrations （C33,C3-3） of the cornea in the two groups were higher than before surgery; only the difference for C3-3 was significant.However,the difference in the trefoil aberrations of the cornea between the two groups was not statistically significant.Conclusion Both FS-LASIK and SBK can increase corneal HOA,corneal spherical aberrations and vertical coma,but the degree of increase after FS-LASIK is smaller than that after SBK.FS-LASIK improves visual quality more than SBK.