IntraLase FS60和Femto LDV飞秒激光制作角膜瓣的特点

Characteristics of flaps created with an IntraLase FS60 femtosecond laser versus a Femto LDV femtosecond laser

目的 探讨应用IntraLase FS60飞秒激光和Femto LDV飞秒激光制作的准分子激光原位角膜蘑镶术（LASIK）角膜瓣的特点.方法 前瞻性对照研究.拟行LASIK手术的近视患者60例（120眼）,根据角膜瓣制作方法不同分为两组,IntraLase FS60飞秒激光和Femto LDV飞秒激光组,每组各30例（60眼）.两组均制作预计110 μm厚度的角膜瓣.术前所有患者均进行常规检查并记录相关资料,包括年龄、屈光度、角膜曲率、角膜厚度等.术后1周,应用眼前节光学相干断层扫描仪（Visante OCT）分别测量每个角膜上0°、45°、90°和135°四条经线所在截面上特定5个点的角膜瓣厚度,并对每个角膜瓣上20个测量点的瓣厚度进行对比分析.采用独立样本t检验、单因素方差分析对相关数据进行统计学处理,分析角膜瓣的重现性、规整性和精确性.结果 角膜瓣重现性：术后1周,IntraLase FS60组和Femto LDV组中央区角膜瓣厚度均值分别为（111.2±3.3）μm和（108.1±3.0）μm,全角膜瓣厚度为（110.8±2.3）μm和（109.0±2.2）μm,变异范围为（22.0±6.6）μm和（23.7±5.8）μm,两组差异均无统计学意义（P均＞0.05）.角膜瓣均一性和规整性：两组角膜瓣厚度的均值均匀分散在预计值110 μm周围,差异均无统计学意义.IntraLase FS60组中央、旁中央、周边区域的角膜瓣厚度差异无统计学意义（F=1.213,P=0.300）;Femto LDV组中央和周边区域角膜瓣厚度差异存在统计学意义（F=3.925,P=0.021）,其他区域角膜瓣厚度差异无统计学意义.两组中各自双眼鼻侧和颞侧角膜瓣厚度对比,组间差异均无统计学意义.角膜上四条经线所在截面的平均角膜瓣厚度差异也无明显统计学意义.角膜瓣精确性：角膜上每个对应点的角膜瓣厚度与预计值110 μm差值的最大均值,IntraLase FS60组为6.2μm,Femto LDV组为6.7 μm.两组中与预计值差值≤5 μm的测量点,IntraLase FS60组有694个（占57.83%）,Femto LDV组有646个（占53.83%）,差异无统计学意义.结论 应用飞秒激光制作LASIK角膜瓣,具有较好的重现性和较高的精确性,角膜瓣形态均一、规整.IntraLase FS60飞秒激光和Femto LDV飞秒激光制作的角膜瓣形态特点相似.

Objective To compare the features of the laser in situ keratomileusis （LASIK）flaps created with the IntraLase FS60 femtosecond laser versus the Femto LDV femtosecond laser.Methods One hundred and twenty eyes of 60 consecutive patients were enrolled in this prospective study and divided into 2 groups depending on the flap creation method： the lntraLase FS60 group （60 eyes） and the Femto LDV group （60 eyes）. The expected flap thickness was 110 μm for both groups. Preoperative all patients were routine inspected and recorded relevant information, including age, diopter, corneal curvature and corneal thickness, etc. Anterior segment optical coherence tomography was used to measure the flap thicknesses of the 5 specified measurements in the 0°,45°, 90° and 135° meridians on the corneas, at one week postoperatively. Independent samples t test and single factor analysis of variance were used for data statistics processing. Results At one week after surgery, the central flap thicknesses were （111.2±3.3）μm and （108.1±3.0）μm, respectively;the whole flap thickness were （110.8±2.3）μm and （109.0±2.2）μm, respectively; the rang of variations were （22.0±6.6）μm and （23.7±5.8）μm, respectively, in the IntraLase FS60 group and Femto LDV group. Both groups were not statistically different （P〉0.05 for all）. The average thickness values in the central, paracentral and peripheral zones were not significantly different in the IntraLase FS60 group （F=1.213, P=0.300）; while the central zone was significantly thinner than the peripheral zones in the Femto LDV group （F=3.925, P=0.021）. In the two groups, the nasal and temporal flap thicknesses were not significantly different and the means of the flap thickness in the four meridians were similar. The maximum deviation from the intended flap thickness （110 μm） was 6.2 μm in the IntraLase FS60 group; while the maximum deviation was 6.7 μm in the Femto LDV group. The difference was less than 5 μm was 57.83% （694/1200） in the IntraLase FS60 group, 53.83% （646/1200）in the Femto LDV group. Conclusion Femtosecond laser flaps are accurate and have good repeatability. The architecture of flaps are uniform and regular. The characteristics of LASIK flaps created with the IntraLase FS60 femtosecond laser versus the Femto LDV femtosecond laser are similar.