Moria OUP-SBK和Schwind C.P角膜板层刀制作LASIK角膜瓣的形态比较

A comparison of corneal flap structure after LASIK with Moria OUP-SBK and Schwind C.P. microkeratome

目的 对角膜板层刀Moria OUP-SBK和Schwind C.P.制作LASIK角膜瓣的规则性、稳定性及精确性进行比较,为临床选用角膜板层刀提供理论依据.方法 前瞻性病例对照研究.对准备接受准分子激光原位角膜磨镶术（LASIK）矫正近视及散光的44例患者按照使用的机械角膜刀不同分成SBK组（使用Moria OUP-SBK角膜刀,24例48眼,预期制瓣厚度100 μm）和CP组（使用Schwind C.P.角膜刀,20例40眼,预期制瓣厚度110 μm）.于术后1周及1个月用Visante眼前节光学相干断层扫描仪测量患者角膜瓣水平径上共7个点的厚度（角膜顶点及水平方向鼻、颞侧距顶点1.0、2.0、3.0 mm处）.对各测量点角膜瓣厚度（MFT）值进行单因素方差分析以比较两组制瓣的规则性；分别对两组间各测量点MFT值的标准差（SD）绝对值进行比较,以比较制瓣的稳定性；对两组间角膜瓣各点平均厚度偏差（MD）的绝对值进行独立样本t检验,以比较两种角膜板层刀制瓣的精确性.结果 术后1周及1个月,SBK组角膜瓣各测量点厚度差异无统计学意义；CP组差异有统计学意义（F=17.754、15.242,P＜0.01）,但关于角膜顶点对称的鼻侧、颞侧测量点间厚度差异无统计学意义.术后1周,SBK组各点MFT值间最大差值为2.9 μm（100.4～103.3 μm）,SD均值为7.9 μm；CP组最大差值为18.4 μm（105.5～123.9 μm）,SD均值为9.7 μm.术后1个月SBK组各点MFT值间最大差值为2.9 μm（101.2～104.1 μm）,SD均值为8.2 μm;CP组最大差值为17.7 μm（106.5～124.2 μm）,SD均值为9.9 μm.两组间角膜瓣各点MD值中只有术后1周距角膜顶点鼻侧及颞侧1.0 mm及术后1个月距角膜顶点颞侧1 mm处差异无统计学意义.结论 总体上,Moria OUP-SBK制瓣的规则性、稳定性及精确性均优于Schwind C.P.板层刀,但在接近角膜中央区2 mm范围内,两者规则性及稳定性相当,且后者所制角膜瓣厚度在水平方向上关于角膜顶点是对称的.

Objective To compare the consistency, stability and accuracy of corneál flaps created by either Moria OUP-SBK or Schwind C.P.microkeratome after laser in situ keratomileusis （LASIK）.Methods A total of 44 patients （88 eyes） in this prospective study who underwent LASIK were divided into two groups according to the microkeratome used in surgery： group SBK （with Moria OUP-SBK head 100 μm,48 eyes） and group CP （with Schwind C.P.head 110 μm,40 eyes）.The flap thickness of each patient was measured at 7 points for each horizontal image （vertex and 1.0 mm,2.0 mm, 3.0 mm temporally and nasally to the vertex） 1 week and 1 month postoperatively using Visante anterior segment optical coherence tomography.The mean flap thickness （MFT） at different measuring points was compared using a one-way ANOVA for analysis in each group 1 week and 1 month after LASIK.The standard deviations （SD） of each measuring point＇s thickness was compared by analyzing the stability in making corneal flaps for the two groups.Moreover,the mean deviation （MD） of corneal thickness for the two groups was compared using an independent samples t test 1 week and 1 month postoperatively.Results There was no difference in MFT between the different points in group SBK,while it was dramatically different in group CP 1 week （F=17.754,P〈0.01） and 1 month （F=15.242, P〈0.01） after LASIK.The maximum differences of the MFT at different measuring points 1 week and 1 month postoperatively were both 2.9 μm in group SBK and were 18.4 μm and 17.7 μm in group CP.The average of the standard deviation （SD） of the MFT in group SBK was 7.9 μm and 8.2 μm 1 week and 1 month postoperatively,respectively,while it was 9.7 μm and 9.9 μm in group CP.And finally,only the points 1 mm to the horizontal vertex 1 week after LASIK and the point 1 mm temporally to the vertex 1 month after LASIK showed no statistical differences in MD between the two groups.Conclusion Both microkeratomes are stable in making corneal flaps,and the Moria OUP-SBK is more consistent and accurate than the Schwind C.P.