飞秒激光LASIK角膜瓣形态及术后角膜后表面高度变化的临床研究

发布时间：2018-02-26 17:14

  本文关键词： 角膜瓣厚度 角膜后表面 高度 角膜地形图 相干光断层扫描 飞秒激光 角膜磨镶术 激光原位　出处：《天津医科大学》2012年硕士论文　论文类型：学位论文

【摘要】：目的：评价Visante Omni眼前节分析系统在测量角膜后表面的可重复性；评估飞秒激光LASIK(FS-LASIK)制作的角膜瓣的预测性、可重复性和均匀性,并与准分子激光前弹力层下角膜磨镶术(SBK)进行比较,从而了解FS-LASIK的制瓣特点；分析FS-LASIK术后早期的角膜后表面高度的变化情况,并与SBK、机械法上皮瓣下角膜镶磨术(Epi-LASIK)进行比较分析。 方法：对近视患者使用Visante Omni眼前节分析系统,采集不同区域的角膜后表面高度、8mm范围角膜后表面最平坦和最陡峭的屈光力、平均Q值,计算其组内标准差(Sw)、精度、可重复性、组内变异系数(CVw)、组内相关系数(ICC)等参数来评价Visante Omni眼前节分析系统在测量角膜后表面的可重复性；对行飞秒激光LASIK及SBK手术的患者在术后应用Visante OCT眼前节分析系统对角膜瓣厚度进行测量和获取；对行FS-LASIK手术的患者进行随访,应用Visante OMNI眼前节分析系统测量术前及术后不同时期、不同区域角膜后表面高度,并与SBK、Epi-LASIK进行对照。 结果：1.对于角膜后表面高度,组内标准差(SW)最低为0.49,最高为3.95,从顶点到周边有增加的趋势；组内变异系数(CVw)最低为0.16%,最高为2.13%；组内相关系数(ICC)均高于0.844。对于角膜后表面屈光力和非球面性(Q值)平均值,除了平坦轴的的组内标准差(SW)是6.66,其余的均小于0.1,组内变异系数(CVw)范围从0.01%到1.47%,所有的组内相关系数(ICC)均大于0.90。对三次测量的多重比较的统计学分析结果显示P值均大于0.05。在不同屈光力组,组内相关系数(ICC)值相近。2. FS-LASIK组与SBK组的平均中央角膜瓣厚度分别为(97.49±7.34) μm、(112.93±9.99)μm。FS-LASIK组实际中央角膜瓣厚度与平均中央角膜瓣厚度差值绝对值的均数为5.74±3.98μm, SBK组为8.11±5.75μm,两者相比差异有统计学意义(t=2.83,P=0.005)。角膜瓣的空间形态：FS-LASIK组在距离角膜顶点不同距离的位置,瓣厚度基本均匀一致(F=1.206,P=0.303); SBK组呈中央薄周边厚的形态,进刀部位角膜瓣厚度高于出刀部位,两者比较差异有统计学意义(t=7.246, P=0.009)。3. FS-LASIK组在角膜顶点,术前、术后1d、1周、1个月角膜后表面高度分别是2.03μm,2.26μm、2.16μm、2.06μm；在1mm、2mm区域,术后变化趋势与角膜顶点相同；在3mm区域,四个时间点角膜后表面高度分别是-4.73μm、-5.39μm、-4.73μm、-4.71μm。SBK组在角膜顶点,术前、术后1天、1周、1个月角膜后表面高度分别是1.44μm,1.74μm、1.66μm、1.53μm;在1mm、2mm区域,术后变化趋势与角膜顶点相一致；在3mm区域,四个时间点角膜后表面高度分别是-5.09μm,-5.48μm、-5.27μm、-5.19μm,术后发生了轻微的后移。Epi-LASIK组在角膜顶点,术前、术后3天、1周、1个月角膜后表面高度分别是2.47μm,1.55μm、1.55μm、2.37μm,术后发生轻微的后移；在1mm、2mm区域,与角膜顶点术后变化趋势不同,术后3天角膜后表面高度分别由术前的1.55μm、-1.87μtm变为1.92μm、0.24μm,发生轻微前移；在3mm区域,变化趋势与角膜顶点相同。统计分析表明,不同的手术方式(组间差异)及不同时间点(组内差异)的差异均无统计学意义(P0.05)。于0.05。在不同屈光力组,组内相关系数(ICC)值相近。 结论：Visante Omni眼前节分析系统在测量顶点和周边部的角膜后表面都具有相对较高的可重复性,可以用于临床对角膜后表面的评估和检测；飞秒激光制瓣与机械刀相比,在预测性和可重复方面更有优势,从中央到周边角膜瓣厚度均匀一致；FS-LASIK术后早期中央区和旁中央区的角膜后表面高度发生了微小的变化,但随时间变化逐渐恢复至术前水平,与SBK、Epi-LASIK相比无明显差异。FS-LASIK术后早期角膜后表面高度无明显变化,是一种相对安全的手术方式。
[Abstract]:Objective: To evaluate the Visante Omni system in the measurement of corneal surface repeatability; evaluation of femtosecond laser LASIK (FS-LASIK) prediction of making corneal flap, repeatability and uniformity, and excimer laser sub Bowman keratomileusis (SBK) were compared, in order to understand the characteristics of flap preparation FS-LASIK; analysis of the changes of the posterior corneal surface height early after FS-LASIK, and SBK, the mechanical method of subepithelial corneal grinding with surgery (Epi-LASIK) were compared and analyzed.
Methods: the anterior segment analysis system of myopia patients using Visante Omni, collected in different regions of the corneal surface height, 8mm range of posterior corneal surface flat and the most steep refractive power, the average Q value, calculate the group standard deviation (Sw), precision, repeatability, coefficient of variation within groups (CVw). The intraclass correlation coefficient (ICC) and other parameters to evaluate the Visante Omni system in the measurement of corneal surface repeatability; anterior segment analysis system were measured and the corneal flap thickness obtained by Visante OCT and SBK LASIK of femtosecond laser surgery in postoperative patients; the patients underwent FS-LASIK surgery were followed up the application of Visante, OMNI anterior segment analysis system in different periods were measured before and after operation, the surface height in different regions of the cornea, and SBK, Epi-LASIK were compared.
Results: 1. for the surface height of the cornea, the within group standard deviation (SW) for a minimum of 0.49, up to 3.95, the surrounding is increasing from the vertex to the group; coefficient of variation (CVw) for a minimum of 0.16%, up to 2.13%; the intraclass correlation coefficient (ICC) was higher than that of 0.844. for posterior corneal surface power and the asphericity (Q value) on average, in addition to the group of flat shaft standard deviation (SW) is 6.66, the rest of the group were less than 0.1, coefficient of variation (CVw) ranging from 0.01% to 1.47%, all the intraclass correlation coefficient (ICC) were more than 0.90. for statistical analysis of multiple comparisons three measurement results show that the P value was greater than 0.05. in different diopter groups, the intraclass correlation coefficient (ICC) values of the average central corneal flap thickness is similar to.2. FS-LASIK group and SBK group respectively (97.49 + 7.34) m, (112.93 + 9.99) m.FS-LASIK group, the actual central corneal flap thickness and the average central the vast difference between the corneal flap thickness 瀵瑰，

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