Sirius角膜地形图仪测量LASIK和LASEK术后角膜后表面的研究

目的通过Sirius角膜地形图仪测量LASIK和LASEK术后角膜后表面，分析其变化特点．评价各因素对角膜后表面变化的影响。方法前瞻性临床研究。人选2012年5月至2013年7月在宁波第一医院行准分子激光屈光手术患者，其中LASIK手术37例（74眼），LASEK手术26例（52眼），术前应用Sirius角膜地形图仪测量每眼．并完善术前常规检查，记录相关数值。记录患者术中的切削深度、切削比例、残留基质厚度，术后1周、1个月、3个月复查。各时间点之间数据比较应用重复测量资料方差分析．各变量与角膜后表面高度变化量之间的影响程度应用多元线性回归。结果LASIK与LASEK术后1周、1个月和3个月角膜后表面高度与术前比较稍增高，差异有统计学意义（F=43.58、7.51，P〈0.01）；残留基质对LASIK术后1周、1个月和3个月后表面高度变化量有影响（f=-3.421、-3.376、-3.116，P〈0.01），对LASEK术后1个月和3个月后表面高度变化量有影响（t=-3.077、-2.872，P〈0.01）。结论Sirius角膜地形图仪测定显示LASIK、LASEK术后均表现为角膜后表面微量前移。残留基质厚度对角膜后表面变化影响较大。

An analysis of changes in the posterior corneal surface using Sirius topography after LASIK and LASEK

Objective To discuss the relationship between changes m the posterior corneal surface and refractive surgery using Sirius 3D topography; to further analyze and evaluate factors that affect the posterior corneal surface. Methods This was a prospective clinical study. Myopic patients who underwent excimer laser refractive surgery from May 2012 to July 2013 in Ningbo First Hospital were chosen （74 eyes of 37 LASIK patients and 52 eyes of 26 LASEK patients）. Sirius 3D topography was used to reveal the corneal topography of the posterior corneal surfaces preoperatively. Ablation depth （AD）, ablation ratio （ablation depth/corneal thickness, AD/CT） and residual bed thickness （RBT） were recorded for every patient during surgery and again at 1 week, 1 month and 3 months postoperatively. Data were compared by repeated measured ANOVA, multiple linear regression was used to reveal the relationship between the related factors and the changes in the posterior corneal surface. Results The posterior corneal surface had a slightly forward shift after refractive surgery. There were significant differences in posterior surface elevation before and after LASIK and LASEK at 1 week, 1 month and 3 months （F=43.58, 7.51, P〈0.01）. RBT was correlated with the posterior corneal surface variations at 1 week, 1 month, and 3 months after LASIK （t=-3.421, -3.376, -3.116; P〈0.01） and 1 month and 3 months after LASEK （t=-3.077, -2.872; P〈0.01）. Conclusion Sirius 3D topography measurements show that the corneal posterior surface has a slightly forward shift in both LASIK and LASEK. RBT has a strong influence on corneal posterior surface variation.