LASIK和Epi-LASIK术中角膜切削误差及术后角膜地形图变化比较

Keratectomy errors and changes in corneal topography after LASIK and Epi-LASIK surgeries

目的探讨准分子激光原位角膜磨镶术(LASIK)和准分子激光上皮下角膜磨镶术(Epi-LASIK)术中角膜切削误差及术后角膜地形图变化。方法选取2012年2月至2014年8月我院行近视激光矫正手术患者211例(403只眼)作为研究对象,随机分为LASIK组和Epi-LASIK组,其中LASIK组110例(209只眼),Epi-LASIK组为101例(194只眼),分别采取相应手术,观察术后两组患者角膜切削误差及术前与术后1、3个月两组高度近视患者角膜地形图形态Simk差值、Simk等效值、CIM值及SF绝对值4个参数变化。结果两组中轻中度近视患者角膜切削误差无显著差异(P>0.05),Epi-LASIK组中高度近视患者的角膜切削误差显著小于LASIK组(P<0.05);两组高度近视患者术前角膜图形均以对称领结型及非对称领结型为主,两组各形态间无显著差异(P>0.05);两组高度近视患者术后角膜地形图形均以平滑型为主,LASIK组的平滑型显著低于Epi-LASIK组(P<0.05),其余形态两组比较无显著差异(P>0.05);在Simk差值、Simk等效值上,两组术后结果均显著低于术前(P<0.05),两组间术后结果对比无显著差异(P>0.05);在CIM值上,两组术后结果均显著高于术前(P<0.05),LASIK组术后结果均显著高于Epi-LASIK组(P<0.05);在SF绝对值上,两组术后结果均显著低于术前(P<0.05),两组间术后结果对比无显著差异(P>0.05)。结论 Epi-LASIK可有效降低术中角膜切削误差及改善术后角膜地形图参数,有利于增强手术的效果,促进术后患者的恢复及改善患者预后,可在临床检查中广泛推广。

Objective To examine keratectomy errors and changes in corneal topography after LASIK and EpiLASIK surgeries. Methods Authors retrospectively analyzed 211 cases of myopia laser correction surgeries performed in our hospital from February 2012 to August 2014. Patients either received LASIK or Epi-LASIK for refraction correction.Postoperative keratectomy error and changes in corneal topography parameters,including Simk difference,Simk equivalent,CIM and absolute SF were compared before and after surgery for high myopia patients. Results There were 110 patients（ 209 eyes） received LASIK and 101 patients（ 194 eyes） received Epi-LASIK respectively. There was no significant difference in keratectomy error between mild and moderate myopia patients（ P〉0. 05）. In high myopia subgroup,Epi-LASIK resulted in significantly less keratectomy error than LASIK（ P〈0. 05）. Majority of postoperative corneal topography in both groups were asymmetrical tie type before the surgery. After surgery,smooth type corneal topography was significantly higher in high myopia patients who received Epi-LASIK than in those who received LASIK（ P〈0. 05）. There was no difference in other forms of topographies between the two groups. Simk difference,Simk equivalent and absolute SF significantly reduced after surgeries in both groups（ all P〈0. 05）,and there was no difference in postoperative measurements between the two groups. CIM,in contrast,significantly increased after surgeries（ both P〈0. 05） and it was significantly higher in LASIK group than in Epi-LASIK group（ P〈0. 05）. Conclusions Epi-LASIK surgery can reduce errors,improve keratectomy corneal topography parameters,help enhance outcomes of surgery,promote postoperative recovery and improve prognosis. It can be widely promoted in the clinical examination.