不同大小切口飞秒激光基质透镜切除术矫正近视术后角膜地形图对比研究

Effects of different incision sizes on corneal topography changes after femtosecond lenticule extraction surgery for myopia

目的探讨飞秒激光基质透镜切除术中采用不同大小切口对术后角膜地形图参数变化的影响。方法将80例(160眼)行飞秒激光基质透镜切除术的近视患者按切口大小分为3组,A组(切口弧长19.0 mm)50眼,B组(切口弧长5.0 mm)50眼,C组(切口弧长2.5 mm)60眼。术后随访6个月,记录术前最佳矫正视力、术后裸眼视力、裂隙灯显微镜及Orbscan-Ⅱ检查模拟角膜镜读数(Sim K值)、后表面Diff值、3 mm Irreg值、5 mm Irreg值,并对结果进行分析。结果术后1周、1个月、3个月、6个月裸眼视力3组相比,差异均无统计学意义(均为P>0.05)。术后6个月3组Sim K差值均较术前减少,差异均有统计学意义(均为P<0.05),但术后3组间Sim K差值相比较,差异无统计学意义(P>0.05)。术后6个月3组角膜3 mm Irreg值、5 mm Irreg值均较术前显著增加,差异均有统计学意义(均为P<0.05);术后6个月3 mm Irreg值、5 mm Irreg值C组<B组<A组,但仅5 mm Irreg值C组与A组相比差异有统计学意义(P=0.024)。3组术后后表面Diff值与术前相比均显著增加(均为P<0.05),术后6个月后表面Diff值增加量(后表面前凸)C组<B组<A组,但差异无统计学意义(P>0.05)。结论微小切口的飞秒激光基质透镜切除术在术后角膜散光、角膜规则性和角膜后表面前凸方面都显示出较好的效果。

Objective To evaluate the effects of different incision sizes on the changes of corneal topography after femtosecond laser lenticule extraction for myopia. Methods A total of 80 patients （ 160 eyes） underwent femtosecond laser lenticule extraction were divided into three groups according to incision sizes： Group A （ incision size 19.0 ram,50 eyes） ,group B （incision size 5.0 mm,50 eyes） ,group C （incision size 2.5 mm, 60 eyes）. The best corrected visual acuity （BCVA）, uncorrected visual acuity （UCVA）, diopter, intraocular pressure and corneal topography were performed before operation and 1 day, 1 week, 1 month, 3 months, and 6 months after operation. Simulated keratoscopy reading （SimK）, difference quantity （Diff）, 3 nun irregular quantity （Irreg） and 5 nun Irreg were recorded and analyzed. Results Compared with before operation,UCVA of three groups had no significantly difference at postoperative 1 week, 1 month,3 months and 6 months （ all P 〉0.05 ）. In all patients, SimK difference value decreased significantly after the operation （ all P 〈 0.05 ）, but that of three groups showedno significant difference （P 〉 0.05 ）. The postoperative 3 mm Irreg and 5 mm Irreg of each group were significantly higher than before operation（ all P 〈 0.05 ）. After 6 months of operation, 3 mm Irreg and 5 mm Irreg of group C were lower than those in group A and group B, but the difference only in 5 mm Irreg between group C and A had statistical significant （P = 0. 024）. Postoperative posterior corneal surface Diff value of each group were much higher than preoperative ones （ all P 〈 0. 05）. At postoperative 6 months,posterior corneal surface Diff value increased amount of group C and B were lower than those of group A, but the difference was not statistically significant （P 〉 0. 05 ）. Conclusion Small incision lenticule extraction show good effects in postoperative corneal astigmatism, corneal regularity and posterior corneal surface ectasia.