SMILE手术矫治中高度近视术后角膜上皮重塑及其与屈光度的关系

目的 探讨飞秒激光小切口角膜微透镜取出术(small incision lenticule extraction,SMILE)矫治中高度近视术后角膜上皮厚度变化及其与术后屈光度变化的关系.方法 收集2016年1月至2017年3月接受SMILE手术的近视及近视散光患者共46例(92眼),按照屈光度分为两组,其中中度近视组29例(58眼),高度近视组17例(34眼).分别于术前、术后1个月及6个月应用傅立叶域眼前节OCT对患者角膜中央0～2 mm、角膜＞2～5 mrn、角膜＞5 ～6 mm的角膜上皮厚度进行测量,对比术后角膜上皮厚度变化特点并分析其与屈光度的相关性.结果 术前患者角膜上皮厚度为(55.68 ±3.61)μm,术后6个月角膜中央0～2 mm、角膜＞2～5 mm、角膜＞5 ～6 mm的角膜上皮厚度较术前分别增厚(3.85±3.99) μm、(3.46±3.29) μm及(2.85±3.18) μm,三个区域比较差异有统计学意义(P＜0.05).术后6个月高度近视组角膜上皮增厚较中度近视组更明显,且差异有统计学意义(P=-0.047).术后6个月,两组角膜中央2 mm上皮厚度变化与术后屈光度变化均未发现显著相关性(中度组:r=0.219,P=0.633;高度组:r=0.197,P=0.585).结论 SMILE术后角膜上皮发生重塑,主要表现为角膜上皮厚度的增厚,屈光度越高,增厚越显著,这种重塑效应未对术后屈光度稳定性造成影响.

Corneal epithelial remodeling and its relationship with diopter after SMILE for moderate and high myopia

Objective To evaluate the changes in epithelial thickness profile and its relationship with diopter following small incision lenticule extraction (SMILE) for moderate and high myopia.Methods Together 46 myopia or myopic astigmatism (92 eyes) who underwent SMILE were included under the informed consent from January 2016 to March 2017 and were decided into 2 groups according to the diopter:moderate myopia group (58 eyes)and high myopia group (34 eyes).Epithelial thickness profile was measured using spectral-domain optical coherence tomography at different corneal zones (0-2 mm,＞ 2-5 mm and ＞ 5-6 mm cornea) preoperatively before surgery and 1 month and 6 months after surgery for observing the changes in epithelial thickness and its correction with diopter.Results The mean epithelial thickness in the central zone was (55.68 ± 3.61) μm before surgery,and,6 months after surgery,it was thickened by (3.85-±3.99),(3.46 ±3.29) and (2.85 ±3.18) μm in the 0-2 mm,＞2-5 mum and ＞5-6 mm cornea respectively,and the difference was statistically significant among the three zones (P ＜ 0.01).After surgery for 6 months,the epithelial thickness in the high myopia group was thickened more obviously compared with the moderate myopia group (t =1.440,P =-0.047).And no correlation was found between changes in the epithelial thickness at 0-2 mm cornea and diopter after surgery(moderate myopia group:r =0.219,P=0.633;high myopia group:r =0.197,P =0.585).Conclusion Significant epithelial thickening was observed after SMILE,presenting the thickened epithelium.The higher the diopter was,the more thickened the epithelium was.The epithelial changes does not appear to affect the diopter after SMILE.