不同激光角膜屈光术后角膜光密度的对比分析

目的　探讨高度近视患者行飞秒激光小切口角膜基质透镜取出术(SMILE) 、飞秒激光制瓣的准分子激光原位角膜磨镶术(FS-LASIK)以及准分子激光上皮瓣下角膜磨镶术(LASEK)术后不同时间不同直径范围内角膜光密度的对比及变化情况，及其与术中切削深度、切削厚度的相关性分析。方法　前瞻性队列研究。收集在青岛大学附属医院眼科就诊并进行屈光手术矫正的高度近视患者82例（164眼），按手术方式分为SMILE组30例（60眼）；FS-LASIK组27例（54眼）；LASEK组25例（50眼），于术前、术后1个月、术后3个月、术后6个月以及术后12个月行Pentacam三维眼前节分析系统检查，采用SPSS 22.0统计软件对术后同一时间不同术式角膜0～6 mm、>6～12 mm、整体直径范围内的角膜光密度采用随机区组方差分析，对术中切削深度、切削厚度与角膜光密度的关系采用Pearson相关分析。结果　术后1个月和术后6个月，不同组别患眼在同一直径范围内的角膜光密度相比差异均无统计学意义（均为P>0.05）；术后3个月，LASEK组患眼的角膜光密度在0～6 mm、>6～12 mm、整体直径范围内均显著低于SMILE组，在>6～12 mm、整体直径范围内均显著低于FS-LASIK组（均为P<0.05）；术后12个月，SMILE组患眼在0～6 mm、>6～12 mm、total直径范围内的角膜光密度均显著低于其他两组（均为P<0.05）。术后3个月，0～6 mm、>6～12 mm、total直径范围内的角膜光密度与术中角膜切削深度、切削厚度均呈正相关（均为P<0.05）；术后12个月，各直径范围内的角膜光密度与术中角膜切削深度、切削厚度均呈负相关（均为P<0.05）。结论　高度近视患者在行激光角膜屈光术后的早期修复中，SMILE术式的角膜透明性稍差，而LASEK术式则相对更佳，但SMILE术后患眼长期的角膜透明性更佳。角膜光密度与术中角膜的切削深度以及切削厚度密切相关。

Comparison of corneal optical density at different time after different laser keratomileusis

Objective　To investigate the comparisons and changes of corneal optical density in patients with high myopia at different times and diameters after small incision lenticule extraction (SMILE), femtosecond laser-assisted in situ keratomileusis (FS-LASIK) and laser subepithelial keratomileusis (LASEK), and their correlation with intraoperative cutting depth and thickness. Methods　In this prospective cohort study, 82 patients (164 eyes) with high myopia who were treated in the Department of Ophthalmology, Affiliated Hospital of Qingdao University, Shandong Province, were divided into the SMILE group (30 patients with 60 eyes), FS-LASIK group (27 patients with 54 eyes), and LASEK group (25 patients with 50 eyes) according to surgical methods. Pentacam examination was performed preoperatively and at 1 month, 3 months, 6 months and 12 months postoperatively. The corneal optical density within different diameter ranges (0-6 mm, >6-12 mm, and total) at the same time after surgery was analyzed by one-way analysis of variance with SPSS 22.0 statistical software, and its correlation with the intraoperative cutting depth and thickness was analyzed by Pearson.Results　There was no significant difference in corneal optical density within the same diameter range between different groups at 1 month and 6 months postoperatively (all P>0.05). Three months after surgery, the corneal optical density in the LASEK group was significantly lower than that in the SMILE group within the diameter ranges of 0-6 mm, >6-12 mm and total, and also lower than that in the FS-LASIK within the diameter ranges of >6-12 mm and total (all P<0.05). Twelve months after surgery, the corneal optical density within the diameter ranges of 0-6 mm, >6-12 mm and total in the SMILE group was significantly lower than that in the other two groups (all P<0.05). Three months after surgery, the corneal optical density within the diameter ranges of 0-6 mm, >6-12 mm and total was positively correlated with the cutting depth and thickness during the operation, while twelve months after surgery, the corneal optical density within the diameter ranges of 0-6 mm, >6-12 mm and total was negatively correlated with the cutting depth and thickness during the operation (all P<0.05).Conclusion　In the early repair, the corneal transparency of patients receiving SMILE surgery is poorer than that of patients receiving LASEK surgery. However, in the long run, the corneal transparency of patients receiving SMILE surgery is better. The corneal optical density is closely related to the cutting depth and thickness during the operation.