S1 Data -

Purpose
To evaluate the changes of the corneal epithelial thickness (ET) profile induced by combined small incision lenticule extraction and accelerated corneal collagen crosslinking (SMILE-xtra) for myopia compared with the standard small incision lenticule extraction (SMILE).
Setting
Nuri Eye Hospital, 61, Dunsan-ro, Seo-gu, Daejeon, 35233, Korea.
Design
Retrospective cross-sectional study.
Methods
Thirty-one myopic eye undergoing SMILE-xtra and control group of 36 myopic eyes undergoing SMILE were retrospectively analyzed. Spectral-domain optical coherence tomography (CIRRUS™ HD-OCT 5000, ZEISS, Dublin, CA) was used to measure corneal ET of 17 zones within the central 7-mm zone at preoperative, postoperative 1 month, 3 months and 6 months. Postoperative ET alterations were analyzed for correlation with treatment parameters.
Results
There was no difference in preoperative mean age, postoperative MRSE, visual acuity, and ablation depth between the two groups, and there was a significant difference in preoperative central corneal thickness. Both groups showed the greatest increase in corneal ET in the paracentral area on the inferotemporal area, respectively, for 6 months. The preoperative MRSE and the ablation depth showed significant correlation with the postoperative epithelial thickening in mid-peripheral sectors in both groups, and significant negative correlations in paracentral sectors only in SMILE-xtra group.
Conclusions
It is significant as the first study to compare corneal epithelial remodeling between SMILE and SMILE with accelerated corneal collagen crosslinking. The SMILE-xtra with the relatively large corneal ablation did not show a significant difference in the pattern of corneal epithelial remodeling compared to the SMILE group.

研究目的：评估近视患者接受联合加速角膜胶原交联的小切口角膜基质透镜取出术（SMILE-xtra）与标准小切口角膜基质透镜取出术（small incision lenticule extraction, SMILE）后，所诱导的角膜上皮厚度（epithelial thickness, ET）分布变化。
研究机构：韩国大田广域市西区敦山路61号，努里眼科医院（Nuri Eye Hospital），邮编35233。
研究设计：回顾性横断面研究。
研究方法：回顾性分析31眼接受SMILE-xtra治疗的近视患者，以及36眼接受标准SMILE治疗的近视患者作为对照组。采用光谱域光学相干断层扫描仪（CIRRUS™ HD-OCT 5000，蔡司ZEISS，美国加利福尼亚州都柏林），于术前、术后1个月、3个月及6个月，测量中央7mm范围内17个分区的角膜上皮厚度（ET）。并分析术后上皮厚度变化与治疗参数的相关性。
研究结果：两组患者术前平均年龄、术后等效球镜度数（mean refractive spherical equivalent, MRSE）、视力及切削深度均无显著差异，但术前中央角膜厚度存在显著差异。术后随访6个月期间，两组患者的角膜上皮厚度均在各自的颞下旁中央区域出现最显著的增厚。两组患者术前等效球镜度数与切削深度，均与中周边分区术后上皮增厚呈显著相关性；仅SMILE-xtra组的旁中央分区上皮增厚与上述指标呈显著负相关。
研究结论：本研究为首个对比标准SMILE与联合加速角膜胶原交联的SMILE术后角膜上皮重塑差异的研究，具有一定学术价值。相较于标准SMILE组，接受相对大范围角膜切削的SMILE-xtra组，其角膜上皮重塑模式并未出现显著差异。