经上皮准分子激光角膜切削术治疗低中度近视术后中央角膜上皮厚度的变化

目的:观察低中度近视患者行经上皮准分子激光角膜切削术(TPRK)后中央角膜上皮厚度(CCET)的变化。方法:回顾性系列病例研究。收集中国中医科学院眼科医院屈光手术科2015年1月至2016年6月间行TPRK手术的近视患者62例(114眼),按等效球镜度(SE)分为低度近视组(-3.00^-1.25D)和中度近视组(-6.00^-3.25D)。观察2组患者术前,术后1周、2周、1个月、3个月、6个月及1年的裸眼视力(UCVA)、SE、CCET的变化。采用两独立样本t检验、重复测量设计资料的方差分析比较2组术前、术后各时间点各参数的变化。结果:2组术前UCVA、SE比较差异均具有统计学意义(t=6.605,P=0.01;t=15.374,P=0.01),最佳矫正视力(BCVA)、CCET比较差异均无统计学意义(P>0.05)。2组间术后1周CCET比较差异有统计学意义(t=3.362,P=0.01),且低度近视组较中度近视组大,但术后其他观察时间点两两比较差异均无统计学意义(均P>0.05)。2组间及组内术后各观察时间点UCVA及SE比较差异均无统计学意义(均P>0.05)。2组内CCET除术后1个月与2周,术后6个月、1年与术前比较差异无统计学意义(均P>0.05)外,其余时间点比较差异均具有统计学意义(均P<0.05)。结论:TPRK术后早期低度近视组CCET较中度近视组恢复快;2组CCET均于术后6个月恢复至术前水平并维持稳定;TPRK手术治疗低中度近视具有较高的术后视力可预测性和屈光度数的稳定性。

Changes in Central Corneal Epithelial Thickness after Transepithelial Photorefractive Keratectomy for Low and Moderate Myopia

Objective: To observe the changes in the central corneal epithelium thickness (CCET) after transepithelial photorefractive keratectomy (TPRK) in low and moderate myopia patients. Methods: This was a retrospective case series study. Sixty-two myopes (114 eyes) were recruited who underwent TPRK at the Eye Hospital of China Academy of Traditional Chinese Medicine from January 2015 to June2016. Patients were divided into two groups based on spherical equivalence (SE) refractive error: a low myopia group (-3.00 D to -1.25 D) and a moderate myopia group (-6.00 D to -3.25 D). Both groups underwent testing for uncorrected visual acuity (UCVA), SE, and CCET and were compared preoperatively and postoperatively at 1 week, 2 weeks, 1 month, 3 months, 6 months and 1 year. Preoperative and postoperative changes were analyzed with two independent samples t tests and repeated measures analysis of variance. Results: The two groups had significant differences in both UCVA and SE preoperatively(t=6.605, P=0.01; t=15.374, P=0.01). There were no significant differences between BCVA and CCET preoperatively (both P>0.05). The CCET values for the low myopia group were relatively higher than that for the moderate myopia group 1 week postoperation (t=3.362, P=0.01), but there were no significant differences at the other time points. Between the two groups and within each group at postoperative observation time points, UCVA and SE were not statistically significant. For CCET, except for between postoperative 1 month and 2 weeks, between postoperative 6 months, 1 year and preoperative without difference. And there was with difference between time points (P<0.05). Conclusions: In the early stage after TPRK, CCET in the low myopia group recovers faster than that in the moderate myopia group. The CCET in both groups is restored to preoperative levels after 6 months, and remains stable. TPRK surgical treatments for visual acuity in low and moderate myopia has a high predictability and a stable SE.