Background The surgery for femtosecond laser created laser in situ keratomileusis(LASIK)flaps has made great progression recent year,but the postoperative corneal wound healing and regeneration of nerve fibers after surgery are closely concerned.Objective This study was to compare and analyze the clinical outcomes between FEMTO LDV femtosecond laser flap and mechanical microkeratome Hansatome flap in LASIK.Methods A prospective case-controlled study was designed.The serial 38 myopic eyes of 38 patients were included from March through July,2010 in Henan Armed Police Force General Hospital.The patients were randomized into FEMTO LDV femtosecond laser assisted flap group(20 patients/20 eyes)and mechanical microkeratome Hansatome assisted flap group(18 patients/18 eyes)with the matched age,gender and refraction of spherical equivalent.HRT Ⅲ examinations were performed before surgery,1 week,1 month and 3 months after surgery to compare the morphological changes atthe center and margin of the flaps,and evaluate the similarities and differences of cellular morphology after surgery between the two approaches.Written informed consent was obtained from each patient prior to this medical trial.Results The best corrected visual acuity was ≥ 1.0 and the refract diopter was similar in both groups(+0.21 D±0.48 D and-0.04 D±0.54 D)1 month after LASIK.The corneal thickness was insignificant increased in the first week after LASIK,and the density of shallow stromal cells was decreased in 1 week,1 month and 3 months compared with pre-operation in the femtosecond laser assisted flap group(t =-27.99,-25.49,-28.87,P ＜ 0.01).In the Hansatome assisted flap group,significantly thickened corneal epithelium was seen in the first week after LASIK compared before LASIK(56.73 μm±2.47 μm versus 51.16 μm±1.11 μm)(t=9.29,P＜0.05),and the density of shallow stromal cells was decreased in 1 week,1 month and 3 months compared with pre-operation in the Hansatome assisted flap group(t =-17.57,-14.13,-19.63,P =0.00).The density of high reflective interface particles in cornea was lower in 1 week,1 month and 3 months after LASIK in the femtosecond laser assisted flap group than that in the Hansatome assisted flap group,showing significant differences between them(t =-13.505,-11.900,-14.084,P＜0.01).The active stromal cells were seen beneath the interface in both groups in the first week and gradually decreased after that time.Intact corneal nerve fibers were found in the femtosecond laser assisted flap group,but those in the Hansatome assisted flap group were shorter and smaller 3 months after LASIK.At 3 months after surgery,the flap margin showed stromal higher reflection and irregular secondary fibrosis in the femtosecond laser assisted flap group,and in contrast,the flap margin had the appearance of a unclearly identified fibrotic scar in the Hansatome assisted flap group.Conclusions Compared with the LASIK and Hansatome assisted flap,the LASIK with FEMTO LDV flap shows earlier nerve fiber regeneration and greater fibrotic scarring,which imply a good wound healing process in the LASIK with FEMTO LDV flap.%背景 飞秒激光制作准分子激光角膜原位磨镶术(LASIK)角膜瓣技术日渐成熟,术后角膜创伤愈合及神经纤维的再生成为关注热点.目的 对比分析FEMTO LDV飞秒激光及Hansatome机械角膜刀制瓣对LASIK后角膜细胞的影响.方法 采用前瞻性病例对照研究设计.纳入2010年3-7月在武警河南总队医院眼科连续收治的行LASIK的近视患者38例38眼,分为FEMTO LDV组20例20眼(采用FEMTOLDV飞秒激光制瓣)及Hansatome组18例18眼(采用Hansatome微型角膜刀制瓣),两组患者性别、年龄、术前等效球镜度等资料相匹配.分别于术前及术后1周、1个月、3个月应用共焦显微镜检测角膜中央及角膜瓣边缘的形态学变化,并比较两种制瓣方式术后角膜细胞形态学的异同.观察两组患者的术后视力、屈光度变化和裂隙灯下表现.结果 本研究中两组术眼术后1个月最佳矫正视力均≥1.0.FEMTO LDV组平均等效球镜度为(+0.21±0.48)D,Hansatome组为(-0.04±0.54)D,两组屈光度结果接近.FEMTO LDV组术后1周角膜上皮有增厚表现,但与术前比较差异无统计学意义(t=1.63,P＞0.05).FEMTO LDV组术后1周、1个月和3个月浅基质细胞密度较术前均明显减少,差异均有统计学意义(t=-27.99、-25.49、-28.87,P＜0.01).Hansatome组术后1周角膜上皮厚度为(56.73±2.47)μm,较术前值(51.16±1.11)μm明显增加,差异有统计学意义(t=9.29,P＜0.05),3个月时接近术前厚度；Hansatome组术后1周、1个月和3个月浅基质细胞密度较术前明显减少,差异均有统计学意义(t=-17.57、-14.13、-19.63,P=0.00).所有眼均可在切削面见到高反光颗粒,FEMTO LDV组术后1周、1个月和3个月切削面高反光颗粒密度均明显少于Hansatome组,差异均有统计学意义(t=-13.505、-11.900、-14.084,P＜0.01).术后1周时两组均观察到角膜细胞形态改变,切削界面后见激活的基质细胞,3个月时激活细胞减少.FEMTO LDV组术后3个月可见完整的神经纤维,而Hansatome组神经纤维短小.术后3个月,FEMTO LDV组周边角膜基质高反光,并有不规则纤维化,而Hansatome组角膜瓣边缘基质反光较弱.结论 与Hansatome机械角膜刀制瓣LASIK比较,FEMTO LDV飞秒激光制瓣LASIK术后神经纤维再生较早,角膜瓣边缘瘢痕化改变较明显,显示出较强的愈合过程.
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