Objectives To assess the clinical effectiveness of laser in situ keratomileusis (LASIK) versus laser epithelial keratomileusis (LASEK) for the correction of myopia. Methods Randomised controlled trials (RCTs) were searched in PubMed, EMbase, The Cochrane Library (Issue 2, 2010), CNKI, VIP, and WangFang Data from January, 1990 to October, 2010. The RCTs were included in accordance with the Cochrane review’s methodology, the valid data were extracted, the quality was evaluated, and then the RevMan 5.0 software was used for statistical analyses. Results Seven RCTs involving 1 134 eyes with myopia were included. The results of meta-analyses showed that the efficacy (OR=1.23, 95%CI 0.73 to 2.07), accuracy (OR=1.73, 95%CI 0.74 to 2.53) and safety (OR=1.10, 95%CI 0.22 to 5.59) outcomes between LASIK and LASEK were comparable. Compared with LASIK, LASEK was higher in the incidence rate of postoperative eye pain (RR=0.13, 95%CI 0.08 to 0.22). Conclusion LASIK and LASEK have the same effectiveness for myopia, but LASEK induces more postoperative eye pains. A large number of strictly-designed multi-centred RCTs are required for further verifying this result because of the low quality and instable results of the included studies．
目的:通过应用护理程序于准分子激光原位角膜磨镶术,使护理行为标准化,程序化,系统化,减少由于护理问题引发的手术并发症。方法:将100例患者随机分为常规组和程序组,分别对其实施单纯性健康宣教法和模拟训练,实地参观为一体的护理程序法,从评估,诊断,计划,实施,评价,五个方面科学实施,最终从焦虑指数,术中配合,术后满意率三个方面对两组效果进行评估。结果:常规组焦虑指数的SAS评分为42.49±1.63,程序组为32.78±1.56,两者之间有显著差异(t=9.89,Plt;0.01);术中常规组头位改变率13.27%(13/98),眼位变化率16.33%(16/98),程序组分别为3.06%(3/98)、2.04%(2/98),两者之间有显著差异(χ2=15.18,Plt;0.01);常规组术后7天裸眼视力大于或等于最佳矫正视力的常规组75眼(76.53%),程序组95眼(96.94%),两者之间有显著差异(X2=14.65,Plt;0.01)。结论:护理程序的实施规范了护士对准分子激光原位角膜磨镶术的全程护理,取得了较好的临床效果。
The decrease of corneal stiffness is the key factor leading to keratoconus, and the corneal collagen fiber stiffness and fiber dispersion are closely related to the corneal biomechanical properties. In this paper, a finite element model of human cornea based on corneal microstructure, namely collagen fiber, was established before and after laser assisted in situ keratomileusis (LASIK). By simulating the Corvis ST process and comparing with the actual clinical results, the hyperelastic constitutive parameters and corneal collagen fiber stiffness modulus of the corneal material were determined before and after refractive surgery. After LASIK, the corneal collagen fiber stiffness modulus increased significantly, and was highly correlated with central corneal thickness (CCT). The predictive relationship between the corneal collagen fiber stiffness modulus and the corresponding CCT before and after surgery was: k1 before = exp(9.14 − 0.009CCTbefore), k1 after = exp(8.82 − 0.008CCTafter). According to the results of this study, the central corneal thickness of the patient can be used to estimate the preoperative and postoperative collagen fiber stiffness modulus, and then a personalized corneal model that is more consistent with the actual situation of the patient can be established, providing a theoretical reference for more accurately predicting the safe surgical cutting amount of the cornea.