Kahuam-López Nicolás, Navas Alejandro, Castillo-Salgado Carlos, Graue-Hernandez Enrique O, Jimenez-Corona Aida, Ibarra Antonio
Universidad Anáhuac México, Campus Norte, Centro de Investigación en Ciencias de la Salud (CICSA), Facultad de Ciencias de la Salud, Av. Universidad Anáhuac 46, Huixquilucan, Mexico, Mexico, 52786.
Instituto de Oftalmología Fundación Conde de Valenciana, Cornea and Refractive Surgery Department, Chimalpopoca 14, Mexico City, Mexico City, Mexico, 06800.
Cochrane Database Syst Rev. 2020 Apr 7;4(4):CD012946. doi: 10.1002/14651858.CD012946.pub2.
Laser-assisted in-situ keratomileusis (LASIK) is a surgical procedure that corrects refractive errors. This technique creates a flap of the outermost parts of the cornea (epithelium, bowman layer, and anterior stroma) to expose the middle part of the cornea (stromal bed) and reshape it with excimer laser using photoablation. The flaps can be created by a mechanical microkeratome or a femtosecond laser.
To compare the effectiveness and safety of mechanical microkeratome versus femtosecond laser in LASIK for adults with myopia.
We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2019, Issue 2); Ovid MEDLINE; Embase; PubMed; LILACS; ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We used no date or language restrictions. We searched the reference lists of included trials. We searched the electronic databases on 22 February 2019.
We included randomized controlled trials (RCTs) of LASIK with a mechanical microkeratome compared to a femtosecond laser in people aged 18 years or older with more than 0.5 diopters of myopia or myopic astigmatism.
We used standard methodological procedures expected by Cochrane.
We included 16 records from 11 trials enrolling 943 adults (1691 eyes) with spherical or spherocylindrical myopia, who were suitable candidates for LASIK. Five hundred and forty-seven participants (824 eyes) received LASIK with a mechanical microkeratome and 588 participants (867 eyes) with a femtosecond laser. Each trial included between nine and 360 participants. In six trials, the same participants received both interventions. Overall, the trials were at an uncertain risk of bias for most domains. At 12 months, data from one trial (42 eyes) indicates no difference in the mean uncorrected visual acuity (logMAR scale) between LASIK with a mechanical microkeratome and LASIK with a femtosecond laser (mean difference (MD) -0.01, 95% confidence interval (CI) -0.06 to 0.04; low-certainty evidence). Similar findings were observed at 12 months after surgery, regarding participants achieving 0.5 diopters within target refraction (risk ratio (RR) 0.97, 95% CI 0.85 to 1.11; 1 trial, 79 eyes; low-certainty evidence) as well as mean spherical equivalent of the refractive error 12 months after surgery (MD 0.09, 95% CI -0.01 to 0.19; 3 trials, 168 eyes [92 participants]; low-certainty evidence). Based on data from three trials (134 eyes, 66 participants), mechanical microkeratome was associated with lower risk of diffuse lamellar keratitis compared with femtosecond laser (RR 0.27, 95% CI 0.10 to 0.78; low-certainty evidence). Thus, diffuse lamellar keratitis was a more common adverse event with femtosecond laser than with mechanical microkeratome, decreasing from an assumed rate of 209 per 1000 people in the femtosecond laser group to 56 per 1000 people in the mechanical microkeratome group. Data from one trial (183 eyes, 183 participants) indicates that dry eye as an adverse event may be more common with mechanical microkeratome than with femtosecond laser, increasing from an assumed rate of 80 per 1000 people in the femtosecond laser group to 457 per 1000 people in the mechanical microkeratome group (RR 5.74, 95% CI 2.92 to 11.29; low-certainty evidence). There was no evidence of a difference between the two groups for corneal haze (RR 0.33, 95% CI 0.01 to 7.96; 1 trial, 43 eyes) and epithelial ingrowth (RR 1.04, 95% CI 0.11 to 9.42; 2 trials, 102 eyes [50 participants]). The certainty of evidence for both outcomes was very low.
AUTHORS' CONCLUSIONS: Regarding the visual acuity outcomes, there may be no difference between LASIK with mechanical microkeratome and LASIK with femtosecond laser. Dry eye and diffuse lamellar keratitis are likely adverse events with mechanical microkeratome and femtosecond laser, respectively. The evidence is uncertain regarding corneal haze and epithelial ingrowth as adverse events of each intervention. The limited number of outcomes reported in the included trials, some with potentially significant risk of bias, makes it difficult to draw a firm conclusion regarding the effectiveness and safety of the interventions investigated in this review.
准分子原位角膜磨镶术（LASIK）是一种矫正屈光不正的外科手术。该技术制作一个角膜最外层部分（上皮层、Bowman层和前基质层）的瓣，以暴露角膜中间部分（基质床），并用准分子激光通过光消融对其进行重塑。瓣可以通过机械微型角膜刀或飞秒激光制作。
比较机械微型角膜刀与飞秒激光在成人近视LASIK手术中的有效性和安全性。
我们检索了Cochrane中心对照试验注册库（CENTRAL）（其中包含Cochrane眼科和视力试验注册库）（2019年第2期）；Ovid MEDLINE；Embase；PubMed；LILACS；ClinicalTrials.gov和世界卫生组织（WHO）国际临床试验注册平台（ICTRP）。我们没有设置日期或语言限制。我们检索了纳入试验的参考文献列表。我们于2019年2月22日检索了电子数据库。
我们纳入了18岁及以上、近视或近视散光超过0.5屈光度的人群中，比较使用机械微型角膜刀与飞秒激光进行LASIK手术的随机对照试验（RCT）。
我们采用了Cochrane期望的标准方法程序。
我们纳入了11项试验的16条记录，共943名成人（1691只眼）患有球面或球柱面近视，这些人是LASIK手术的合适候选者。547名参与者（824只眼）接受了机械微型角膜刀LASIK手术，588名参与者（867只眼）接受了飞秒激光LASIK手术。每项试验纳入9至360名参与者。在6项试验中，相同的参与者接受了两种干预。总体而言，大多数领域的试验存在偏倚风险不确定。在12个月时，一项试验（42只眼）的数据表明，机械微型角膜刀LASIK手术与飞秒激光LASIK手术之间的平均未矫正视力（logMAR量表）无差异（平均差（MD）-0.01，95%置信区间（CI）-0.06至0.04；低确定性证据）。在术后12个月，关于参与者在目标屈光范围内达到0.5屈光度的情况（风险比（RR）0.97，95%CI 0.85至1.11；1项试验，79只眼；低确定性证据）以及术后12个月屈光不正的平均球镜当量（MD 0.09，95%CI -0.01至0.19；3项试验，168只眼[92名参与者]；低确定性证据）也观察到了类似结果。基于三项试验（134只眼，66名参与者）的数据，与飞秒激光相比，机械微型角膜刀发生弥漫性层间角膜炎的风险较低（RR 0.27，95%CI 0.10至0.78；低确定性证据）。因此，弥漫性层间角膜炎在飞秒激光组中是比机械微型角膜刀组更常见的不良事件，从飞秒激光组每1000人中假设的209例发生率降至机械微型角膜刀组每1000人中的56例。一项试验（183只眼，183名参与者）的数据表明，作为不良事件，机械微型角膜刀导致的干眼可能比飞秒激光更常见，从飞秒激光组每1000人中假设的80例发生率增加到机械微型角膜刀组每1000人中的457例（RR 5.74，95%CI 2.92至11.29；低确定性证据）。两组在角膜 haze（RR 0.33，95%CI 0.01至7.96；1项试验，43只眼）和上皮内生（RR 1.04，95%CI 0.11至9.42；2项试验，102只眼[50名参与者]）方面没有差异的证据。这两个结果的证据确定性都非常低。
关于视力结果，机械微型角膜刀LASIK手术和飞秒激光LASIK手术之间可能没有差异。干眼和弥漫性层间角膜炎分别可能是机械微型角膜刀和飞秒激光的不良事件。关于角膜 haze和上皮内生作为每种干预的不良事件的证据不确定。纳入试验中报告的结果数量有限，有些存在潜在的显著偏倚风险，因此难以就本综述中研究的干预措施的有效性和安全性得出确凿结论。
