Barsam Allon, Allan Bruce D S
Moorfields Eye Hospital NHS Foundation Trust, City Road, London, UK, EC1V 2PD.
Cochrane Database Syst Rev. 2014 Jun 17;2014(6):CD007679. doi: 10.1002/14651858.CD007679.pub4.
Myopia is a condition in which the focusing power (refraction) of the eye is greater than that required for clear distance vision. There are two main types of surgical correction for moderate to high myopia; excimer laser and phakic intraocular lenses (IOLs). Excimer laser refractive surgery for myopia works by removing corneal stroma to lessen the refractive power of the cornea and to bring the image of a viewed object into focus onto the retina rather than in front of it. Phakic IOLs for the treatment of myopia work by diverging light rays so that the image of a viewed object is brought into focus onto the retina rather than in front of the retina. They can be placed either in the anterior chamber of the eye in front of the iris or in the posterior chamber of the eye between the iris and the natural lens.
To compare excimer laser refractive surgery and phakic IOLs for the correction of moderate to high myopia by evaluating postoperative uncorrected visual acuity, refractive outcome, potential loss of best spectacle corrected visual acuity (BSCVA) and the incidence of adverse outcomes.
We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 1), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to February 2014), EMBASE (January 1980 to February 2014), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 11 February 2014.
We included randomised controlled trials (RCTs) comparing excimer laser refractive surgery and phakic IOLs for the correction of myopia greater than 6.0 diopters (D) spherical equivalent.
Two authors independently assessed trial quality and extracted data. We performed data analysis. We summarised data for outcomes using odds ratios. We used a fixed-effect model as only three trials were included in the review.
This review included three RCTs with a total of 228 eyes. The range of myopia of included patients was -6.0 D to -20.0 D of myopia with up to 4.0 D of myopic astigmatism. The percentage of eyes with uncorrected visual acuity (UCVA) of 20/20 or better at 12 months postoperative was not significantly different between the two groups. Phakic IOL surgery was safer than excimer laser surgical correction for moderate to high myopia as it results in significantly less loss of best spectacle corrected visual acuity (BSCVA) at 12 months postoperatively. However there is a low risk of developing early cataract with phakic IOLs. Phakic IOL surgery appears to result in better contrast sensitivity than excimer laser correction for moderate to high myopia. Phakic IOL surgery also scored more highly on patient satisfaction/preference questionnaires.
AUTHORS' CONCLUSIONS: The results of this review suggest that, at one year post surgery, phakic IOLs are safer than excimer laser surgical correction for moderate to high myopia in the range of -6.0 to -20.0 D and phakic IOLs are preferred by patients. While phakic IOLs might be accepted clinical practice for higher levels of myopia (greater than or equal to 7.0 D of myopic spherical equivalent with or without astigmatism), it may be worth considering phakic IOL treatment over excimer laser correction for more moderate levels of myopia (less than or equal to 7.0 D of myopic spherical equivalent with or without astigmatism). Further RCTs adequately powered for subgroup analysis are necessary to further elucidate the ideal range of myopia for phakic IOLs. This data should be considered alongside comparative data addressing long-term safety as it emerges.
近视是一种眼睛的聚焦能力（屈光）大于清晰远视力所需能力的病症。对于中度至高度近视，主要有两种手术矫正方式：准分子激光手术和有晶状体眼人工晶状体（IOL）植入术。准分子激光近视屈光手术通过去除角膜基质来降低角膜的屈光力，使所视物体的图像聚焦在视网膜上而非视网膜前方。用于治疗近视的有晶状体眼人工晶状体通过使光线发散起作用，从而使所视物体的图像聚焦在视网膜上而非视网膜前方。它们可置于眼睛前房内虹膜前方或眼睛后房内虹膜与自然晶状体之间。
通过评估术后未矫正视力、屈光结果、最佳矫正视力（BSCVA）的潜在丧失以及不良后果的发生率，比较准分子激光屈光手术和有晶状体眼人工晶状体用于矫正中度至高度近视的效果。
我们检索了Cochrane中心对照临床试验注册库（CENTRAL）（2014年第1期，其中包含Cochrane眼科和视力组试验注册库）、Ovid MEDLINE、Ovid MEDLINE在研及其他非索引引文、Ovid MEDLINE每日更新、Ovid OLDMEDLINE（1946年1月至2014年2月）、EMBASE（1980年1月至2014年2月）、对照试验元注册库（mRCT）（www.controlled-trials.com）、ClinicalTrials.gov（www.clinicaltrials.gov）以及世界卫生组织（WHO）国际临床试验注册平台（ICTRP）（www.who.int/ictrp/search/en）。在电子检索试验时，我们未使用任何日期或语言限制。我们最后一次检索电子数据库的时间为2014年2月11日。
我们纳入了比较准分子激光屈光手术和有晶状体眼人工晶状体用于矫正等效球镜度数大于6.0屈光度（D）近视的随机对照试验（RCT）。
两位作者独立评估试验质量并提取数据。我们进行了数据分析。我们使用比值比总结结局数据。由于本综述仅纳入了三项试验，我们采用固定效应模型。
本综述纳入了三项RCT，共228只眼。纳入患者的近视范围为-6.0 D至-20.0 D近视，伴有高达4.0 D的近视散光。术后12个月时，两组未矫正视力（UCVA）达到20/20或更好的眼的百分比无显著差异。对于中度至高度近视，有晶状体眼人工晶状体手术比准分子激光手术矫正更安全，因为术后12个月时其导致的最佳矫正视力（BSCVA）丧失显著更少。然而，有晶状体眼人工晶状体植入术后早期发生白内障的风险较低。对于中度至高度近视，有晶状体眼人工晶状体手术似乎比准分子激光矫正具有更好的对比敏感度。有晶状体眼人工晶状体手术在患者满意度/偏好问卷上的得分也更高。
本综述结果表明，术后一年时，对于-6.0至-20.0 D范围内的中度至高度近视，有晶状体眼人工晶状体比准分子激光手术矫正更安全，且患者更倾向于选择有晶状体眼人工晶状体。虽然有晶状体眼人工晶状体可能是更高程度近视（等效球镜度数大于或等于7.0 D近视，伴有或不伴有散光）的可接受临床治疗方法，但对于更中度的近视（等效球镜度数小于或等于7.0 D近视，伴有或不伴有散光），与准分子激光矫正相比，有晶状体眼人工晶状体治疗可能值得考虑。需要进一步进行有足够样本量用于亚组分析的RCT，以进一步阐明有晶状体眼人工晶状体的理想近视范围。随着长期安全性比较数据的出现，应结合这些数据来考虑本研究数据。
