Zadnik Karla, Money Sarah, Lindsley Kristina
College of Optometry, The Ohio State University, 338 West Tenth Avenue, Columbus, Ohio, USA, OH 43210.
Cochrane Database Syst Rev. 2019 May 14;5(5):CD011150. doi: 10.1002/14651858.CD011150.pub2.
Keratoconus is a degenerative condition of the cornea that profoundly affects vision and vision-specific quality of life. The axial cornea thins and protrudes, resulting in irregularity and, eventually, scarring of the cornea. There are multiple options available for treating keratoconus. Intrastromal corneal ring segments are small, crescent-shaped plastic rings that are placed in the deep, peripheral corneal stroma in order to flatten the cornea. They are made of polymethylmethacrylate (PMMA). The procedure does not involve corneal tissue nor does it invade the central optical zone. Intrastromal corneal ring segments are approved for use when contact lenses or spectacles are no longer adequate.
To evaluate the effectiveness and safety of intrastromal corneal ring segments as a treatment for keratoconus.
We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Trials Register) (2018, Issue 1); Ovid MEDLINE; Embase.com; PubMed; Latin American and Caribbean Health Sciences Literature Database (LILACS); ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We did not implement any date or language restrictions in the electronic search for trials. We last searched the electronic databases on 25 January 2018.
Two review authors independently assessed records from the electronic searches to identify randomized controlled trials (RCTs). Disagreements were resolved by discussion.
We planned for two authors to independently review full-text reports, using standard methodological procedures expected by Cochrane.
We found no RCTs comparing intrastromal corneal ring segments with spectacles or contact lenses.
AUTHORS' CONCLUSIONS: In the absence of eligible RCTs to review, no conclusions can be drawn.
圆锥角膜是一种角膜退行性疾病，会严重影响视力以及与视力相关的生活质量。角膜中央变薄并向前突出，导致角膜不规则，最终形成瘢痕。圆锥角膜有多种治疗方法。角膜基质内环形片段是小型新月形塑料环，放置于周边深层角膜基质中以使角膜变平。它们由聚甲基丙烯酸甲酯（PMMA）制成。该手术不涉及角膜组织，也不侵入中央光学区。当隐形眼镜或眼镜不再适用时，角膜基质内环形片段被批准使用。
评估角膜基质内环形片段治疗圆锥角膜的有效性和安全性。
我们检索了Cochrane对照试验中心注册库（CENTRAL）（其中包含Cochrane眼科和视力试验注册库）（2018年第1期）；Ovid MEDLINE；Embase.com；PubMed；拉丁美洲和加勒比健康科学文献数据库（LILACS）；ClinicalTrials.gov以及世界卫生组织（WHO）国际临床试验注册平台（ICTRP）。在电子检索试验时，我们未设置任何日期或语言限制。我们最近一次检索电子数据库的时间为2018年1月25日。
两位综述作者独立评估电子检索记录，以识别随机对照试验（RCT）。分歧通过讨论解决。
我们计划让两位作者使用Cochrane期望的标准方法程序独立审查全文报告。
我们未找到比较角膜基质内环形片段与眼镜或隐形眼镜的RCT。
由于缺乏符合条件可供审查的RCT，无法得出结论。
