Ectasia following small-incision lenticule extraction (SMILE): a review of the literature.
Ectasia following small-incision lenticule extraction (SMILE): a review of the literature.
复制标题
DOI：
10.2147/opth.s147011
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
Hoopes PC Sr
中科院分区：
文献类型：
--
作者：
Moshirfar M;Albarracin JC;Desautels JD;Birdsong OC;Linn SH;Hoopes PC Sr
报告了四例小切口微透镜摘除术（SMILE）后角膜扩张的病例。在这篇综述中，我们对已发表的关于SMILE术后角膜扩张的文献以及与该并发症相关的风险因素进行了综述。通过检索2011年至2017年7月期间的7个电子数据库中的相关标题术语来识别病例报告。我们确定了患者的特征和手术细节，包括术前地形图，中央角膜厚度和前角膜曲率（Km）。使用VisuMax ReLEx SMILE软件版本2.10.10计算未报告的残留基质床（RSB）值。采用兰德莱曼扩张风险评分系统（ERSS）测量术前扩张风险。如Santhiago等人所述，计算每例患者的组织改变百分比。4例患者的7只眼在SMILE后发生角膜扩张。2例患者双眼地形图异常。1例患者的一只眼有异常地形图。仅1例患者的双眼地形图正常，后来在无任何已知风险因素的情况下，一只眼睛出现扩张。平均兰德莱曼扩张风险评分为4±3（范围：1-8）。平均计算的组织改变百分比（PTA）为38%±6%（范围：30%-47%）。大多数报告的扩张病例发生在亚临床圆锥角膜患者中。SMILE可能会加剧这些情况，应视为该手术的绝对禁忌症。根据ERSS，3例患者被确定为高风险，1例患者显示PTA ≥ 40%。我们对当前PTA的计算进行了修改，考虑到SMILE和激光原位角膜磨镶术（LASIK）之间组织改变的差异。需要更多的研究来充分量化扩张的风险。目前，我们建议在SMILE手术中采用与LASIK相同的排除标准，直到更具体的指标得到验证。
Four cases of corneal ectasia after small-incision lenticule extraction (SMILE) have been reported. In this review, we provide an overview of the published literature on corneal ectasia after SMILE and risk factors associated with this complication. Case reports were identified by a search of seven electronic databases for pertinent heading terms between 2011 and July 2017. We identified patient characteristics and surgical details including preoperative topography, central corneal thickness, and anterior keratometry (Km). Residual stromal bed (RSB) values not reported were computed using VisuMax ReLEx SMILE software Version 2.10.10. Preoperative ectasia risk was measured using the Randleman Ectasia Risk Score System (ERSS). Percent tissue alteration was calculated for each patient as described by Santhiago et al. Seven eyes of four patients developed corneal ectasia post SMILE. Two patients had abnormal topography in both eyes. One patient had abnormal topography in one eye. Only one patient was noted to have normal topography in both eyes and later developed ectasia in one eye in the absence of any known risk factors. The mean Randleman ectasia risk score was 4±3 (range: 1–8). The mean calculated percent tissue altered (PTA) was 38%±6% (range: 30%–47%). A majority of reported ectasia cases occurred in patients with subclinical keratoconus. These conditions may be exacerbated by SMILE and should be considered absolute contraindications to the procedure. Three patients were identified to have high risk based on the ERSS, and one patient exhibited a PTA ≥40%. We formulated a modification to the current calculation of PTA that takes into account the differences in tissue altered between SMILE and laser in situ keratomileusis (LASIK). More studies are needed to fully quantify the risk of ectasia. For now, we propose adopting the same exclusion criteria used for LASIK in the SMILE procedure until more specific metrics have been validated.