Koh Il Hwan, Seo Kyoung Yul, Park Seong Bae, Yang Hun, Kim InSik, Nam Sang Min
SU Yonsei Eye Clinic, Seoul, Republic of Korea.
Department of Ophthalmology, Institute of Vision Research, Eye and Ear Hospital, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
Graefes Arch Clin Exp Ophthalmol. 2018 Nov;256(11):2259-2268. doi: 10.1007/s00417-018-4074-x. Epub 2018 Jul 29.
To suggest that tear film is a refractive outcome predictor in small-incision lenticule extraction (SMILE) for myopia and describe methods of controlling the tear film and its effects on refractive outcomes.
In this retrospective case-control study, the tear film was kept clear and appropriate in amount during tear-film-controlled SMILE (TFC-SMILE). In contrast, no special care to the tear film was given in direct-docking SMILE (DD-SMILE). Both procedures were performed by the same experienced surgeon, using the same surgical parameters, over defined periods. In select cases, scanning electron microscopy (SEM) of the lenticule and surgical videos of opaque bubble layers (OBLs) were obtained and compared.
Forty-one eyes had DD-SMILE and 55 eyes had TFC-SMILE. Multivariate analysis showed that TFC-SMILE and the patient's age were significant predictors of refractive outcomes. The refractive predictability of TFC-SMILE was better than that of DD-SMILE, and under-correction of high myopia was evident in the latter patients. The predictive errors of DD-SMILE became more myopic and variable during 1 year than those of TFC-SMILE. The lenticular surface on SEM was more serrated in DD-SMILE. Severe OBLs were evident in four cases of DD-SMILE and the OBL pattern was sporadic at the anterior surface of the lenticule.
The presence of a clear and appropriate tear film in SMILE enhanced predictability, minimized variability, and ensured stability of refractive outcomes. An uncontrolled tear film might render cutting imprecise and trigger severe OBL formation. TFC-SMILE had more predictable results than DD-SMILE.
提示泪膜是近视小切口透镜切除术（SMILE）屈光结果的预测指标，并描述控制泪膜的方法及其对屈光结果的影响。
在这项回顾性病例对照研究中，在泪膜控制的SMILE（TFC-SMILE）过程中保持泪膜清晰且量合适。相比之下，直接对接SMILE（DD-SMILE）中未对泪膜进行特殊护理。这两种手术均由同一位经验丰富的外科医生在规定时间内使用相同的手术参数进行。在选定的病例中，获取并比较了透镜的扫描电子显微镜（SEM）图像和不透明气泡层（OBL）的手术视频。
41只眼接受了DD-SMILE，55只眼接受了TFC-SMILE。多变量分析表明，TFC-SMILE和患者年龄是屈光结果的重要预测指标。TFC-SMILE的屈光可预测性优于DD-SMILE，后者患者中高度近视欠矫明显。与TFC-SMILE相比，DD-SMILE的预测误差在1年内变得更加近视且变化更大。DD-SMILE中SEM显示的透镜表面锯齿状更明显。DD-SMILE的4例病例中可见严重的OBL，且OBL模式在透镜前表面呈散在分布。
SMILE中清晰且量合适的泪膜可提高可预测性，使变异性最小化，并确保屈光结果的稳定性。不受控制的泪膜可能导致切割不精确并引发严重的OBL形成。TFC-SMILE的结果比DD-SMILE更具可预测性。
