Ocular Microsurgery & Laser Centre, Brandon, Man.; Eye Consultant Centre, Dubai, United Arab Emirates.
Department of Psychology, Brandon University, Brandon, Man.
Can J Ophthalmol. 2018 Aug;53(4):324-329. doi: 10.1016/j.jcjo.2017.11.005. Epub 2018 Apr 2.
To investigate the feasibility, effectiveness, and reproducibility of femtosecond laser (FSL) technology in different corneal cuts.
Experimental study at the Brandon Regional Health Centre.
Twenty two Human Cadaver eyes donated for research and supplied by the eye bank of Manitoba university.
In this experimental study, the effectiveness and reproducibility of FSL were investigated in different corneal cuts. The corneas were divided into 5 groups: group I for penetrating keratoplasty; group II for anterior lamellar keratoplasty; group III for corneal pockets for inlays; group IV for intracorneal ring tunnels; and group V for corneal cross-linking pockets. Our primary endpoint was the repeatability of planned versus obtained thickness and diameter of the cuts with FSL. A secondary endpoint was the effectiveness and ease of dissection, rated from 0-4, with 4 being the easiest and 0 the most difficult to dissect.
There was a high correlation between planned and obtained thickness (r = 0.997, p < 0.001) and diameter (r = 0.998, p < 0.001). Both were statistically significant. Linear regression analyses showed that the obtained thickness of corneal cuts in micrometers was significantly predicted by the planned thickness of corneal cuts in micrometers (β = 0.996, t = 56.47, p < 0.001). Likewise, the obtained diameter of corneal cuts in millimeters was significantly predicted by the planned diameter of corneal cuts in millimeters (β = 0.971, t = 70.85, p < 0.001). The surgeons gave 15 out of a total of 22 corneas (68.2%) the maximum score for ease of dissection (Grade 4), where no adhesions were found and the dissection was smooth and steady. Five corneas out of a total of 22 (22.7%) were given a score of 3 of 4 where minor adhesions were found. Two corneas out of a total of 22 (9.1%) were given a score of 2 of 4 where >1 adhesion was found, with some difficulty in separating the cut cornea from the bed. No corneas were given grade 1 or grade 0. No significant differences were obtained for the ease of dissection among the 5 surgery types using Kruskal-Wallis H test (H [4] = 4.971, p > 0.05).
The measured corneal-cut geometry correlated well with laser settings in a variety of full- and partial-thickness FSL corneal patterns, including different depths and diameters. This reproducible efficacy and measurement accuracy of the planned versus obtained cuts could have a favourable result on a variety of corneal surgeries. It also yields a favourable ease of dissection of the cut lenticule from the stromal bed.
研究飞秒激光（FSL）技术在不同角膜切口的可行性、有效性和可重复性。
布兰登地区医疗中心的实验研究。
曼尼托巴大学眼库捐赠的 22 个人体尸体眼球。
在这项实验研究中，研究了 FSL 在不同角膜切口的有效性和可重复性。角膜分为 5 组：组 I 为穿透性角膜移植术；组 II 为前板层角膜移植术；组 III 为角膜镶嵌口袋；组 IV 为角膜内环隧道；组 V 为角膜交联口袋。我们的主要终点是 FSL 计划与实际切割厚度和直径的可重复性。次要终点是切割的难易程度，评分从 0-4，4 表示最容易，0 表示最难。
计划与实际厚度（r = 0.997，p < 0.001）和直径（r = 0.998，p < 0.001）之间高度相关。这两个都是统计学上显著的。线性回归分析显示，角膜切割的实际厚度可以显著预测角膜切割的计划厚度（β=0.996，t=56.47，p < 0.001）。同样，角膜切割的实际直径也可以显著预测角膜切割的计划直径（β=0.971，t=70.85，p < 0.001）。22 个角膜中有 15 个（68.2%）被外科医生评为最容易切割（4 分），即没有粘连，切割过程平稳。22 个角膜中有 5 个（22.7%）被评为 3 分（4 分），即有轻微粘连。22 个角膜中有 2 个（9.1%）被评为 2 分（4 分），即有一个以上的粘连，分离切割角膜和床时有一定的困难。没有角膜被评为 1 级或 0 级。Kruskal-Wallis H 检验显示，5 种手术类型的切割难易程度无显著差异（H [4] = 4.971，p > 0.05）。
在各种全层和部分厚度的 FSL 角膜模式中，包括不同的深度和直径，测量的角膜切割几何形状与激光设置密切相关。这种对计划与实际切割的可重复性和测量精度的控制，可能会对各种角膜手术产生有利的结果。它还能使切割的透镜从基质床上顺利分离。
