Centre for Sight, East Grinstead, UK
Singapore National Eye Centre, Singapore, Singapore.
Br J Ophthalmol. 2020 Mar;104(3):437-442. doi: 10.1136/bjophthalmol-2018-313421. Epub 2019 Apr 4.
To compare the anterior capsulotomy edge tear strength created by manual continuous curvilinear capsulorhexis (CCC), femtosecond laser-assisted capsulotomy (FLACS), and selective laser capsulotomy (SLC).
Singapore National Eye Centre, Singapore and Excel-Lens, Livermore, California, USA.
Three armed study in paired human eyes.
Capsulotomies were performed in 60 cadaver eyes of 30 donors using CCC, Victus Femtosecond Laser, (Bausch & Lomb, Rochester, New York, USA) or CAPSULaser, (Excel-Lens, Los Gatos, California, USA). Three pairwise study groups each involved 10 pairs of eyes. Study group 1: SLC eyes compared with fellow eyes with CCC. Study group 2: CCC eyes compared with fellow eyes with FLACS. Study group 3: FLACS eyes compared with fellow eyes with SLC.A shoe-tree method was used to apply load to the capsulotomy edge, and Instron tensile stress instrument measured distension and threshold load applied to initiate capsule fracture. Relative fracture strengths and distension of CCC, FLACS and SLC were determined. Scanning electron microscopy (SEM) of capsule edges were reviewed RESULTS: Anterior capsulotomies behave as non-linear elastic (elastomeric) systems when exposed to an external load. The pairwise study demonstrated that the SLC fracture strength was superior to that of CCC by a factor of 1.46-fold with SLC 277±38 mN versus CCC with 190±37 mN. Furthermore, CCC fracture strength was superior to that of FLACS by a factor of 1.28-fold with CCC 186 + 37 mN versus FLACS 145 ± 35 mN (p < 0.001). This was determined by statistical analysis utilising the Wilcoxon matched-pairs signed-ranks test and in accordance with the Consolidated Standards of Reporting Trials guidelines. The capsule edge of SLC on SEM demonstrated a rolled over edge anteriorly and an alteration of collagen.
The strength of the capsulotomy edge for SLC was significantly stronger than that of CCC which and both were significantly stronger than FLACS. The relative strengths can be explained by SEM of each type of capsulotomy.
比较手动连续曲线撕囊术（CCC）、飞秒激光辅助撕囊术（FLACS）和选择性激光撕囊术（SLC）所产生的前囊膜切缘撕裂强度。
新加坡国家眼科中心和美国加利福尼亚州利弗莫尔的 Excel-Lens。
在 30 名供体的 60 只尸体眼球中进行了三项有对照的研究。
使用 CCC、Victus 飞秒激光（Bausch & Lomb，纽约罗切斯特）或 CAPSLaser（Excel-Lens，加利福尼亚州洛斯加托斯）在 60 只尸体眼球中进行撕囊术。每组 3 个配对研究，每组 10 对眼球。研究组 1：SLC 眼与 CCC 对侧眼比较。研究组 2：CCC 眼与 FLACS 对侧眼比较。研究组 3：FLACS 眼与 SLC 对侧眼比较。采用鞋楦法对囊膜切缘施加负荷，Instron 拉伸应力仪测量囊膜扩张和引发囊膜破裂的阈值负荷。确定 CCC、FLACS 和 SLC 的相对断裂强度和扩张度。评估囊膜边缘的扫描电子显微镜（SEM）结果。
当受到外部负荷时，前囊膜撕囊术表现为非线性弹性（弹性体）系统。配对研究表明，SLC 的断裂强度是 CCC 的 1.46 倍，SLC 为 277±38 mN，而 CCC 为 190±37 mN。此外，CCC 的断裂强度是 FLACS 的 1.28 倍，CCC 为 186 + 37 mN，而 FLACS 为 145 ± 35 mN（p < 0.001）。这是通过利用 Wilcoxon 配对符号秩检验进行的统计学分析确定的，并符合 CONSORT 报告试验标准。SLC 囊膜边缘的 SEM 显示前部边缘有一个滚边，胶原发生改变。
SLC 囊膜切缘的强度明显强于 CCC，而 CCC 和 SLC 的强度均明显强于 FLACS。相对强度可以通过每种类型的撕囊术的 SEM 来解释。
