Endothelial cell damage due to the impingement of fragments ofcrystalline lens under cataract surgery

超声乳化术是白内障手术中最常用的手术方法。术中，在人工晶状体植入眼内之前，先将晶状体破碎并吸出。晶状体碎片散在后房，可能冲击角膜内皮表面。这可能是白内障手术中内皮细胞丢失的一个原因，尽管到目前为止还没有详细阐明。利用立体图像分析技术测量了猪眼超声乳化术中碎片的三维运动轨迹，阐明了碎片撞击细胞损伤的过程。碎片的运动轨迹显示碎片被带入灌溉水的速度突然增加。碎片对角膜内皮表面的冲击在图像上很明显，碎片的最大速度约为100 mm/s。为了阐明碎片撞击对角膜内皮细胞的影响，将提取的猪眼角膜内皮细胞暴露于含有碎片的生理盐水射流中，并在镜面显微镜下观察。有碎片组细胞的最大损伤率为8%，明显大于无碎片组。损伤率越高，射流速度越大。

Phacoemulsification is most popular surgical method of cataract surgery. During operation, crystalline lens is fragmented and aspirated before insertion of the artificial lens is into intraocular. Here the fragments of crystalline lens are scattered in the posterior chamber and might impinge onto the endothelial surface of the cornea. This is a possible cause of the loss of the endothelial cell during the cataract surgery, although it was not clarified in detail so far. We measured the three-dimensional trajectory of the fragments while phacoemulsification in porcine eye by use of stereo image analysis, and clarified the process of cell damage by the impingement of the fragments. Trajectory of the fragments revealed sudden increase of the speed of the fragments which is entrained into the irrigation flow. The impingement of the fragments on the endothelial surface of the cornea was evident in the image, and the maximum speed of the fragments was about 100 mm/s.In order to clarify the influence of impingement of the fragments on the cells of corneal endothelium, corneal endothelium extracted from porcine eye was exposed to jet of physiological saline which contains the fragment, and observed by specular microscope. Maximum damage rate of the cell iwas 8% in the case with fragments, which was substantially larger than the case without fragments.Damage rate tends to become higher so that velocity of jet becomes larger.