Linnola R J
J Cataract Refract Surg. 1997 Dec;23(10):1539-42. doi: 10.1016/s0886-3350(97)80026-0.
To present a bioactivity-based explanation for posterior capsule opacification (PCO) formation after cataract surgery.
Central Hospital, Vaasa, Finland.
The sandwich theory was based on findings in a keratoprosthesis study in which bioactivity of the prosthesis seemed to prevent epithelial downgrowth and clinical findings of the behavior of the AcrySof intraocular lens (IOL). The theory was formulated to explain PCO formation after cataract surgery with posterior chamber IOL implantation.
If the IOL were of a bioactive material, it would allow a single lens epithelial cell to bond both to the IOL and the posterior capsule. This would produce a sandwich pattern including the IOL, the cell monolayer, and the posterior capsule. The sealed sandwich structure might prevent further epithelial ingrowth and PCO.
The degree of IOL bioactivity could explain the difference in PCO and the neodymium:YAG rates with different IOL materials. In theory, a bioactive IOL would prevent PCO better than poly(methyl methacrylate) and silicone IOLs, which have good biocompatibility but are bioinert.
对白内障手术后后囊膜混浊（PCO）的形成提出基于生物活性的解释。
芬兰瓦萨中央医院。
三明治理论基于角膜移植研究中的发现，在该研究中，假体的生物活性似乎可防止上皮细胞内生，以及基于AcrySof人工晶状体（IOL）行为的临床发现。该理论旨在解释白内障手术后植入后房型IOL时PCO的形成。
如果IOL是生物活性材料，它将允许单个晶状体上皮细胞同时与IOL和后囊膜结合。这将产生一种三明治结构，包括IOL、细胞单层和后囊膜。密封的三明治结构可能会阻止上皮细胞进一步内生和PCO。
IOL生物活性程度可以解释不同IOL材料在PCO和钕:钇铝石榴石激光切开率方面的差异。理论上，生物活性IOL比聚甲基丙烯酸甲酯和硅酮IOL能更好地预防PCO，聚甲基丙烯酸甲酯和硅酮IOL具有良好的生物相容性但无生物活性。
