SUBRETNAL TRANSPLANTION OF HUMAN AMNIOTIC MEMBRANE IN RABBITS

对于老年性黄斑变性患者，采用黄斑下手术去除脉络膜新生血管可以改善或稳定部分患者的视力。然而，视网膜色素上皮经常受损，导致视力不良。人羊膜是厚厚的基底膜，具有抗粘连特性，促进上皮化，减少炎症、新生血管形成和纤维化。羊膜移植是一种有效的眼表重建方法。利用兔模型，研究了人羊膜植入视网膜下后视网膜色素上皮的重建。采用标准的视网膜下手术及器械完成羊膜植入。每周检查一次，植入后1~4周处死动物，进行组织学和免疫组织学研究。未发现炎症、纤维蛋白、视网膜水肿、视网膜脱离。视网膜重新附着在羊膜上。组织学检查显示2周后羊膜下可见PE增生。而在裸露的Bruch膜上未见PE的增殖。CD4、CD8阳性细胞在2周时出现，4周时下降。人视网膜下羊膜对兔的耐受性实验表明，羊膜和视网膜下腔均为免疫特异区。在黄斑下手术中，羊膜可以作为一种有用的替代物。

Submacular surgery for the removal of choroidal neovasucularization in age related macular degeneration can improve or sstabilize vision in selected partients. However, the retinal pigment epithelium are frequently damaged and contribute to the poor visual outcome. Human amniotic membrane is thick basement membrane and has anti-adhesive properties and promote epithelialization and decrease inflammation, neovasucularization, and fibrosis. Amniotic membrane transplantation has been reported to be effective in the reconstruction of the ocular surface. Using rabbit model, we have investigated the reconstruction of retinal pigment epithelium following subretinal implantation of human amniotic membrane. The implantation of amniotic membrane was achieved using standard subretinal surgery and instrument. Weekly examination was performed and 1 to 4 weeks after implantation, rabbits were sacrificed for histological and immune histological study of CD4 and CD8. No evidence of inflammation, fibrin, retinal edema, retinal detachment was detected. The retina reattached over the amniotic membrane. Histological cvaluation revealed PE proliferation under the amniotic membrane in 2 weeks. However, PE proliferation did not observed over bare Bruch's membrane. The CD4 and CD8 positive cells were observed in 2 weeks, but decreased in 4 weeks. The tolerance of subretinal human amniotic membrane in rabbits showed both amniotic membrane and subretinal space are immune-privileged site. The amniotic membrane may serve as a useful replacement during submacular surgery.