SUBRETNAL TRANSPLANTION OF HUMAN AMNIOTIC MEMBRANE IN RABBITS

黄斑下手术切除年龄相关性黄斑变性的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。人羊膜是厚的基底膜，具有抗粘附特性，促进上皮形成，减少炎症、新生血管形成和纤维化。羊膜移植已被报道在眼表重建中是有效的。本实验采用兔视网膜下移植人羊膜，观察了视网膜色素上皮的重建。羊膜植入采用标准视网膜下手术和器械。每周检查一次，植入后1 ~ 4周，处死家兔进行组织学和免疫组织学研究CD 4和CD 8。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周时羊膜下PE增生。然而，在裸Bruch膜上没有观察到PE增殖。CD 4、CD 8阳性细胞在2周内出现，4周后下降。兔视网膜下羊膜免疫耐受实验表明，羊膜和视网膜下腔均为免疫豁免区。羊膜可以作为一个有用的替代在黄斑下手术。

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.