兔眼角膜后弹力层撕除角膜内皮移植术后排斥反应的研究

Corneal allograft rejection after descemet's stripping with endothelial keratoplasty in rabbit model

目的通过高危兔眼模型分析角膜后弹力层撕除角膜内皮移植术后效果及免疫排斥反应特点。方法根据手术方法的不同将28只兔分成2组:穿透性角膜移植组(PK组)和角膜后弹力层撕除角膜内皮移植组(DSEK组),每组各14只,右眼为手术眼。术后用裂隙灯检查角膜混浊、水肿和新生血管情况,并记录排斥指数(rejection index,RI)和新生血管指数(neovascularization index,NI)。利用HE染色进行病理分析。采用实时荧光定量PCR技术测定各组白细胞介素-2(interleukin-2,IL-2)、IL-10和血管内皮生长因子(vas-cular endothelial growth factor,VEGF)mR NA的表达。结果眼前节检查显示PK组大部分兔眼角膜水肿、混浊及大量新生血管,而DSEK组只有少量兔眼出现角膜混浊水肿。PK组13眼(92.9%)出现排斥反应,明显高于DSEK组的4眼(28.6%),差异有统计学意义(P<0.05)。病理组织切片显示,PK组单核细胞浸润明显高于DSEK组。实时荧光定量PCR检测结果显示,PK组IL-2、IL-10和VEGF mR NA的表达均明显高于DSEK组。结论 DSEK术后出现免疫排斥反应几率低,且比PK术后排斥反应程度弱,角膜内皮移植术是治疗角膜内皮疾病的一个理想选择。

ObjectiveTo analyze the outcome of descemet’s stripping with endothelial keratoplasty(DSEK)in high risk rabbit model and its immunological rejection.MethodsTogether28rabbits with corneal neovascularization beyond three quadrants were randomly divided into2groups(n=14)according to the surgical procedures,and they were penetrating keratoplasty(PK)and DSEK groups,with the right ones chosen as the experimental eyes in all rabbits.The corneal allograft condition(opacity,edema and neovascularization)was examined by the slit lamp biomicroscopy for8weeks,and rejection index(RI)and neovascularization index(NI)were recorded.The corneal sections were stained using hematoxylin eosin for histopathological evaluation.Then IL2,IL10and vascular endothelial growth factor(VEGF)mRNA expression were quantified by RT PCR.ResultsAnterior segment photographs showed corneal opacity,edema and neovascularization appeared in most rabbits of PK group,but few rabbits in the DSEK group did not have above complications.The corneal allograft rejection occurred in13eyes(92.9%)in PK group,which was significantly higher than that in DSEK group(4eyes,28.6%%)(P<0.05).Histology examination showed that more mononuclear cell infiltration appeared in PK group,which was more enhanced than that in DSEK group.Moreover,significantly up regulation expression of IL2,IL10and VEGF mRNA was observed in PK group when compared with DSEK group.ConclusionThese results suggest that corneal allograft rejection has less frequency and less severity after DSEK than after PK,suggesting endothelial keratoplasty could be an ideal strategy for the treatment of corneal endothelial disorders.