前部增生性玻璃体视网膜病变引起慢性低眼压发病机制的探讨

An ivestigation on pathogenesis of chronic hypotony following anterior proliferative vitreoretinopathy

目的 探讨前部增生性玻璃体视网膜病变 (anterior proliferative vitreoretinopathy,a PVR)病理状态下低眼压的发生、发展及转归 ,为防治 a PVR引起的慢性低眼压提供理论依据。 方法 利用培养的同种兔皮肤成纤维细胞制作 a PVR引起慢性低眼压的动物模型 ,于术前及术后不同时间点分别观测眼压(intraocular pressure,IOP) ,行超声生物显微镜 (ultrasound biomicroscopy,U BM)检查 ,并做病理、电镜观察。 结果 术后 1周、2周、4周、8周实验组平均眼压明显低于对照组 (P<0 .0 1)。 UBM显示术后 4周实验组虹膜后睫状体内侧条形回声 ,术后 4周及 8周实验组周边视网膜牵引性脱离。光镜检查发现实验组 4周及 8周睫状体无色素上皮萎缩、缺失。电镜检查发现实验组术后 4周和 8周睫状体无色素上皮线粒体明显减少 ,细胞内空泡。 结论 在 a PVR病理状态下 ,睫状膜的增生和收缩引起对睫状上皮的牵拉 ,造成睫状体无色素上皮萎缩 ,可能是引起慢性低眼压的主要原因。

Objective To investigate the occurrence, progress and conversion of hypotony in anterior proliferative vitreoretinopathy (aPVR), and to provide knowledge about how to prevent and treat it. Methods Animal models of chronic hypotony by aPVR were made with cultured homologous dermal fibroblasts on pigmented rabbits. The intraocular pressure (IOP) and ultrasound biomicroscopy(UBM) examination were taken preoperatively and on days 7,14, 28 and 56 postoperatively. Rabbits were killed on days 14, 28 or 56 postoperatively, prepared for histology and ultrastructure examination. Results The average IOP of experimental group was lower than that of control group on days 7,14,28 and 56 significantly (P<0.01).UBM demonstrated that trip like echo emerged in front of ciliary body four weeks postoperatively, and tractional retinal detachment was found four weeks and eight weeks postoperatively in experimental group. Microscopic examination showed atrophy or absence of the non pigmented ciliary epithelium on days 28 and 56 postoperatively in experimental group. Electronic microscopy showed that the amount of mitochondrions decreased and there were many vacuoles in the non pigmented ciliary epithelium in experimental group four and eight weeks postoperatively. Conclusions Atrophic change of the non pigmented epithelium due to dragging effect of the ciliary body from the epiciliary membrane in aPVR might be the main cause of hypotony.