Lee Ji Woong, Park Won Young, Kim Eun Ah, Yun Il Han
Department of Ophthalmology, Pusan National University Hospital, Busan, Korea.
Ophthalmic Res. 2014;51(3):129-39. doi: 10.1159/000357097. Epub 2014 Feb 5.
To investigate the histopathology of the fibrous capsule around Ahmed glaucoma valves (AGVs) implanted with adjunctive amniotic membranes in rabbits.
AGV implantation with or without adjunctive amniotic membrane was performed in a single eye of 20 albino rabbits. The upper surface of the AGV body was covered with amniotic membrane in the study group. After 2 months, histology was used to compare the thickness and characteristics of the fibrous capsule, transdifferentiation of myofibroblasts, and density of blood vessels and leukocytes between the study and control groups.
The fibrous capsule along the roof of the bleb was composed of compact collagen fibers with minimal vascularization in the control group. In contrast, in the study group, the fibrous capsule was looser and had a more disorganized collagen architecture. The thickness of the fibrous capsule and the myofibroblast layer was significantly thinner in the study group than in the control group (p < 0.001). The number of CD31-positive blood vessels did not differ between the two groups (p = 0.235). CD45-positive inflammatory cells were more frequently observed in the study group than the control group (p = 0.001). The groups did not differ in the thickness of the fibrous capsule or myofibroblast layer, or the density of blood vessels and leukocytes along the floor of the bleb.
Adjunctive amniotic membranes could reduce the risk of encapsulation and aqueous outflow resistance by altering the tissue response to implanted AGVs and subsequent formation of a loose thin capsule.
研究在兔眼植入艾哈迈德青光眼引流阀（AGV）并辅助羊膜后的纤维囊组织病理学。
对20只白化兔的单眼进行有无辅助羊膜的AGV植入。研究组中AGV体的上表面覆盖有羊膜。2个月后，采用组织学方法比较研究组和对照组之间纤维囊的厚度和特征、肌成纤维细胞的转分化以及血管和白细胞密度。
对照组中，沿滤过泡顶部的纤维囊由紧密的胶原纤维组成，血管化程度最低。相比之下，研究组的纤维囊较疏松，胶原结构更紊乱。研究组纤维囊和肌成纤维细胞层的厚度明显薄于对照组（p<0.001）。两组间CD31阳性血管数量无差异（p = 0.235）。研究组中CD45阳性炎性细胞的观察频率高于对照组（p = 0.001）。两组在滤过泡底部的纤维囊或肌成纤维细胞层厚度、血管和白细胞密度方面无差异。
辅助羊膜可通过改变组织对植入AGV的反应以及随后形成疏松薄囊，降低包裹风险和房水流出阻力。
