Vinores S A, Küchle M, Derevjanik N L, Henderer J D, Mahlow J, Green W R, Campochiaro P A
Wilmer Ophthalmologic Institute, Johns Hopkins University, School of Medicine, Baltimore, MD 21287-9289, USA.
Histol Histopathol. 1995 Oct;10(4):913-23.
Macular edema can contribute to visual loss in the retinitis pigmentosa (RP), but the sites and mechanism of blood-retinal barrier (BRB) breakdown leading to macular edema are not known. An understanding of the mechanisms involved could lead to the design of effective pharmacologic therapy to prevent or minimize macular edema in RP. To investigate this problem, immunohistochemical staining for albumin was performed on paraffin sections of 22 normal and 29 RP-affected eyes. Specimens were graded for extent of albumin extravasation in different regions of the retina, optic nerve head, ciliary body, and iris. Electron microscopic immunocytochemical staining for albumin was performed on an additional 6 normal and 9 RP-affected eyes. Two-thirds of the eyes from patients with RP and no other ocular disorders demonstrated extravascular albumin in the inner portion of the posterior retina. This was evident even in the absence of cystoid macular edema (CME), but eyes that had CME showed extensive BRB failure. In some cases, passage of albumin from the choroid to the retina was prevented even in the absence of the retinal pigment epithelium (RPE). Electron microscopic immunocytochemistry revealed that albumin permeated retinal vascular endothelial cells and RPE cells that showed degenerative changes in RP.
黄斑水肿可导致视网膜色素变性（RP）患者视力丧失，但导致黄斑水肿的血视网膜屏障（BRB）破坏的部位和机制尚不清楚。了解其中涉及的机制可能会有助于设计有效的药物疗法，以预防或减少RP患者的黄斑水肿。为了研究这个问题，对22只正常眼睛和29只RP患眼的石蜡切片进行了白蛋白免疫组化染色。对视网膜、视神经乳头、睫状体和虹膜不同区域的白蛋白外渗程度进行了标本分级。对另外6只正常眼睛和9只RP患眼进行了白蛋白的电子显微镜免疫细胞化学染色。三分之二没有其他眼部疾病的RP患者的眼睛在视网膜后部内侧显示血管外白蛋白。即使在没有黄斑囊样水肿（CME）的情况下也是如此，但患有CME的眼睛显示出广泛的BRB破坏。在某些情况下，即使没有视网膜色素上皮（RPE），白蛋白也无法从脉络膜进入视网膜。电子显微镜免疫细胞化学显示，白蛋白渗透到RP中出现退行性变化的视网膜血管内皮细胞和RPE细胞中。
