Netland P A, Ye H, Streeten B W, Hernandez M R
Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, MA 02114, USA.
Ophthalmology. 1995 Jun;102(6):878-86. doi: 10.1016/s0161-6420(95)30939-6.
Pseudoexfoliation syndrome is characterized by the presence of glycoprotein fibers in ocular and extraocular tissues, and often is associated with glaucoma. Pseudoexfoliation material may be associated closely with elastic microfibrillar-associated glycoprotein as well as elastin.
Four optic nerve heads of two patients with pseudoexfoliation syndrome and glaucoma were examined using electron microscopy and immunogold detection of elastin. Optic nerve heads from healthy age-matched individuals and patients with primary open-angle glaucoma were used for comparisons.
In all eyes with pseudoexfoliation and glaucoma, there was marked and widespread elastosis in the connective tissue of the lamina cribrosa. Elastotic fibers appeared as large and irregular aggregates of electron-dense material labeled with anti-elastin antibody. Abundant microfibrils were interspersed in the elastotic aggregates, whereas no typical pseudoexfoliation fibers were observed. In contrast, there were less elastotic fibers in the lamina cribrosa from patients with primary open-angle glaucoma compared with pseudoexfoliation glaucoma. Other changes of extracellular matrix were similar to those observed in primary open-angle glaucoma: decreases in collagen fiber density, presence of basement membranes not associated with cell surfaces, and abundant bundles of microfibrils not labeled with elastin antibody. The elastic fibers appeared normal in other locations within the optic nerves of patients with pseudoexfoliation glaucoma, including in the pial septa and blood vessels of the retrolaminar myelinated optic nerve.
The authors' findings demonstrate marked and site-specific elastosis in the lamina cribrosa of patients with pseudoexfoliation syndrome with glaucoma, suggesting an abnormal regulation of elastin synthesis and/or degradation in the optic nerve of patients with this disease.
假性剥脱综合征的特征是眼内和眼外组织中存在糖蛋白纤维，且常与青光眼相关。假性剥脱物质可能与弹性微原纤维相关糖蛋白以及弹性蛋白密切相关。
使用电子显微镜和弹性蛋白免疫金检测法对两名患有假性剥脱综合征和青光眼患者的四个视神经乳头进行检查。将年龄匹配的健康个体以及原发性开角型青光眼患者的视神经乳头用作对照。
在所有患有假性剥脱和青光眼的眼中，筛板结缔组织中均存在明显且广泛的弹性组织变性。弹性变性纤维表现为被抗弹性蛋白抗体标记的电子致密物质的大而不规则聚集体。大量微原纤维散布于弹性变性聚集体中，而未观察到典型的假性剥脱纤维。相比之下，原发性开角型青光眼患者筛板中的弹性变性纤维少于假性剥脱性青光眼患者。细胞外基质的其他变化与原发性开角型青光眼所见相似：胶原纤维密度降低、存在与细胞表面无关的基底膜以及大量未被弹性蛋白抗体标记的微原纤维束。在假性剥脱性青光眼患者视神经的其他部位，包括软脑膜隔和视网膜后有髓视神经的血管中，弹性纤维看起来正常。
作者的研究结果表明，患有假性剥脱综合征合并青光眼的患者筛板中存在明显且位点特异性的弹性组织变性，提示该疾病患者视神经中弹性蛋白合成和/或降解存在异常调节。
