青光眼是一组以特征性视神经萎缩和视野缺损为共同特征的疾病,病理性眼压增高是其主要危险因素。视网膜神经节细胞(retinal ganglion cells,RGCs)凋亡及其轴突丢失是青光眼的主要病理特征。细胞外基质(extracellularmatrix,ECM)含量和成分的变化对小梁网构型、视乳头筛板结构、RGCs凋亡起着决定性作用。青光眼患者小梁网及房水中转化生长因子-β2(transforming growth factor-β2,TGF-β2)增加,引起ECM分泌增加和堆积导致眼压升高;高眼压引起视神经乳头ECM成分的改变,引起神经营养因子剥夺,导致RGCs凋亡;同时,高眼压引起视网膜基质金属蛋白酶类-9(matrix metalloproteinase-9,MMPs-9)活性增加,层连黏蛋白的减少又将导致RGCs凋亡的增加。因此,研究ECM和青光眼的关系至关重要,可能为原发性开角型青光眼发病机制及治疗提供新的方向。
Glaucoma is characterized by optic atrophy and visual field defect.The pathological elevated intraocular pressure is the leading risk factor for glaucoma.The pathological characteristic of glaucoma is apoptosis of retinal ganglion cells(RGCs) and their axon loss.Changes of the amounts and compositions of the extracellular matrix(ECM) play a crucial role in the structure of trabecular meshwork,lamina cribrose of opitic nerve head and the apoptosis of RGCs.The expression of transforming growth factor-β2(TGF-β2)increases in trabecular meshwork and aqueous humor for glaucomatic patients,which leads to elevated intraocular pressure by secretion and accumulation of ECM.Elevated intraocular pressure causes changes in ECM of optic nerve head and retina,resulting in blocked transport of neurotrophins,the high level of matrix metalloproteinase(MMPs)-9 and low level of laminin respectively,which eventually lead to the apoptosis of RGCs.Therefore,it is important to understand the relationship between ECM and glaucoma,which may provide a new direction for glaucomatous pathogenesis and therapy.