原发性开角型青光眼中枢视觉通路的改变

原发性开角型青光眼是临床上常见的一种不可逆性致盲眼病,对于青光眼所造成的视网膜神经节细胞水平及视神经水平的损害已得到广泛研究.最近研究表明,青光眼患者的上行视路部分,如外侧膝状体及枕叶视皮质等,存在损伤,提示青光眼可能同时也是一种中枢神经退行性疾病,早期对青光眼进行视神经保护治疗有助于减缓视神经节细胞的凋亡并阻止视功能的进一步损害.本文将从青光眼中枢损伤的发病机制、临床诊断及青光眼视神经保护治疗方面的研究进展进行综述,并对青光眼的研究前景进行展望.     

青光眼视神经损伤机制的研究进展

青光眼是目前全球范围内致盲性最高的疾病之一,是以进行性视网膜神经节细胞丧失、不可逆的视野损害等病理性改变为特征,最终导致视神经萎缩及视功能丧失的疾病。目前青光眼的发病机制并不完全清楚,其中视神经损伤的机制有多种学说,包括眼压因素及非眼压因素,非眼压因素包括血管因素、免疫作用、远端轴突病变、氧化应激作用、细胞因子的变化及自噬等机制。本文综述了有关青光眼视神经损伤机制的研究进展,为进一步研究青光眼视神经病变提供依据。     

青光眼的中枢损伤

青光眼性损伤的形态学特征及病理机制 ,在视网膜节细胞水平及视神经水平已得到广泛研究 ;最近研究表明 ,青光眼对外侧膝状体、视皮质等中枢视路也存在相应损伤 ,并且提示青光眼的中枢损伤可能参与视功能状态的进一步恶化。我们对近年来青光眼中枢损伤的病理形态学及病理机制研究作一综述。     

免疫与青光眼

青光眼是不可逆盲的主要原因之一,是视神经的慢性退行性病变.视网膜神经节细胞（RGCs）凋亡和视神经纤维进行性丢失可导致青光眼患者视神经结构和视功能的损害.越来越多的临床和实验研究表明,免疫系统参与青光眼的神经变性过程.青光眼患者视神经变性中涉及免疫机制及免疫系统相关细胞的相互作用,包括眼免疫赦免环境的破坏、胶质细胞的异常激活、T细胞免疫的异常、Th1/Th2免疫失衡、自身抗原的产生、补体通路的激活、氧化应激反应、衰老等免疫因素及氧化应激放大的初始压力损伤,这些因素均可使青光眼视神经进一步损害.就眼的保护性免疫和免疫异常与青光眼的研究进展进行综述.     

青光眼视神经保护的免疫学途径

导致青光眼视功能损害的病理基础是视网膜神经节细胞进行性凋亡和丧失。目前对视网膜神经节细胞损伤和保护的治疗研究已取得一些进展,如:采用可溶性抗原诱导免疫耐受以避免对破坏性自身抗原应答的诱导;在避免自身免疫性疾病基础上,发挥T细胞神经保护性免疫反应的治疗作用;利用谷氨酸受体拮抗剂、钙离子通道阻滞剂、免疫抑制剂等非特异性治疗,减轻和预防视网膜神经节细胞的不可逆性损伤。本文就视网膜神经节细胞的凋亡、青光眼视神经损害的免疫学机制及视神经保护的免疫学途径进行综述,并从自身抗原、抗原多肽、免疫抑制剂等方面探讨视神经保护在免疫学的可能途径。     

青光眼视神经保护的免疫学途径

导致青光眼视功能损害的病理基础是视网膜神经节细胞进行性凋亡和丧失。目前对视网膜神经节细胞损伤和保护的治疗研究已取得一些进展，如：采用可溶性抗原诱导免疫耐受以避免对破坏性自身抗原应答的诱导；在避免自身免疫性疾病基础上，发挥T细胞神经保护性免疫反应的治疗作用；利用谷氨酸受体拮抗剂、钙离子通道阻滞剂、免疫抑制剂等非特异性治疗，减轻和预防视网膜神经节细胞的不可逆性损伤。本就视网膜神经节细胞的凋亡、青光眼视神经损害的免疫学机制及视神经保护的免疫学途径进行综述，并从自身抗原、抗原多肽、免疫抑制剂等方面探讨视神经保护在免疫学的可能途径。     

青光眼的视网膜神经节细胞损伤及其保护

高眼压一直被认为是引起青光眼视神经损害的重要机制，但是临床发现部分青光眼患者即使眼压得到很好的控制也不能阻止视神经的进一步损害。青光眼造成的视神经萎缩不仅是高眼压导致的视神经受压萎缩，更多的研究结果表明青光眼的视神经改变是一种视神经病变，原因有多种，但均表现为视神经节细胞的死亡。这一视神经节细胞的死亡过程是一种缓慢的凋亡过程，具体可分为两个阶段：第一阶段是缺血、缺氧造成的细胞损害；第二阶段是受损的退变细胞释放有害物质引起基质的改变和损伤。     

青光眼视神经保护的研究进展

视网膜神经节细胞死亡是青光眼视神经损伤的最终共同通路,阻断视神经损伤通路和增强视神经存活机制的方法称为视神经保护。目前这一研究领域主要包括抗凋亡途径,促红细胞生成素,谷氨酸拮抗剂,钙离子拮抗剂,一氧化氮合酶抑制剂,神经营养因子,自身保护性免疫,抗青光眼药物等方面。将来视神经保护将成为一种重要的青光眼辅助治疗措施     

视网膜神经胶质细胞与青光眼

青光眼视神经病变以进行性的视网膜神经节细胞丧失和相应的视功能损害为特征.导致青光眼视神经病变的病理生理机制尚不明确.在中枢神经系统,神经胶质细胞参与了神经元在受到机械、缺血、缺氧等损伤后的病理变化过程.胶质细胞参与青光眼视神经病变的机制复杂多样,但部分机制与中枢神经系统相似.本文就视网膜神经胶质细胞的生理功能、动物青光眼模型建立后胶质细胞的反应以及针对胶质细胞的青光眼视神经保护治疗手段做一综述.     

免疫系统与青光眼

青光眼是一组以视神经凹陷性萎缩和视野缺陷为共同特征的疾病,病理性眼压增高是其主要危险因素。多种因素决定了青光眼视神经节细胞的最后结局。而免疫因素在青光眼的视网膜视神经损害中所起的作用应该是双重的。所以探明免疫系统在青光眼损伤修复中的作用,对青光眼的治疗具有重要的意义。     

原发性青光眼视神经损害的发生机制

关于原发性青光眼的发病机制,目前有许多学说,但每种学说都不能完全说明青光眼视神经损害的具体机制。综合分析发现,每个正常人或青光眼患者身上都具有致视神经损害因素和抗视神经损害因素,青光眼发生与否是这两种因素相斗争的结果。眼压虽然不是青光眼视神经损害的唯一因素,但仍然是青光眼最主要和最稳定的危险因素。另外,血循环因素和免疫因素也是导致青光眼视神经损害的重要原因。本文综合分析了近年来有关原发性青光眼视神经损害机制的研究,并以独特的视角分析了眼压对青光眼视神经损害的具体机制。     

Is there a role for the immune system in glaucomatous optic neuropathy?

Glaucoma and immunity are not traditionally perceived as being causally related. Recently, however, compelling observations have provided insight into a potential role for the immune system in the development of glaucomatous optic neuropathy. In this article, it is proposed that the role of the immune system in glaucoma is two-fold. In some patients, there is evidence that an autoimmune mechanism may be responsible for eliciting damage to the optic nerve, resulting in glaucomatous injury. Autoimmune damage to the optic nerve may occur directly by autoantibodies, or indirectly by way of a "mimicked" autoimmune response to a sensitizing antigen which, in turn, injuries retinal ganglion cells. We suggest that autoimmune-mediated glaucoma injury occurs most often, but not exclusively, in patients in whom the intraocular pressure has never been found to be elevated. A second role of the immune system in glaucoma is likely one of surveillance, in which signal pathways of the immune system regulate cell death in response to conditions that stress retinal neurons in glaucoma. These might include mechanical stress from high intraocular pressure, ischemia, excessive excitatory amino acids, or toxic products resulting from excessive nitric oxide synthase production in either neurons or glial fibers that surround the optic nerve as it exits the eye. In these cases, we propose that the immune system acts as an "arbiter" to help determine whether a neuronal cell will ultimately survive, or succumb to, those stressors that are perceived as injurious. It is conceivable that such surveillance and cell death regulation by the immune system is important in determining the fate of retinal neurons in both the more common "high-pressure" forms of glaucoma, such as primary open-angle glaucoma, and in cases in which the intraocular pressure appears within normal range.     

Research progress of stem cells on glaucomatous optic nerve injury

Glaucoma, the second leading cause of blindness, is an irreversible optic neuropathy. The mechanism of optic nerve injury caused by glaucoma is undefined at present. There is no effective treatment method for the injury. Stem cells have the capacity of self-renewal and differentiation. These two features have made them become the research focus on improving the injury at present. This paper reviews the application progress on different types of stem cells therapy for optic nerve injury caused by glaucoma.     

小胶质细胞极化在青光眼视神经损伤发病机制及治疗中的研究进展

青光眼是多因素介导的以视网膜神经节细胞凋亡、视神经萎缩和视野缺损为特征的神经退行性眼病,发病机制尚不明确.小胶质细胞是视网膜内常驻的免疫细胞,它可分为经典激活M1型和替代激活M2型,随着眼压改变以及视网膜神经节细胞损伤修复过程的进展,小胶质细胞的极性呈现动态变化,可产生多种具有神经毒性或神经保护作用的细胞因子.近年来,...     

免疫系统调节在青光眼性视神经病变中的作用

青光眼是一种以进行性视网膜神经节细胞及其轴突丧失为特征且伴有视野敏感度降低的慢性视神经变性疾病。随着近年来免疫学研究的深入,免疫系统调节在青光眼性视神经保护中的作用越来越引起了研究者的高度重视。当机体免疫系统出现异常调节时,自身免疫反应和应激介导的免疫反应也将导致视神经的退行性改变。全面、系统地了解免疫系统在青光眼视神经病变中的作用,对于确立有效的视神经保护策略具有重要的指导意义。因此,有必要就免疫系统在青光眼性视神经病变中的作用予以综述。     

Neuronal death in glaucoma

Glaucoma is recognized to have its major detrimental effect upon the eye by killing retinal ganglion cells. The process of cell death appears to be initiated at the optic nerve head, though other sites of injury are possible but unsubstantiated. At present the injury at the nerve head seems related to the level of the eye pressure, but its detailed mechanism is as yet unexplained. There is a greater loss of ganglion cells from some areas of the eye, and this feature of glaucoma seems related to the regional structure of the supporting connective tissues of the optic nerve head. Larger retinal ganglion cells have been consistently shown to have somewhat greater susceptibility to injury in glaucoma, though all cells are injured, even early in the process. Ganglion cells die by apoptosis in human and experimental glaucoma, opening several potential areas for future therapies to protect them from dying. Neurotrophin deprivation is one possible cause of cell death and replacement therapy is a potential approach to treatment.     

Glial cell and glaucomatous optic neuropathy

Glaucomatous optic neuropathy is a chronic disease accompanied by visual field loss, cupping of optic nerve head, and apoptosis of retinal ganglion cells (RGCs). The mechanism of glaucomatous optic neuropathy is unknown but glial cells play an important role in glaucomatous optic nerve damage and the repair process. We review the role of glial cells in the remodeling of optic nerve head, apoptosis of RGCs and immune reactions in glaucoma.     

干细胞治疗青光眼的研究进展

青光眼是一类不可逆性视神经变性和视野缺损的疾病,青光眼导致视神经损伤的机制目前尚未明确,临床上对青光眼的治疗一直未取得良好的效果.干细胞具有自我增殖和分化的能力.近年来随着对干细胞研究的深入,人类利用干细胞治疗青光眼成为可能.青光眼干细胞移植分两大类:一是基于小梁网的干细胞替代治疗,另一类是视网膜神经节细胞的替代治疗.本文就干细胞治疗青光眼的研究进展进行综述.