Age-related macular degeneration (AMD) is a fundus disease characterized by degeneration of retinal photoreceptor cells, RPE cells and choroidal capillaries. The pathogenesis is not clear and there is no effective treatment. Cell therapies can slow or reverse the vision loss of AMD in animal models, which include implantation of bone marrow mesenchymal stem cells, pluripotent stem cells, RPE cells into the subretinal cavity. Therefore, cell therapy is a promising strategy for the treatment of AMD.
Dysregulation and activation of immune processes are important in age-related macular degeneration (AMD) pathogenesis. The single nucleotide polymorphism of complement factor H is widely recognized as a risk factor to AMD. Over-activation of nod-like receptor3 and polymorphism of Toll-Like Receptor 3 also associated with AMD. Except for innate immune processes, adaptive immunity also play a critical role in AMD, a growing body of evidence supports that auto-antibodies and T cells are related with AMD. Additionally A2E and lipid oxidation byproducts might also have a role in AMD pathogenesis.
Objective To observe the clinical features of polypoidal choroidal vasculopathy (PCV) in Chinese patients.Methods Nine cases (9 eyes ) were examined with fundus examination, fundus fluorescein angiography (FFA) and indocyanine green angiography angiography (ICGA).Results FFA and ICGA showed the branching vascular networks (7 cases) and polyplike dilation at terminals of branches (9 cases), which mainly located in macular area (8 cases) and in peripapillary area (1 case), and which accompanied hemorrhagic or serous pigment epithelial detachment in 7 cases,and 4 of 7 cases had a significant horizontal black-white damarcation line. It definitely differed from fine choroidal neovascularization (CNV).Conclusion PCV in Chinese patients has the cardinal clinical features, i.e., polyplike lesions located mainly in macular area and most cases accompanied by hemorrhagic or serous pigment epithelium detachment. (Chin J Ocul Fundus Dis，2003，19：269-332)
Replacement of diseased retinal pigment epithelium (RPE) cells with healthy RPE cells by transplantation is one option to treat several retinal degenerative diseases including age-related macular degeneration, which are caused by RPE loss and dysfunction. A cellular scaffold as a carrier for transplanted cells, may hold immense promise for facilitating cell migration and promoting the integration of RPE cells into the host environment. Scaffolds can be prepared from a variety of natural and synthetic materials. Strategies, such as surface modification and structure adjustment, can improve the biomimetic properties of the scaffolds, optimize cell attachment and cellular function following transplantation and lay a foundation of clinical application in the future.
Age-related macular degeneration (AMD) is an age-related degenerative disease with complex pathogenesis, whose initial lesion is accompanied with immune inflammatory response. Amyloid beta (Aβ), a small-molecule protein generated by the hydrolysis of amyloid precursor protein, as the main component, is involved in the formation of drusen, which serves as the early characteristic of AMD. In the local inflammatory response of AMD, Aβ is an important pathological deposit, promoting the proliferation and differentiation of macrophages as well as changing their morphology to accelerate the progression of AMD. In addition, Aβ can also regulate immune molecules and the complement system by activating inflammatory pathways, thus mediating chronic retinal inflammation and promoting the course of AMD. However, since AMD is not caused by inflammation alone, only the immunosuppression may not be effective in inhibiting the course of AMD, and thus the future development is to rebalance the disordered immune system in AMD patients eyes.
Objective
To study the ultrasonographic manifestation character of age-related macular degeneration (AMD).
Methods
The ultrasonographic manifestation of thirty-five cases (38 eyes) of AMD diagnosed by fundus fluorescein angiography (FFA) with positive findings of ultrasonic B-scan were analysed．
Results
The ultrasonic appearance of interlamellar transaudient cleft were found in 26 eyes, in which FFA appearance were serous detachment of pigment epithelium and subretinal neovascularization, 5 of them associated with small excavation of choroid, 4 of them associated with b echo belt at the posterior edge of the interlamellar transaudient cleft in which the FFA appearance was extensive subretinal neovascularization．In another 4 eyes with choroidal hematoma under FFA revealed thin echo light spots in the interlamellar transaudient cleft． There was scar-staining in the other 8 eyes in which the ultrasonic appearance showed an unequal thickening of the ocular wall in the posterior pole,unequal echo of interior edge and irregular inner echo．
Conclusion
The main ultrasonographic manifestation of AMD is the presence of interlamellar transaudient cleft in the thickened ocular wall.
(Chin J Ocul Fundus Dis,2000,16:228-230)
Based on the pathogenic mechanisms of age-related macular degeneration (AMD), tremendous preclinical and clinical trials have demonstrated that cell transplantation which aim to replace impaired retinal pigment epithelium (RPE) with healthy RPE cells is a promising approach to treat AMD. So far, choices of cell sources mainly are autologous RPE, iris pigment epithelium, fetal RPE, human embryonic stem cell-derived RPE and human induced pluripotent stem cell-derived RPE, and some of them are undergoing clinical researches. Grafting manners in cell-based therapies are various including RPE sheet or RPE-choroid complex transplantation, RPE cell suspension injection, and RPE sheet transplantation with scaffolds. This review is limited to cell-based therapies for RPE that damaged first in the progress of AMD and focus on recent advances in cell sources, transplantation methods, preclinical and clinical trials, and the obstacles that must be overcome.
Pyroptosis is an inflammatory form of programmed cell death, including canonical and non-canonical pyroptosis pathway. Studies on pyroptosis have been reported in a variety of retinal diseases, but they are more focused on common diseases such as diabetic retinopathy and age-related macular degeneration. Many retinal diseases are difficult to treat because of the complexity of their etiology and pathogenesis. The discovery of pyroptosis has brought new content to the pathogenesis of these diseases, and also pointed a new direction for the treatment. Pyroptosis does not occur independently, and it is related to apoptosis and autophagy, but the specific mechanism is not clear. However, the most important biomolecule in the process of pyroptosis have been basically determined, and some methods can be used to interfere with pyroptosis, which has obtained preliminary achievement, suggesting that inhibition of pyroptosis may be a new direction for the treatment of retinal diseases and has broad research prospects.
