The hallmark lesions of age-related macular degeneration (AMD) are drusen and basal linear deposit which are lipid substances deposited in Bruch membrane or the compartment on the Bruch membrane. There is a prevailing hypothesis that lipid and its oxidized derivant deposited in retina may have important roles in the pathogenesis of AMD. Lipid oxidation products are toxic, may affect the adjacent cells, induce inflammation, and trigger neovascularization.7-ketocholestoral (7KCh), a naturally occurring oxidized form of cholesterol, had been found to be toxic to retinal cells and able to induce chronic inflammation, which may play a critical role in the development of AMD. However the precise mechanism remains to be elucidated. Thus we will make a brief review of 7KCh and its association with AMD.
Microparticles are small vesicles that are released by budding of the plasma membrane during cellular activation and apoptotic cell breakdown. A spectrum of cell types can release microparticles including endothelial cells, platelets, macrophages, lymphocytes and tumor cells. Biological effects of microparticles mainly include procoagulant activity, inhibition of inflammation and cancer progression. The present study shows that vitreous microparticles isolated from proliferative diabetic retinopathy (PDR) stimulated endothelial cell proliferation and increased new vessel formation, promoting the pathological neovascularization in PDR patients. Oxidative stress induces the formation of retina pigment epithelium-derived microparticles carrying membrane complement regulatory proteins, which is associated with drusen formation and age related macular degeneration. Microparticles from lymphocyte (LMP) play an important role in anti-angiogenesis by altering the gene expression pattern of angiogenesis-related factors in macrophages. Besides, LMP are important proapoptotic regulators for retinoblastoma cells through reduction of spleen tyrosine kinase expression and upregulation of the p53-p21 pathway which ultimately activates caspase-3. However, how to apply the microparticles in the prevention and treatment of retinal diseases is a major challenge, because the study of the microparticles in the fundus diseases is still limited. Further studies conducted would certainly enhance the application of microparticles in the fundus diseases.
ObjectiveTo evaluate the efficacy in the treatment of age-related macular degeneration (AMD) by bevacizumab versus ranibizumab. MethodsA computerized search was conducted in the Embase, Ovid, PubMed, China National Knowledge Infrastructure (CNKI), WanFang Data and VIP database of Chinese journal. Randomized controlled trials (RCTs) comparing bevacizumab with ranibizumab for AMD from inception to November, 2013 were collected. Methodology qualifies of studies were performed by experienced reviewers according to the inclusion and exclusion criteria. Further, the materials were analyzed with software RevMan 5.2.6. Visual acuity and central foveal thickness before and 3, 6, 12 months after treatment between the two treatment methods were compared. ResultsA total of 5 RCTs were included in this meta analysis, including 1954 patients (967 patients in the bevacizumab group, 987 eyes in the ranibizumab group). There was no difference in improving visual acuity after treatment between two groups [3 months: weighted mean difference (WMD)=0.32, 95% CI: -0.84 -1.49, P=0.59; 6 months: WMD=0.47, 95% CI: -0.67 -1.62, P=0.42; 12 months: WMD=0.84, 95% CI: -0.23 -1.90, P=0.12]. There was no difference in cutting down the central foveal thickness after treatment between two groups (3 months: WMD=6.21, 95% CI: -6.23-18.65, P=0.33; 6 months: WMD=4.06, 95% CI: -6.16-14.27, P=0.44; 12 months: WMD=-5.39, 95% CI: -14.41-3.63, P=0.24). ConclusionBevacizumab has equal efficacy to ranibizumab in the treatment of AMD.
Atrophic age-related macular degeneration (AMD) does not show obvious loss of visual function in the early stage, so it is not easy to be taken seriously. In the advanced stage, most of the patients suffered from macular area retinal map atrophy, which affected night vision and central vision. Drugs currently used in clinical or clinical trials to treat atrophic AMD include drugs for improving choroidal perfusion, reducing the accumulation of harmful substances, preventing oxidative stress injury, inhibiting inflammatory reactions, as well as neuroprotectants and lipid metabolism drugs. Stem cell transplantation for atrophic AMD is currently the most promising treatment. In theory, it is feasible to replace atrophic AMD with retinal photoreceptor cells and RPE cells derived from human stem cell differentiation. However, there are still many problems to be solved, such as how to improve the efficiency of directional differentiation of seed cells and how to ensure the safe and effective RPE cell transplantation and survival after transplantation. At present, several studies have found that multiple locus mutations are associated with atrophic AMD, so gene therapy also plays an important role in the development of the disease.
Objective To verifying the characteristics of optical coherence tomography(OCT) in exudative age-related macular degeneration (AMD). Methods The patients being investigated in this series included 16 cases (19 eyes) of exudative age-related macular degeneration diagnosed by FFA and OCT examinations, among them 4 cases (6 eyes) were examined with ICGA. The color photographs of ocular fundi, FFA, ICGA and OCT were investigated by contrasting each other. Results As compared with the FFA and ICGA examinations, the characteristic findings found in OCT in patients with exudative AMD in this series were as the following:①serous detachment of neurosensory epithelium in 11 eyes,②retinal hemorrhage in 2 eyes,③serous detachment of retinal pigment epithelium in 5 eyes,④hemorrhagic detachment of retinal pigment epithelium in 10 eyes,⑤disciform scar in 4 eyes,⑥fibrovascular pigment epithelial detachment and occult CNV in 12 eyes. Conclusion OCT can supply a comprehensive survey of exudative AMD, in making the diagnosis as an important complementary examination of FFA and ICGA. (Chin J Ocul Fundus Dis,2000,16:220-223)
Integrins is a family of multi-functional cell-adhesion molecules, heterodimeric receptors that connect extracellular matrix to actin cytoskeleton in the cell cortex, thus regulating various physiological and pathological processes. Risuteganib (Luminate®) is a novel broad-spectrum integrin inhibitor. Based on multiple biological functions of anti-angiogenesis, vitreolysis, and neuroprotection, risuteganib is hopeful in treating several fundus diseases such as diabetic macular edema, vitreomacular traction, and non-exudative age-related macular degeneration. By far, risuteganib has successfully met the endpoints for three phase 2 studies and is preparing to enter the phase 3 of diabetic macular edema clinical trials. Overall the risuteganib is safe with no serious ocular or systemic adverse events. Given the unique mechanism of action and longer duration of efficacy, intravitreal injection of risuteganib has the potential to serve as a primary therapy, or adjunctive therapy to anti-VEGF agents.
For the past few years, artificial intelligence (AI) technology has developed rapidly and has become frontier and hot topics in medical research. While the deep learning algorithm based on artificial neural networks is one of the most representative tool in this field. The advancement of ophthalmology is inseparable from a variety of imaging methods, and the pronounced convenience and high efficiency endow AI technology with promising applications in screening, diagnosis and follow-up of ophthalmic diseases. At present, related research on ophthalmologic AI technology has been carried out in terms of multiple diseases and multimodality. Many valuable results have been reported aiming at several common diseases of ophthalmology. It should be emphasized that ophthalmic AI products are still faced with some problems towards practical application. The regulatory mechanism and evaluation criteria have not yet integrated as a standardized system. There are still a number of aspects to be optimized before large-scale distribution in clinical utility. Briefly, the innovation of ophthalmologic AI technology is attributed to multidisciplinary cooperation, which is of great significance to China's public health undertakings, and will be bound to benefit patients in future clinical practice.
Objective To investigate the clinical features of polypoidal choroidal vasculopathy. Methods The clinical manifestations and the findings of fundus fluorescein angiography (FFA) and indocyanine green angiography (ICGA) of 7 eyes in 6 patients with polypoidal choroidal vasculopathy were analyzed retrospec tively.Results The ophthalmoscopic examination of PCV in this series of patients revealed orange-red lesions mainly in macular region in early stage, and then hemorrhage, exudation, edema, serous and (or) hemorrhagic detachment of retinal pigment epithelium in affected portions in advanced stage, and retinal and choroidal atrophy in late stage. FFA discovered the vascular dilation at the border of the choroidal vascular network in 1 eye, dotted hyperfluorescence in 6 eyes, and patches of hyperfluorescence in late phase. ICGA disclosed a vascular branching network in choroid with polypoid pattern of the terminal path of the vessels of network in early phase in 5 eyes, and the typical dotted or clustered polypoidal hyperfluorescence in 7 eyes in late phase.Conclusion The characteristic findings of FFA and ICGA are very diagnostic for PCV. (Chin J Ocul Fundus Dis，2003，19：269-332)
Objective To investigate the disease-causing gene of Stargardt disease. Method Fifteen patients with Stargardt disease were analyzed with 11 primers of the 11 exons of ABCR gene by using PCR-SSCP and DNA direct sequencing techniques. Results Three newly detected disease-causing mutations were found. Among those mutations, one is a frameshift mutation and others are single base transition. Conclusion This research confirmed that ABCR gene is associated with Stargardt disease, and 3 new mutations of ABCR gene were found. (Chin J Ocul Fundus Dis,2000,16:240-243)
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.