Objective To investigate the serum levels of vitamin B12 and folic acid (FA) of exudative agerelated macular degeneration (AMD).Methods A total of 84 patients with exudative AMD（AMD group）and 78 patients with non-exudative AMD （control group） diagnosed at Xijing Hospital between June 2008 and September 2009 were assessed in this study. Serum vitamin B12 and FA levels were measured by chemiluminescence immunoassay. The statistical information of epidemiology and risk factors exposure histories were collected and compared.Results AMD group had significantly lower serum vitamin B12 levels ［（247.51plusmn;93.92）ng/ml］ compared with the control group ［（312.52plusmn;143.08） ng/ml］，the difference was statistical significance (t=5.013, P＜0.001). Serum FA levels in AMD group ［（5.64plusmn;3.72）ng/ml］ were slightly lower than the control group ［（10.14plusmn;4.48） ng/ml］, the difference was not statistical significance (t=0.780, P=0.437).Conclusion People with lower serum vitamin B12have higher risk of exudative AMD. Low levels of serum vitamin B12 may relate with the occurrence of exudative AMD.
Purpose To detect whether a 3243 point mutation existed in age-related macular degeneration (AMD). MethodsTwenty-six cases of wet form AMD patients, ten cases of dry form AMD patients were selected,and compared with twenty nomal controls. After collecting anti-coagulated blood samples, total cellular DNA were extracted and purified. Using polymerase chain reaction and restriction fragment long polymorphism techniques, the mtDNA Ararr;G point mutation at position 3243 were detected. Results After cleaveded by restriction endonuclease Apa I, a 294 bp fragment remained only in all detected DNA samples including twenty-six wet form AMD, and ten dry form AMD. No any other fragment appeared. The result showed that there was no Ararr;G mutation at position 3243 found in AMD. Conclusion It is suggested that mtDNA 3243 point mutation due to maternal inheritance might be not concerned with both wet form AMD and dry form AMD. (Chin J Ocul Fundus Dis,2000,16:231-232)
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.
ObjectiveTo study the prevalence of age-related macular degeneration (AMD) in the population aged 50 and over in Qidong County of Jangsu Province. Methods3644 individuals from 4 villages were randomly selected by clustering sampling method, according to the household registration information and door to door visits. Visual acuity was measured by modified Bailey-Lovie E logMAR chart. The examination of eyelids, cornea, lens and fundus were also carried out. The diagnosis of AMD was made according to the clinical hierarchy system by Age-Related Eye Diseases Study. χ2 test was used to analyze the prevalence of AMD and its related factors. ResultsAmong 3644 selected individuals, 2985 individuals received examination with a participating rate of 81.92%. In total 97 patients (136 eyes) had AMD with a prevalence rate of 3.25%. Among them, 71 patients (105 eyes) had early stage of AMD (2.38%); 26 patients (31 eyes) had late stage of AMD (0.87%). In these late stage patients, there were 9 patients (13 eyes) of exudative lesions (0.30%). There were 32 male (3.11%) and 65 female (3.32%) patients. There was no statistically significant difference between male and female prevalence (χ2=0.29, P > 0.05). Correlation analysis results showed that the long-term smoking (χ2=15.19) and heart cerebrovascular disease (χ2=81.50) was associated with AMD (P < 0.05). ConclusionsThe prevalence rate of AMD is 3.25% in the residents aged 50 and above in the rural area of Qidong County, Jangsu Province. Long-term smoking, high blood pressure and cardiovascular disease are the risk factors of AMD.
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.
Macular pigment (MP) is composed of lutein, zeaxanthin, and meso-zeaxanthin, which accumulate mainly at the macula. MP has antioxidant function and can filtering blue wave. Measurement of MP is about its optical density, that is, macular pigment optical density (MPOD). This review summarizes the function and clinical use of MP and MPOD. Researches has show that MPOD is related to some ocular disease such as age-related macular degeneration, macular telangiectasia type 2, diabetic retinopathy, Stargardt disease et al. MPOD can be used in the judgment of clinical diagnosis, treatment effect. The specific mechanism of MP metabolism in the retina and in the pathogenesis of the disease, genotype specific nutritional therapy of xanthophyll, the establishment of a database combined with artificial intelligence and the rapid and convenient MP determination are all issues of great contention that need to be resolved.
MiRNAs are stable small RNAs that are expressed abundantly in animals and plants. They can bind to the 3'-untranslated region of the target mRNA, and regulate its expression at the post-transcriptional level. The miRNAs’ abnormal expression and its following abnormal biological regulation are closely related to the occurrence and development of age-related macular degeneration (AMD), including inflammatory response, oxidative stress injury, phagocytosis dysfunction and abnormal angiogenesis. Since the dysregulation of miR-155, miR-125b and miR-34a seems to play a more important role in AMD, these microRNAs may be expected to become the new biomarkers and therapeutic targets for AMD.
The etiology and pathogenesis of age-related macular degeneration (AMD) are unclear and difficult fot treatment. Some genetic research evidences in recent years have shown that the relationship between lipid metabolism-related gene polymorphism and AMD is statistically significant; it has also been found that blood lipid levels are related to AMD, and lipid-lowering drugs may have the effect of delaying the development of AMD in clinically. Abnormal lipid metabolism may play an important role in the occurrence and development of AMD. Clarifying the role of lipid metabolism in the occurrence and development of diseases will help reveal the pathogenesis of diseases and promote early diagnosis, monitoring and prevention of diseases, and provide an entry point for treatment.
Photoreceptor cells are special retinal neurons with photo-transformation ability. Loss of photoreceptors in age-related macular degeneration (AMD) is secondary to RPE loss, leakage of serum components from the neovascularization and scar formation, which is one of the main mechanisms of irreversible visual impairment in patients with AMD. Many studies have shown that inflammatory environment is involved in the process of photoreceptor cell death. Aging, photooxidation injury and other factors affects the retinal microenvironment through different levels of mechanisms such as retinal pigment epithelial cells, retinal glial cells, hematogenous macrophages and inflammatory factors, which results in photoreceptor injuries and participates in the progression of AMD by drusen formation and neovascularization. This study reviews the research status and progress of inflammation and photoreceptor cell death, and provides new ideas for exploring the blinding mechanism and treatment strategies of AMD.