Epigenetic modifications such as DNA methylation, histone post-translational modifications, non-coding RNA are reversible, heritable alterations which are induced by environmental stimuli. Major risk factors of diabetes and diabetic complications including hyperglycemia, oxidative stress and advanced glycation end products, can lead to abnormal epigenetic modifications in retinal vascular endothelial cells and retinal pigment epithelium cells. Epigenetic mechanisms are involved in the pathogenesis of macular edema and neovascularization of diabetic retinopathy (DR), as well as diabetic metabolic memory. The heritable nature of epigenetic marks also playsakey role in familial diabetes mellitus. Further elucidation of epigenetic mechanisms in DR can open the way for the discovery of novel therapeutic targets to prevent DR progression.
To perform a meta-analysis of single nucleotide polymorphism needs to calculate gene frequency. This paper employs allele model as an example to introduce how to calculate gene frequency and display the process of a meta-analysis of single nucleotide polymorphism data using Review Manager 5.3 software.
Diabetic retinopathy (DR) is one of the most frequent complications of diabetes (T2DM), which is the main eye disease causing blindness in adults in recent years. At present, glucagon-like peptide-1 receptor agonists (GLP-1RA) have become the main drugs used in the treatment of diabetes due to its superior hypoglycemic, lipid-lowering, hypertensive and cardiovascular effects. A large number of studies have shown that GLP-1RA drugs can protect retinal microvascular and optic nerves in the treatment of diabetes through various ways, but some studies have found that GLP-1RA drugs represented by semaglutide may lead to the progress of DR. Therefore, GLP-1RA should be used cautiously for patients who with severe non-proliferative DR or proliferative DR. Regardless of whether T2DM patients are complicated with DR, the fundus retinal condition should be monitored regularly after the use of GLP-1RA drugs, and timely countermeasures should be taken when DR occurs and develops. The benefits of GLP-1RA used by diabetes patients are obvious to all, and scientific and rational drug use can prevent the occurrence and progress of DR, which can better benefit DR Patients.
Chronic disease is a major threat to human health. Fundus disease has become a major ophthalmic disease affecting daily life. Although great breakthroughs have been made in the treatment, compared with other chronic disease management, the management of patients with fundus disease is still in its infancy. To strengthen the management exploration of patients with fundus diseases, establish a management model of fundus diseases and strive to improve patients' awareness of fundus diseases and adherence to treatment and follow-up are the great challenges at present. All ophthalmic centers should strengthen patient education, establish a regional cooperation network, support the construction of grassroots medical capacity, cultivate talents, enhance training, promote the standardized treatment of fundus diseases, standardize fundus imaging inspection and diagnosis, and promote the homogeneous construction of diagnosis and treatment of chronic fundus diseases. We will accelerate the construction of a hierarchical diagnosis and treatment system and the ability to link consultation and referral. Through systematic management and intervention of fundus diseases, a large number of patients with fundus diseases will receive early screening, diagnosis, standardized continuous treatment and systematic management, and improve the quality of life of patients with fundus diseases.
Retinal degeneration mainly include age-related macular degeneration, retinitispigmentosa and Stargardt’s disease. Although its expression is slightly different, its pathogenesis is photoreceptor cells and/or retinal pigment epithelial (RPE) cel1 damage or degeneration. Because of the 1ack of self-repairing and renewal of retinal photoreceptor cells and RPE cells, cell replacement therapy is one of the most effective methods for treating such diseases.The stem cells currently used for the treatment of retinal degeneration include embryonicstem cells (ESC) and various adult stem cells, such as retinal stem cells (RSC), induced pluripotent stem cells (iPSC). and mesenchyma1 stem cells (MSC). Understanding the currentbasic and clinical application progress of ESC, iPSC, RSC, MSC can provide a new idea for the treatment of retinal degeneration.
Retinal neuronal cells are crucial in the formation of vision. Injury or death of these cells may lead to irreversible damage to visual function due to their low regenerative capacity. The P2X7 receptor is a trimeric adenosine triphosphate (ATP)-gated cation channel. Recent studies have shown that P2X7 receptor plays a role in retinal neuronal death. In a series of animal models, when exposed to conditions of hypoxia or ischemia, elevated ocular pressure, trauma and exogenous agonists, P2X7 receptor activated by extracellular ATP can cause death of retinal neuronal cells such as retinal ganglion cells and photoreceptor cells through direct or indirect pathways. Blocking the expression and function of P2X7 receptor by its specific antagonist and gene knocking-out, the loss of retinal neuronal cells is significantly attenuated. P2X7 receptor may become a potential novel neuroprotective target for diseases related to the loss of retinal neurons.
Age-related macular degeneration (AMD) is an age-related neurodegenerative eye disease characterized by degeneration and progressive death of retinal pigment epithelium (RPE) and photoreceptor cells. In recent years, as a new treatment for AMD, stem cell therapy has attracted wide attention in the field of AMD, and has become a current research hotspot. Although stem cell therapy carries risks such as increased incidence of cancer and immune rejection, it significantly promotes damaged photoreceptor cells and retinal cells by differentiating into RPE cells and other retinal cell types, as well as secreting neurotrophic factors and extracellular vesicles. In particular, the development of embryonic stem cell-derived RPE cells, its cryopreservation technology and the advancement of plasmid, adeno-associated virus, Sendai virus and other delivery technologies have laid a solid foundation for stem cell therapy of AMD. As a new method to prevent retinal damage and photoreceptor degeneration, stem cell neuroprotective therapy has shown great potential, and with the continuous maturity and improvement of these technologies, stem cell therapy is expected to provide new ideas for the prevention and treatment of AMD in the future.
Diabetic retinopathy (DR) is the most common cause of preventable blindness in the working-age population. In addition to optimizing the hyperglycemia, hypertension, hyperlipidemia and other risk factors, regular fundus examination is essential for early diagnosis asymptomatic DR and timely treat the sight-threatening DR, so as to reduce blindness and severe visual impairment caused by DR. Clinical practice guidelines for the screening and management of DR have been implemented throughout the world, but there are reasonable differences between existing guidelines in the recommended timing of first retinal examination, screening intervals, methods for examination and criteria for referral to an ophthalmologist. It is of great clinical significance to have a detailed understanding of the current guidelines for DR screening and their clinical basis.
Uric acid (UA) is the final product of human purine metabolism. As one of the main antioxidants in the body, it can scavenge oxidative radicals. Under the action of oxidative-antioxidant shuttle mechanism, the antioxidant activity of UA can be reversed, causing inflammation and oxidative stress of vascular endothelial cells. Hyperuricemia (HUA) is considered to be one of the major risk factors for diabetes and diabetic nephropathy. The study of HUA in diabetic retinopathy (DR) is also a hot topic. UA can cause retinal vascular sclerosis, and affect the occurrence and development of DR by promoting oxidative stress and inducing neovascularization.
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.