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.
Central serous chorioretinitis (CSC) is a kind of choroidal retinopathy characterized by choroidal vasodilatation and hyperpermeability, retinal pigment epithelial cell lesions and serous retinal detachment. Various imaging examinations and imaging techniques have been used to describe the characteristics of the retina and choroid. Fundus manifestations of different types of CSC has both generality, and have their respective characteristic. The classification of CSC and its differentiation from other diseases including the choroidal neovascularization and pachychoroidopathy spectrum depending on varieties of fundus imaging techniques. The current study aims to review the various performance characteristics of CSC especially for chronic CSC with multimodal imaging and the current research progress, so as to provide reference for ophthalmologists to more comprehensively and intuitively understand the clinical characteristics and potential pathogenesis of CSC, and also to provide basis for multimodal imaging assisted diagnosis and treatment.
X-linked retinoschisis (XLRS) is a rare X-linked inherited retinal disorder, caused by mutations in retinoschisin 1 (RS1) gene. Three XLRS mice were established, providing ideal systems to study the mechanism and treatment methods for XLRS. RS1 gene mutations can induce abnormal secretion or adhesion function of RS1 protein. In the past year, phase I clinical trials for XLRS has begun in USA, using adeno associated virus (AAV, AAV8 or AAV2)-mediated gene delivery. With the rapid development of new generation of AAV vector that can transduce more retinal cells through intravitreous delivery, gene therapy for XLRS will have a brighter future.
The pathogenesis of diabetic retinopathy (DR) is complex and there are many related risk factors. It is related to the course of diabetes, blood glucose, blood pressure, and blood lipids, among which the course of disease and hyperglycemia are recognized main risk factors. In addition, other factors which include heredity, gender, age, obesity, pregnancy, insulin use, can also affect the occurrence and development of DR, but there is no unified conclusion about its correlation. A comprehensive understanding of the risk factors that affect DR can provide new ideas for the prevention, diagnosis, treatment, and intervention of DR.
Peripheral exudative hemorrhagic chorioretinopathy (PEHCR) is a peripheral retinal disease characterized by subretinal hemorrhage and/or subretinal pigment epithelial hemorrhage or exudation. It is often misdiagnosed as age-related macular degeneration, polypoidal chorioretinopathy or choroidal melanoma. With the development of multimodal imaging, PEHCR has different features under different examinations, such as B-scan ultrasound, fluorescein fundus angiography, optical coherence tomography and so on, which contributes to differention from other diseases. Clinical treatments for the disease include intravitreal injection of retinal photocoagulation therapy, anti-vascular endothelial growth factor, pars plana vitrectomyand so on, but there is still no universal consensus. In order to gain a deeper understanding of the clinical features, treatment options and prognosis of PEHCR, minimize missed diagnoses and misdiagnoses, and improve treatment efficiency, further research is required.
Open-globe injuries (OGI) result in complicated and diverse conditions with different mechanisms and anatomical locations, which lead to completely different outcomes based on when to perform pars plana vitrectomy (PPV) after trauma. The PPV operation time points are generally divided into early (0 - 3 days), delayed (4 - 14 days), and late (> 2 weeks). There are still some controversies about the PPV time points after OGI. Injuries with intraocular foreign bodies or high risk of infection usually need early surgery to reduce the occurrence of endophthalmitis. However corneal edema and vitreous hemorrhage can increase the difficulties for early diagnosis and surgery. If there is choroidal hemorrhage or severe trauma in the back part of the eye, delayed intervention can allow the blood clots to be liquefied and removed easily. But there is higher incidence of postoperative complications. Late surgery can reduce the difficulty of PPV, but the increased incidence of proliferative vitreoretinopathy may lead to severe retinal traction, tears and postoperative scar formation.
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.
Idiopathic macular hole (IMH) refers to full thickness defects of retina in macular area with no clear reasons. The management of IMH includes vitrectomy combined with internal limiting membrane (ILM) peeling and pharmacological vitreolysis. But ILM peeling may damage the inner retina; novel techniques, such as inverted ILM flap technique and foveola non-peeling ILM surgery, autologous ILM transplantation had made the method of ILM peeling more diversified with less damage. Pharmacological vitreolysis targeting fibronectin and laminin is considered to work in a two-step mechanism, involving both vitreoretinal separation and vitreous liquefaction. Furthermore, IMH judgment and prognosis indicators like ellipsoid zone, macular hole index, hole formation factor, diameter hole index and tractional hole index based on spectral domain optical coherence tomography enriched the assessment of macular hole diameter, depth and shape. How to make full use of new interventions to reduce the incidence of macular hole and obtain a better visual acuity with closed holes is an important direction for future research.
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.