There are lots of imaging technologies in the ocular fundus disease field, including ultrasound biomicroscopy (UBM), fundus fluorescein angiography (FFA), indocynine green angiography (ICGA), fundus photograph (FP) and Optical Coherence Tomography (OCT). However there is no standard for image formats among various fundus imaging equipment, technology application processes, thus the relevant data cannot be compared and analyzed. And improper operation of the instruments causes unstable image quality or image missing. Also lack of appropriate evaluation guidelines results in different interpretation of same image data. These three factors not only affect the fundus imaging device application efficiency, limit the sharing of fundus imaging resource, but also hinder the development of fundus imaging diagnostic applications. Therefore, instrument types, data acquisition protocol and data presenting formats should be standardized for ocular fundus image acquisition. The technicians who operate the machine should be trained regularly to follow the standard operating procedure of data acquiring, thus to ensure integrity, truthful and reliable data is collected. In order to enhance the application efficiency of fundus imaging equipment, save public health resources, to promote fundus imaging diagnostic technology development, we need to develop evaluation guidelines for fundus image data, establish a comprehensive system including remote consultation center, reading center and quality control center.
Since anti-vascular endothelial growth factor (VEGF) therapy has recently become the first-line treatment of wet age related macular degeneration in China, as well as retinopathy of prematurity, neovascular glaucoma and macular edema secondary to diabetic retinopathy or retinal vein occlusion in other countries. It is worth thinking about that how to perform anti-VEGF treatment properly to benefit more patients. We reviewed the fields of clinical researches to explore the best role of anti-VEGF treatment in prevention and treatment of retinal disease in future.
Diabetic macular edema (DME) is the main cause of visual impairment in diabetic retinopathy patients. It mainly includes focal DME and diffuse DME, while DME of clinical significance needs timely intervention treatment. Optical coherence tomography is currently recognized as the most sensitive method to accurately diagnose DME. Currently, the common treatments of DME include intravitreal injection of anti-vascular endothelial growth factor (VEGF) or glucocorticoid and laser photocoagulation. Among them, anti-VEGF injection is becoming the first-line therapeutic, and corresponding individual treatment or combined treatment strategy should be selected according to the characteristics of DME and the specific conditions of patients. During the diagnosis and treatment of DME, attention should be paid to the systemic treatment of diabetes and the effect of diabetes-related neuroretinopathy on the therapeutic effect of DME. With the appearance of heterogeneity in the efficacy of anti-VEGF drugs, it remains to be further studied how to choose alternative therapeutics and when to replace them.
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.
Intravitreal injection of anti-VEGF drugs has gradually become the first-line treatment for diabetic retinopathy (DR). However, diabetic macular edema (DME) caused by DR blood-retinal barrier damage is less sensitive to anti-VEGF drugs.Therefore, it is necessary to find supplementary drugs or alternative drugs that can effectively protect the structure of the blood vessel wall. Melatonin is a hormone mainly secreted by the pineal gland, which can play a number of functions in the human body such as regulating biological rhythms, scavenging free radicals, and anti-inflammatory. In recent years, studies have shown that melatonin can improve neuronal degeneration and protect blood vessel structure through multiple mechanisms in retinopathy. In terms of its protective effect on the retinal capillary structure, melatonin can improve the damage of early DR endothelial cells and pericytes through anti-oxidative stress, anti-inflammatory, and inhibiting cell apoptosis so as to protect the integrity of the blood-retinal barrier structure. It suggests that melatonin may provide new ideas for the prevention and treatment of DR, especially with DME.
Myopia has become a major problem that threatens human health worldwide. Complications caused by high myopia are one of the leading causes of low vision and blindness. As a chronic disease that seriously threatens ocular health in the clinical practice and public health fields, the prevention and control of high myopia should actively promote a tertiary prevention strategy, and take advantages of the latest fundus imaging technology and big data technology, artificial intelligence to explore the evolution mechanism of “myopia→high myopia→pathological myopia”. Special efforts should be focused on the establishment of a scientific myopia prediction model, implementation of effective high myopia monitoring and management, and early detection and treatment of complications of high myopia to reduce the incidence of low vision and blindness.
摘要:眼部的局部给药方式影响着药物作用的强度,速率及持续时间和不良反应。视网膜,脉络膜,玻璃体及视神经的疾病则对眼后节的局部给药治疗提出了挑战,以局部给药的方式通过解剖学的膜屏障及泪液排泄,并达到在特定部位起治疗作用的药物浓度是其中的重要课题。全身给药则难以在眼组织积蓄足够的药物浓度,且易引起全身性的不良反应。眼表局部应用滴眼剂在泪液循环及角膜,结膜的屏障作用下易发生流失,而有创的给药方式包括玻璃体内注射,结膜下注射等变得越来越普遍的同时,除对病人造成疼痛不适外,甚至也可导致多种严重于疾病本身的并发症。本文综述了近几年来随着各种眼科疾病分子机制的研究和解明,眼部局部给药方式及新剂型的药代动力学及安全性的研究进展。Abstract: The ocular drug delivery system affects the drug’s efficacy,rate of speed,velocity and adverse reaction.How to deliver the drug with therapeutic local concentrations to the posterior segment remains a challenge. Many invasive methods such as intravitreal injection,subconjunctival injection are generally used,noninvasive method like eye drop can not pass through the barrier of the eye although it is convenient.The recent progress in safty and pharmacokinetic of ocular drug delivery system is reviewed in this article.
The mineralocorticoid receptor (MR) belongs to the nuclear receptor superfamily and is expressed in the retina and choroid. MR antagonist (MRA) has a long history of application in non-ophthalmic clinical practice. Various cellular and animal models indicated that inappropriate activation of MR participated in pathological angiogenesis, oxidative stress, inflammation, disturbance of ion/water homeostasis and neurodegenerative changes, while the application of MRA can reduce or reverse these pathological processes. After using MRA in central serous chorioretinopathy (CSC) patients, improved visual function, less subretinal fluid and reduced sub-foveal choroidal thickness were observed. Single nucleotide polymorphisms in MR and plasma aldosterone levels were significantly different between chronic CSC patients and CSC patients with spontaneous remission. Novel formulation for sustained-release MRA and the mechanisms involving inflammation may become the new focus of MR study. This review summarizes the research status of MR and MRA in order to provide a reference for future basic research and clinical treatment.