scholarly journals MR pathway in retinal health and diseases

Author(s):  
Francine Behar-Cohen ◽  
Min Zhao

In the retina, mineralocorticoid receptor (MR), expressed in vessels, glial and neuronal cells, is mainly activated by glucocorticoids. Under pathological conditions, ocular MR expression and corticoids change, leading in most cases to MR overactivation. Experimental models using MR agonists or antagonists, administered systemically or intraocularly, acutely or chronically and transgenic models, allowed to identify the deleterious consequences of MR pathway overactivation. Among them, oxidative stress, inflammation, deregulation of hydro-ionic channels, alteration of choroidal vasculature, angiogenesis and cell death, are common to major retinal diseases. Specific MR antagonists showed efficacy in models of diabetic retinopathy, ischaemia, retinal and choroidal angiogenesis and in models of glaucoma. It is highly likely that MR antagonists will find a place in the therapeutic arsenal of age-related macular degeneration, diabetic retinopathy, glaucoma and in pachychoroid associated diseases. Their use in humans is still limited by the need of biomarkers of MR activation and specific ocular formulations.

2018 ◽  
Vol 1 (1) ◽  
pp. 62-70
Author(s):  
Juhn AT ◽  
Shyu AP ◽  
Benjamin J ◽  
Zhang Y

Subthreshold Diode Micropulse (SDM) laser is a relatively new treatment modality that confers very little to no anatomical risk to the retina. However, its efficacy is still being studied, and the scenario where SDM is most useful is still being elucidated. This paper reviews articles from 1997 to 2017 and reviews the settings, results, and outcomes of SDM in various clinical settings including diabetic macular edema, branch retinal vein occlusion, central serous Chorioretinopathy, proliferative diabetic retinopathy, and age-related macular degeneration.


2020 ◽  
Vol 258 (4) ◽  
pp. 805-813 ◽  
Author(s):  
Andrzej Grzybowski ◽  
Piotr Kanclerz ◽  
Raimo Tuuminen

Abstract Purpose Multifocal intraocular lenses (MIOLs) are often discouraged in patients with or at risk of retinal disorders (including diabetic retinopathy, age-related macular degeneration, and epiretinal membranes), as MIOLs are believed to reduce contrast sensitivity (CS). Concerns with MIOLs have also been raised in individuals with visual field defects, fixation instability or eccentric preferred retinal locations. The aim of this study is to review the influence of MIOL on quality of vision in patients with retinal diseases. Methods We reviewed the PubMed and Web of Science databases to identify relevant studies using the following keywords: multifocal intraocular lens, cataract surgery, cataract extraction, lens exchange, diabetic retinopathy, age-related macular degeneration, and contrast sensitivity. Results Studies evaluating CS in MIOLs present conflicting results: MIOLs either did not influence CS or resulted in worse performance under low-illuminance conditions and higher spatial frequencies when compared to monofocal IOLs. Nevertheless, MIOLs preserved CS levels within the age-matched normal range. Two studies reported that patients with concurrent retinal diseases receiving a MIOL, both unilaterally and bilaterally, reported a significant improvement in visual-related outcomes. Individuals with a monofocal IOL in one eye and a MIOL in the fellow eye reported greater subjective satisfaction with the MIOL. Conclusion We were unable to find evidence suggesting that patients with retinal diseases should be advised against MIOLs. Nevertheless, more research is needed to address the aforementioned concerns and to optimize the use of MIOLs in eyes with retinal disease.


2009 ◽  
Vol 03 (02) ◽  
pp. 105 ◽  
Author(s):  
José Cunha-Vaz ◽  

The blood–ocular barrier system is formed by two main barriers: the blood–aqueous barrier and the blood–retinal barrier (BRB). The BRB is particularly tight and restrictive and is a physiological barrier that regulates ion, protein and water flux into and out of the retina. The BRB consists of inner and outer components, the inner BRB being formed of tight junctions between retinal capillary endothelial cells and the outer BRB of tight junctions between retinal pigment epithelial cells. The BRB is essential to maintaining the eye as a privileged site and is essential for normal visual function. Alterations of the BRB play a crucial role in the development of retinal diseases. The two most frequent and relevant retinal diseases, diabetic retinopathy and age-related macular degeneration (AMD), are directly associated with alterations of the BRB. Diabetic retinopathy is initiated by an alteration of the inner BRB and neovascular AMD is a result of an alteration of the outer BRB. Treatment of retinal diseases must also deal with the BRB either by using its specific transport mechanisms or by circumventing it through intravitreal injections


2021 ◽  
Vol 22 (12) ◽  
pp. 6207
Author(s):  
Radoslaw Kaczmarek ◽  
Pawel Gajdzis ◽  
Malgorzata Gajdzis

Retinal diseases are the leading cause of irreversible blindness. They affect people of all ages, from newborns in retinopathy of prematurity, through age-independent diabetic retinopathy and complications of retinal detachment, to age-related macular degeneration (AMD), which occurs mainly in the elderly. Generally speaking, the causes of all problems are disturbances in blood supply, hypoxia, the formation of abnormal blood vessels, and fibrosis. Although the detailed mechanisms underlying them are varied, the common point is the involvement of Eph receptors and ephrins in their pathogenesis. In our study, we briefly discussed the pathophysiology of the most common retinal diseases (diabetic retinopathy, retinopathy of prematurity, proliferative vitreoretinopathy, and choroidal neovascularization) and collected available research results on the role of Eph and ephrins. We also discussed the safety aspect of the use of drugs acting on Eph and ephrin for ophthalmic indications.


2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Yang Yu ◽  
Licheng Li ◽  
Shu Lin ◽  
Jianmin Hu

AbstractAge-related macular degeneration, diabetic retinopathy, retinitis pigmentosa and other retinal disorders are the main causes of visual impairment worldwide. In the past, these retinal diseases, especially dry age-related macular degeneration, proliferative diabetic retinopathy and retinitis pigmentosa, were treated with traditional surgery and drugs. However, the effect was moderate. In recent years, researchers have used embryonic stem cells, induced pluripotent stem cells, mesenchymal stem cells, olfactory ensheathing cells and other stem cells to conduct experiments and found that stem cells can inhibit inflammation, regulate immune response, secrete neurotrophic factors, and differentiate into retinal cells to replace and promote restoration of the damaged parts. These stem cells have the potential to treat retinal diseases. Whether it is in animal experiments or clinical trials, the increase in the number of retinal cells, maintenance of function and improvement of visual function all reflect the advanced of stem cells to treat retinal diseases, but its risk preserves the donor’s hidden pathogenic genes, immune rejection and tumorigenicity. With the development of exosomes study, researchers have discovered that exosomes come from a wide range of sources and can be secreted by almost all types of cells. Using exosomes with stem cell to treat retinal diseases is more effective than using stem cells alone. This review article summarizes the recent advances in the application of olfactory ensheathing cells and stem cells/exosomes in the treatment of retinal disorders.


In this paper, a detail survey on retinal diseases identification using image processing is discussed. The retinal diseases are glaucoma, cataract, hypersensitive retinopathy, diabetic retinopathy, age related macular degeneration. The image processing provides greater innovation in medical applications. Image processing gives clear view to determine the infected area. Different algorithms and different procedure were followed here. The survey of detection in retinal diseases includes algorithms are elaborated and compared which are useful for researchers in image processing .This help the researcher get a detailed view of image processing in retinal diseases identification.


2021 ◽  
Vol 59 (241) ◽  
pp. 858-861
Author(s):  
Arjun Shrestha ◽  
Rinkal Suwal ◽  
Rajan Shrestha ◽  
Barsha Suwal ◽  
Deepak Khadka

Introduction: Intravitreal Bevacizumab injection has now become a routine procedure for retina specialists throughout the world. Easy availability of this monoclonal antibody molecule even in Nepal has brought a revolution in the management of various retinal diseases. This study aims to find out the prevalence of the use of intravitreal Bevacizumab for retinal diseases at the tertiary eye hospital. Methods: This descriptive cross-sectional study was carried out in the retina department at a tertiary care hospital from January 2017 to December 2019 after obtaining ethical clearance from Nepal Health Research Council (Ref: 125/2020P). The sample size was calculated and the study enrolled all patients who received intravitreal Bevacizumab for retinal diseases using convenience sampling technique. Data were analyzed using Statistical Package for Social Science Version 21. Point estimate at 95% Confidence Interval was calculated, along with frequency and percentage for binary data. Results: Out of 959 total surgical retinal interventions done 296 (30.86%) at 95% Confidence Interval (27.93-33.78) patients received intravitreal Bevacizumab. Out of total intravitreal Bevacizumab injections, 143 (36.7%) injections were given to retinal vein occlusions patients, 127 (32.6%) injections were given to diabetic retinopathy patients and 66 (17%) injections was given to age-related macular degeneration patients. Males 176 (59.5%) outnumbered the females 120 (40.5%) in receiving intravitreal Bevacizumab. Mean baseline Logarithm of the Minimal Angle of Resolution visual acuity, 1.1, improved to, 0.75, after 3 months of intravitreal Bevacizumab. Conclusions: Intravitreal Bevacizumab was one of the commonest retinal interventions used. Retinal vein occlusion, diabetic retinopathy, and age-related macular degeneration were the commonest retinal diseases needing intravitreal Bevacizumab.


2020 ◽  
Author(s):  
Aswini Poyyakkara ◽  
Sruthi Thekkeveedu ◽  
Sharath S. Shankar ◽  
V.B. Sameer Kumar

Angiogenesis is an indispensable biological process, any aberrancy associated with which can lead to pathological manifestations. To manage different pathological conditions associated with abnormal angiogenesis, Nanomaterial based formulations have been tested in in vitro and in vivo models by different groups. The research advancements pertaining to the applications of major candidate nanomaterials for the treatment of pathologies like tumor, cardiovascular diseases, diabetic retinopathy, age related macular degeneration, chronic wounds, impaired osteogenesis and nerve tissue degeneration, have been briefed in this chapter.


Sign in / Sign up

Export Citation Format

Share Document