Search results for "Retinal"
showing 10 items of 631 documents
Primary vitrectomy for degenerative and tractional lamellar macular holes: A systematic review and meta-analysis
2021
Purpose To assess the efficacy of vitrectomy in degenerative and tractional lamellar macular holes (LMHs) by meta-analysis of published studies. Methods PubMed, Medline and Embase databases were searched up to May 2020. Included cohorts were divided into three groups: degenerative LMH group, lamellar hole associated epiretinal proliferation (LHEP) group and tractional LMH group. LHEP is likely to be associated with degenerative LMHs, but less commonly could be associated with mixed LMHs. To reduce risk of possible misclassification bias, eyes with LHEP which could not have been precisely classified by the authors, were included into the LHEP group. The primary outcome was to investigate th…
Role of retinal pigment epithelium-derived exosomes and autophagy in new blood vessel formation
2018
Autophagy and exosome secretion play important roles in a variety of physiological and disease states, including the development of age‐related macular degeneration. Previous studies have demonstrated that these cellular mechanisms share common pathways of activation. Low oxidative damage in ARPE‐19 cells, alters both autophagy and exosome biogenesis. Moreover, oxidative stress modifies the protein and genetic cargo of exosomes, possibly affecting the fate of surrounding cells. In order to understand the connection between these two mechanisms and their impact on angiogenesis, stressed ARPE‐19 cells were treated with a siRNA‐targeting Atg7, a key protein for the formation of autophagosomes.…
Alterations in Tight- and Adherens-Junction Proteins Related to Glaucoma Mimicked in the Organotypically Cultivated Mouse Retina Under Elevated Press…
2020
Purpose To scrutinize alterations in cellular interactions and cell signaling in the glaucomatous retina, mouse retinal explants were exposed to elevated pressure. Methods Retinal explants were prepared from C57bl6 mice and cultivated in a pressure chamber under normotensive (atmospheric pressure + 0 mm Hg), moderately elevated (30 mm Hg), and highly elevated (60 mm Hg) pressure conditions. The expression levels of proteins involved in the formation of tight junctions (zonula occludens 1 [ZO-1], occludin, and claudin-5) and adherens junctions (VE-cadherin and β-catenin) and in cell-signaling cascades (Cdc42 and activated Cdc42 kinase 1 [ACK1]), as well as the expression levels of the growth…
Cohen Syndrome-Associated Cataract Is Explained by VPS13B Functions in Lens Homeostasis and Is Modified by Additional Genetic Factors
2020
International audience; Purpose: Cohen syndrome (CS) is a rare genetic disorder caused by variants of the VPS13B gene. CS patients are affected with a severe form of retinal dystrophy, and in several cases cataracts also develop. The purpose of this study was to investigate the mechanisms and risk factors for cataract in CS, as well as to report on cataract surgeries in CS patients.Methods: To understand how VPS13B is associated with visual impairments in CS, we generated the Vps13b∆Ex3/∆Ex3 mouse model. Mice from 1 to 3 months of age were followed by ophthalmoscopy and slit-lamp examinations. Phenotypes were investigated by histology, immunohistochemistry, and western blot. Literature anal…
Modulation of the Immune System for the Treatment of Glaucoma
2017
Background At present intraocular pressure (IOP) lowering therapies are the only approach to treat glaucoma. Neuroprotective strategies to protect the retinal ganglion cells (RGC) from apoptosis are lacking to date. Substantial amount of research concerning the role of the immune system in glaucoma has been performed in the recent years. This review aims to analyse changes found in the peripheral immune system, as well as selected local changes of retina immune cells in the glaucomatous retina. Methods By dividing the immune system into the innate and the adaptive immune system, a systematic literature research was performed to find recent approaches concerning the modulation of the immune …
Tyro3 Contributes to Retinal Ganglion Cell Function, Survival and Dendritic Density in the Mouse Retina
2020
Retinal ganglion cells (RGCs) are the only output neurons of the vertebrate retina, integrating signals from other retinal neurons and transmitting information to the visual centers of the brain. The death of RGCs is a common outcome in many optic neuropathies, such as glaucoma, demyelinating optic neuritis and ischemic optic neuropathy, resulting in visual defects and blindness. There are currently no therapies in clinical use which can prevent RGC death in optic neuropathies; therefore, the identification of new targets for supporting RGC survival is crucial in the development of novel treatments for eye diseases. In this study we identify that the receptor tyrosine kinase, Tyro3, is crit…
Protective Effect of Astaxanthin on Primary Retinal Cells of the GerbilPsammomys ObesusCultured in DiabeticMilieu
2016
Astaxanthin is a major marine carotenoid with powerful antioxidant and neuroprotective properties. The in vitro protective effect of astaxanthin in adult retinal cells of the type-2 diabetic model Psammomys obesus in hyperglycemic conditions was investigated. Primary retinal cells were cultured in normal (5 mM) or high concentrations of glucose (25 and 40 mM) for 5 days and treated with 1–20 µM astaxanthin for the last 48 h of culturing. Mitochondrial dehydrogenase activity and cell viability were assessed using MTT test and trypan blue exclusion dye. Retinal cells were characterized by immunohistochemistry. The results showed that mitochondrial function increased significantly (P < 0.05) w…
What can visual caregivers expect with patients treated for SARS-CoV-2? An analysis of ongoing clinical trials and ocular side effects
2020
Within the COVID-19 pandemic context, the WHO has proposed a list of medicines to treat patients with severe acute respiratory syndrome (SARS-CoV-2). An analysis of their ocular side effects was performed. Only chloroquine and hydroxychloroquine were found to have an ocular impact in the medium and long-term. Detailed search strategies were performed in EMBASE, MEDLINE, SCOPUS and WOS Core Collection. Additionally, the worldwide ongoing clinical trials including chloroquine or hydroxychloroquine were evaluated, and their proposals of drug administration and exclusion criteria analyzed. In general, high maximum cumulative doses of chloroquine or hydroxychloroquine are being used for a short…
Ocular autofluorescence in diabetes mellitus. A review
2016
Diabetes mellitus is a metabolic disease with a considerable impact on healthcare owing to its increased prevalence and high mortality rate. Structural, morphological, and physiological changes in each of the ocular components have been described in detail. Autofluorescence has been described as a good indicator of metabolic activity. The aim of the present review is to provide an overview of ocular endogenous fluorophores in the cornea, the crystalline lens, and the retinal pigment epithelium, the effects of diabetes mellitus and therefore the potential of autofluorescence assessment for screening and monitoring changes in diabetic patients.
Confocal scanning laser ophthalmoscopy versus modified conventional fundus camera for fundus autofluorescence.
2016
Fundus autofluorescence (FAF) is a noninvasive imaging method to detect fundus endogenous fluorophores, mainly lipofuscin located in the retinal pigment epithelium (RPE). The FAF provides information about lipofuscin distribution and RPE health, and consequently an increased accumulation of lipofuscin has been correlated with ageing and development of certain retinal conditions. Areas covered: An exhaustive literature search in MEDLINE (via OVID) and PUBMED for articles related to ocular FAF in retinal diseases and different devices used for acquiring FAF imaging was conducted. Expert commentary: This review aims to show an overview about autofluorescence in the RPE and the main devices use…