Search results for "Retinal"
showing 10 items of 631 documents
Melanocortin receptor agonists MCR1-5protect photoreceptors from high-glucose damage and restore antioxidant enzymes in primary retinal cell culture
2016
Retinal photoreceptors are particularly vulnerable to local high-glucose concentrations. Oxidative stress is a risk factor for diabetic retinopathy development. Melanocortin receptors represent a family of G-protein-coupled receptors classified in five subtypes and are expressed in retina. Our previous data indicate that subtypes 1 and 5 receptor agonists exert a protective role on experimental diabetic retinopathy. This study focuses on their role in primary retinal cell cultures in high-glucose concentrations. After eye enucleation from wild-type male C57BL/6 mice, retinal cells were isolated, plated in high-glucose concentration and treated with melanocortin receptors 1 and 5 agonists an…
Retinal arteriole reactivity in mice lacking the endothelial nitric oxide synthase (eNOS) gene
2018
Dysfunctional vascular endothelial nitric oxide synthase (eNOS) has been proposed to play a main pathophysiological role in various ocular diseases. The aim of the present study was to test the hypothesis that the chronic lack of eNOS impairs endothelium-dependent vasodilation in retinal arterioles. The relevance of eNOS for mediating vascular responses was studied in retinal vascular preparations from eNOS-deficient mice (eNOS-/-) and wild-type controls in vitro. Changes in luminal diameter in response to vasoactive agents were measured by videomicroscopy. The thromboxane mimetic, U46619, induced similar concentration-dependent constriction of retinal arterioles in eNOS-/- and wild-type mi…
Pterostilbene Prevents Early Diabetic Retinopathy Alterations in a Rabbit Experimental Model
2019
Oxidative stress generated by diabetes plays a key role in the development of diabetic retinopathy (DR), a common diabetic complication. DR remains asymptomatic until it reaches advanced stages, which complicate its treatment. Although it is known that good metabolic control is essential for preventing DR, knowledge of the disease is incomplete and an effective treatment with no side effects is lacking. Pterostilbene (Pter), a natural stilbene with good antioxidant activity, has proved to beneficially affect different pathologies, including diabetes. Therefore, our study aimed to analyse the protective and/or therapeutic capacity of Pter against oxidant damage by characterising early retina…
Retinal and choroidal vasculature changes associated with chronic kidney disease
2018
Retinal and choroidal microvascular changes can be related to renal impairment in hypertension and chronic kidney disease (CKD). The study examines the association between retinochoroidal parameters and renal impairment in hypertensive, non-diabetic patients. This is a cross-sectional study on Caucasian patients with systemic arterial hypertension with different levels of renal function. All subjects were studied by blood chemistry, urine examination, microalbuminuria and blood pressure. Complete eye examination was completed with swept source optical coherence tomography (SS-OCT) and optical coherence tomography angiography (OCTA) scans of macular region. Patients were divided in groups: L…
Intravitreal ranibizumab treatment of retinal angiomatous proliferation
2010
. Purpose: To determine the efficacy of intravitreal injections of ranibizumab in the treatment of retinal angiomatous proliferation (RAP) in neovascular age-related macular degeneration. Methods: Retrospective, consecutive case series of 26 eyes (26 patients) treated with intravitreal injections of 0.5 mg ranibizumab for RAP. Patients received intravitreal injections at monthly intervals during upload phase for a 3-month period. Results: Mean visual acuity before treatment was 0.75 ± 0.38logMAR (mean ± SD, n = 26). In the upload phase, mean visual acuity improved 4 weeks after the initial injection to 0.6 ± 0.37logMAR (n = 26) and to 0.53 ± 0.34logMAR (n = 26) 4 weeks after the third mo…
Tomographic reconstruction reveals the morphology of a unique cellular organelle, the aggregated macrotubules (Macrotubuli aggregati) of human retina…
2014
Abstract Horizontal cells of the human retina contain unique tubular organelles that have a diameter which is about 10 times larger than that of microtubules (∼230 nm). These macrotubuli in most cases form regular aggregates. Therefore we propose to introduce them as Macrotubuli aggregati in the Terminologia histologica. Tomographic investigation of the structures revealed that the walls of the tubules most probably consist of intermediate filaments running nearly parallel to each other and show somewhat regularly attached ribosomes on their inner and also outer surface. About 2% of the organelles exhibit double- to multiple layered walls and less than 1% resemble large scrolls. The tubules…
Discrimination of retinal images containing bright lesions using sparse coded features and SVM
2015
Diabetic Retinopathy (DR) is a chronic progressive disease of the retinal microvasculature which is among the major causes of vision loss in the world. The diagnosis of DR is based on the detection of retinal lesions such as microaneurysms, exudates and drusen in retinal images acquired by a fundus camera. However, bright lesions such as exudates and drusen share similar appearances while being signs of different diseases. Therefore, discriminating between different types of lesions is of interest for improving screening performances. In this paper, we propose to use sparse coding techniques for retinal images classification. In particular, we are interested in discriminating between retina…
Intravitreal therapies for non-neovascular age-related macular degeneration with intraretinal or subretinal fluid
2017
OBJECTIVE: To evaluate the efficacy of intravitreal therapies in cases of atrophic age-related macular degeneration (AMD) with subretinal or intraretinal fluid. METHODS: A retrospective review was made of the clinical charts of patients diagnosed with atrophic AMD with subretinal or intraretinal fluid. Fundus photographs and spectral-domain optical coherence tomography images were examined, and an analysis was made on the presence of fluid and its density. Neovascularisation was ruled out by fluorescein and/or indocyanine green angiography. RESULTS: The study included 14 eyes from 13 patients with a mean age of 72.64 years and a mean follow-up of 80.5 weeks. Intraretinal fluid was observed …
Effectiveness of anti-vascular endothelial growth factors in neovascular age-related macular degeneration and variables associated with visual acuity…
2021
Objective To assess the overall effectiveness of anti-vascular endothelial growth factor (VEGF) therapy in treatment-naïve patients with neovascular age-related macular degeneration (nAMD) in a clinical practice setting. Study design EAGLE was a retrospective, 2-year, cohort observational, multicenter study conducted in Italy that analyzed secondary data of treatment-naïve patients with nAMD. The primary endpoint evaluated the mean annualized number of anti-VEGF injections at Years 1 and 2. The main secondary endpoints analyzed the mean change in visual acuity (VA) from baseline and variables associated with visual outcomes at Years 1 and 2. Results Of the 752 patients enrolled, 745 (99.07…
ApoB100,LDLR-/- mice exhibit reduced electroretinographic response and cholesteryl esters deposits in the retina
2008
International audience; PURPOSE. To evaluate the retinal phenotype of 7- and 14-month-old apoB100,LDLR–/– mice, a relevant animal model of lipid metabolism dysfunction. METHODS. Single-flash electroretinograms were obtained from 7- and 14-month-old apoB100,LDLR–/– and control mice fed a standard diet under both scotopic and photopic conditions. Visual cycle retinoids were analyzed in eyes from dark-adapted mice. Retinal and choroidal vascularization was evaluated with scanning laser ophthalmoscopy. Fatty acids were analyzed in the retina. Esterified and free cholesterol was detected in eye cryosections. RESULTS. Scotopic and photopic b-wave amplitudes were significantly reduced in apoB100,L…