Search results for "Retinal Pigment Epithelium"
showing 10 items of 62 documents
Assessment of the toxicity of cholesterol oxides on retinal pigment epithelial cultured cells
2006
International audience; Purpose: Among the retinal lipid deposits found in AMD (age related macular degeneration), esterified and unesterified cholesterol have been identified. Cholesterol that accumulates in Bruch's membrane could be oxidized and lead to cholesterol oxides known as oxysterols. These compounds have cytotoxic activities on many vascular cell types, and we conducted this study to evaluate the cytotoxics effects of oxysterols on retinal pigment epithelial (RPE) cells. Methods: Human RPE cells (ARPE–19) were cultured and treated by 7–ketocholesterol (7–keto), 7–betahydroxycholesterol (7–beta) and 25–hydroxycholesterol (25–OH). ARPE–19 cells viability was determined with MTT ana…
Gap junctions and connexin hemichannels both contribute to the electrical properties of retinal pigment epithelium.
2022
Gap junctions are intercellular channels that permit the transfer of ions and small molecules between adjacent cells. These cellular junctions are particularly dense in the retinal pigment epithelium (RPE), and their contribution to many retinal diseases has been recognized. While gap junctions have been implicated in several aspects of RPE physiology, their role in shaping the electrical properties of these cells has not been characterized in mammals. The role of gap junctions in the electrical properties of the RPE is particularly important considering the growing appreciation of RPE as excitable cells containing various voltage-gated channels. We used a whole-cell patch clamp to measure …
Electrofunctional features of the tilted disc syndrome.
1986
The ERG, EOG and VEPs of 15 patients with tilted disc syndrome were studied. The ERG showed abnormal amplitudes in about 1/4 of the eyes and the EOG values were pathological in 3 patients. It is probable that the abnormality of the inferior-nasal portion of the retina and retinal pigment epithelium seen in the tilted disc syndrome causes the changes in the ERG and EOG. Pattern VEPs latency was delayed in most patients. This finding is probably due to the poor focusing of the light in the retina.
Glaucomatous Maculopathy: Thickness Differences on Inner and Outer Macular Layers between Ocular Hypertension and Early Primary Open-Angle Glaucoma U…
2020
The purpose of this study was to compare the thickness of all inner and outer macular layers between ocular hypertension (OHT) and early primary open-angle glaucoma (POAG) using spectral domain optical coherence tomography (SD-OCT) 8 × 8 posterior pole algorithm (8 × 8 PPA). Fifty-seven eyes of 57 OHT individuals and fifty-seven eyes of 57 early POAG patients were included. The thickness of macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform and nuclear layer, photoreceptor layer (PRL) and retinal pigment epithelium were obtained in 64 cells for each macular layer and mean thickness of superior and inf…
Pilot Study on Visual Function and Fundus Autofluorescence Assessment in Diabetic Patients.
2015
Purpose. Evaluate optimized fundus autofluorescence (FAF) imaging in early stages of diabetic retinopathy (DR) and relate findings with conventional colour fundus imaging and visual function in diabetic patients and control subjects.Materials and Methods. FAF and colour images were obtained using the CR-2 Plus digital nonmydriatic retinal camera in seven diabetic patients and thirteen control subjects. Visual-Functioning Questionnaire-25 (VFQ-25) and Diabetes Self-Management Questionnaire (DSMQ) were used to assess the quality of life and diabetes self-care. Contrast sensitivity function (CSF) was evaluated with the Vistech 6500 chart.Results. FAF and optimized-FAF imaging showed more retin…
Development of choroidal neovascularization following transpupillary thermotherapy (TTT) for a small malignant melanoma of the choroid at the posteri…
2010
Abstract Introduction The malignant melanoma of the choroid is the most common primary malignant intraocular tumor in adults. There are currently several methods available for the treatment of choroidal melanomas. Among others, hyperthermia represents a therapeutic approach in which infrared radiation is delivered through the dilated pupil, called “transpupillary thermotherapy (TTT)”. The method was initially assumed to cause only a few side effects but gradually more and more complications have been observed. The treatment is associated with a number of vascular responses, for example arterial and venous occlusions. However neovascularizations of the choroid have only been detected twice s…
Laserfotokoagulation und photodynamische Therapie (PDT) zur Behandlung der retinalen angiomatösen Proliferation (RAP) bei feuchter altersabhängiger M…
2008
BACKGROUND: Retinal angiomatous proliferation (RAP) is a subtype of neovascular age-related macular degeneration (AMD) with particularly bad prognosis. Diverse treatment modalities are performed. PATIENTS AND METHODS: This is a retrospective review on the treatment results of 41 consecutive patients from 1 / 2003 to 12 / 2005 with RAP stage 1 - 3 (Yannuzzi classification), who were treated with laser photocoagulation, photodynamic therapy (PDT) and intravitreal injection of triamcinolone acetonide (IVT). Follow-up was 12 months minimally. RESULTS: In RAP stage I complete closure of the vascular lesion in 14 / 22 eyes was achieved by 1.2 ± 0.5 sessions of laser photocoagulation (4 × combined…
High-resolution images in macular disorders
2021
Objective: This study analyzed and compared the results of adaptive optics (AO) and fundus autofluorescence (FAF) in various maculopathies. Methods: The study included four different types of maculopathy: central serous chorioretinopathy (CSC), retinitis pigmentosa (RP), Stargardt disease (STGD) and phototoxic retinopathy. In all four cases, cone mosaic and cone density were obtained using AO fundus camera. Further, the high-resolution images were compared with the FAF and optical coherence tomography (OCT) results. Results: In CSC, FAF and AO, changes could be shown in the macula even two years after the subretinal fluid resorption, as opposed to a normal OCT. The improvement of FAF and co…
Spotlight on fundus autofluorescence.
2018
Fundus autofluorescence (FAF) imaging is based on the fluorescence from ocular endogenous fluorophores located in the retinal pigment epithelium and choroid, mainly lipofuscin and melanin. It is a noninvasive technique that provides information about the spatial distribution of lipofuscin/melanin and retinal pigment epithelium health status. An overview about the fluorophores responsible for FAF imaging and the usefulness of FAF imaging in the noninvasive assessment and monitoring of retinal diseases, such as age-related macular degeneration, diabetic retinopathy, diabetic macular edema, central serous chorioretinopthy, retinitis pigmentosa and retinal dystrophies, are discussed in this rev…
Combined effects of aging and a pro-diabetic diet on retinal function in a murine model of aging of the human eye
2009
; Purpose: Improvement of life expectancy and changes in the dietary behaviour of developed populations are accompanied with the prevalence of diabetes and age-related ocular pathologies. Aging of the retina is characterized by accumulation of lipids at the basement of the retinal pigment epithelium - Bruch’s membrane complex.Meanwhile increased oxidative stress is one of the features of aging and diabetes. A fructose-rich diet induces insulin resistance and hypertriglyceridemia, mimicking diabetes. The goal of our study was to evaluate the effects of a pro-diabetic fructose-enriched diet on the retinal function of the ApoB100,LDLR-/- mice, a murine model of aging of the human eye. Methods…