Search results for " retina"

Systemische fibrinolytische Therapie mit Urokinase bei Zentralarterienverschluss der Netzhaut

2005

BACKGROUND AND OBJECTIVE Systemic fibrinolysis has become an important therapeutical option in patients with thrombotic occlusion of coronary or pulmonary arteries. In view of the hemorrhagic risk systemic fibrinolytic therapy for retinal vessel occlusion has been discussed controversial. In the present case study results and complications of systemic fibrinolysis should be investigated in patients with central retinal artery occlusion. PATIENTS AND METHODS From 1995 to 2002 a case series of 19 consecutive patients (8 female, 11 male, age: 63.2+/-14,3 years) with central retinal artery occlusion were treated by systemic application of urokinase using a standardized scheme. The latency from …

Treat and extend versus fixed regimen in neovascular age related macular degeneration: A systematic review and meta-analysis

2020

Purpose: To compare efficacy of treat and extend (T&E) versus fixed regimen treatment protocols in neovascular age-related macular degeneration (nAMD). Methods: Randomized clinical trials (RCTs) comparing T&E versus fixed regimen protocols for nAMD were systematically searched. Primary outcome was to compare the mean best corrected visual acuity (BCVA) change in T&E regimen versus fixed regimen. Secondary outcomes were change in the mean optical coherence tomography (OCT) central retinal thickness (CRT) and mean number of injections. Standardized mean difference (SMD) along with 95% confidence intervals (CIs) were calculated. Random-effect models were used for meta-analyses. Res…

Early OCTA Changes of Type 3 Macular Neovascularization Following Brolucizumab Intravitreal Injections

2022

Background and Objectives: Brolucizumab is a novel anti-vascular endothelial growth factor (VEGF), whose efficacy has been shown in the Hawk and Harrier phase 3 clinical studies. The goal of the present case series is to report initial results of brolucizumab intravitreal injections (IVI) on type 3 neovascularization in neovascular age-related macular degeneration (nAMD), evaluated by optical coherence tomography angiography (OCTA). Materials and Methods: This is a bicentric retrospective case series. Patients with newly diagnosed type 3 MNV treated with brolucizumab IVI and at least 6 months follow-up were enrolled. OCTA en face images and B-scans were analyzed for lesions at baseline, 1 m…

Classification of diabetes-related retinal diseases using a deep learning approach in optical coherence tomography

2019

Background and objectives: Spectral Domain Optical Coherence Tomography (SD-OCT) is a volumetric imaging technique that allows measuring patterns between layers such as small amounts of fluid. Since 2012, automatic medical image analysis performance has steadily increased through the use of deep learning models that automatically learn relevant features for specific tasks, instead of designing visual features manually. Nevertheless, providing insights and interpretation of the predictions made by the model is still a challenge. This paper describes a deep learning model able to detect medically interpretable information in relevant images from a volume to classify diabetes-related retinal d…

Xanthine oxidase catalyzes the oxidation of retinol.

2007

In mammals, xanthine oxidase (E.C. 1.17.3.2) catalyzes the hydroxylation of a wide variety of heterocyclic substrates such as purines, pyrimidines, and pterins, in addition to aldehydes [1] as all-trans-retinaldehyde [2-5]. Here, we show that buttermilk xanthine oxidase was capable to oxidizing all-trans-retinol (t-ROL) to all-trans-retinaldehyde (t-RAL) that was successively oxidized to all-trans-retinoic acid (t-RA). A rise in the enzyme activity, when t-ROL-CRBP complex was assayed, with respect to the free t-ROL, was observed. Furthermore, treatment of the enzyme with Na2S and glutathione resulted in a significant increment in catalytic activity toward t-ROL and t-RAL, due to the recons…

Circulating markers of retinal and optic nerve lipids

2013

Purpose Blood lipids are frequently used as a surrogate of lipid composition of peripheral tissues. Even if it is well accepted, such a relationship has never been clearly demonstrated for the eye. The aim of this study was to determine in human samples whether a lipidomic approach based on red blood cells could reveal associations between circulating and ocular lipid profiles. Methods Red blood cells, retinas and optic nerves were collected from 9 human donors. The lipidomic analyses on these tissues were done by both, gas chromatography and liquid chromatography coupled to an electrospray ionization source-mass spectrometer (LC-ESI-MS/MS). Results Gas chromatographic approach did not show…

Statistical atlas based exudate segmentation

2013

International audience; Diabetic macular edema (DME) is characterized by hard exudates. In this article, we propose a novel statistical atlas based method for segmentation of such exudates. Any test fundus image is first warped on the atlas co-ordinate and then a distance map is obtained with the mean atlas image. This leaves behind the candidate lesions. Post-processing schemes are introduced for final segmentation of the exudate. Experiments with the publicly available HEI-MED data-set shows good performance of the method. A lesion localization fraction of 82.5% at 35% of non-lesion localization fraction on the FROC curve is obtained. The method is also compared to few most recent referen…

Role of Oxidative Stress in Aging of the Retina in the ApoB100,LDLR-/- Mouse, a Murine Model of Aging of the Human Retina

2009

Involvement of plasmalogens and iPLA2 in the control of post-natal retinal vascular development in mice

2014

International audience; Purpose: The correct development of retinal blood vessels is essential to ensure vision process through sufficient oxygen and nutrient supplies to the retina. It was shown that polyunsaturated fatty acids (PUFAs) could modulate factors involved in tissue vascularization. A congenital deficiency in ether-phospholipids also termed as "plasmalogens" was shown to lead to abnormal ocular vascularization. Because plasmalogens are considered as reservoirs of PUFAs, we wanted to better understand the mechanisms by which plasmalogens may regulate retinal vascular development through the release of PUFAs by a calcium-independent phospholipase A2 (iPLA2). Methods: Retinal vascu…

Dietary ω3 fatty acids & metabolic syndrome in the rat: consequences on sensitivity and retinal functionality

2014

International audience; Purpose: High fructose diets have been widely used to trigger metabolic syndrome (MetS) in rodents. Insulin resistance is a major risk factor for the development of type 2 diabetes leading in 30 to 40% of the cases to the development of diabetic retinopathy in humans. In the other hand, ω3 fatty acids have been associated with the prevention of MetS. Few studies have been interested in the early changes occurring in the retina after induction of MetS and to potential of ω3 fatty acids to reverse those effects. Methods: 96 male Brown Norway rats (6 weeks of age) were fed for 3 and 8 days with either of the four following diets (n=8 in each group): a regular chow diet …