Search results for "Retina"
showing 10 items of 864 documents
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…
Synaptic ribbons, spheres and intermediate structures in the developing rat retina
1992
The present study was conducted to investigate the qualitative and quantitative development of synaptic bodies in retinae of Wistar rats during postnatal days 4-28. In addition, the effects of different light regimens and of eye pigmentation on SB numbers were studied. Synaptic bodies were counted and measured in the outer plexiform layer of retinal tissue fixed and processed by routine electron microscopical techniques. At postnatal days 4 and 5, retinae showed only few synaptic bodies. The main numerical development of synaptic bodies occurred between postnatal days 4 and 9, numbers remaining more or less constant thereafter. The intracellular location of synaptic ribbons changed from pre…
Immunological Effects of Allopurinol in the Treatment of Experimental Autoimmune Uveitis (EAU) after Onset of the Disease
2003
Purpose Allopurinol reduces oxidative tissue damage and exerts immunomodulating effects in the treatment of experimental autoimmune uveitis (EAU). However, the mechanism of the immunologic pathway remains unclear. In previous studies, treatment was started at the time of immunization. Therefore, whether allopurinol prevents the onset of the disease (i.e., acts in a protective manner) is not known. Methods Sixteen male Lewis rats were used: 6 EAU without therapy [control]; 4 EAU with allopurinol treatment starting 7 days after immunization [AL7]; and 6 EAU with allopurinol treatment starting 11 days after immunization [AL11]. Their sera were tested against Western blots of sodium dodecyl sul…
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…
Olfacto-retinalis pathway in Austrolebias charrua fishes: A neuronal tracer study
2013
Abstract The olfacto-retinal centrifugal system, a constant component of the central nervous system that appears to exist in all vertebrate groups, is part of the terminal nerve (TN) complex. TN allows the integration of different sensory modalities, and its anatomic variability may have functional and evolutionary significance. We propose that the olfacto-retinal branch of TN is an important anatomical link that allows the functional interaction between olfactory and visual systems in Austrolebias . By injecting three different neuronal tracers (biocytin, horseradish peroxidase, and 1,1′-dioctadecyl-3,3,3′,3′tetramethyl-indocarbocyanine perchlorate (DiI)) in the left eye of Austrolebias ch…
Anterograde tracing of retinal afferents to the tree shrew hypothalamus and raphe
2000
The anterograde neuronal transport of Cholera toxin B subunit (CTB) was used in this study to label the termination of retinal afferents in the hypothalamus of the tree shrew Tupaia belangeri. Upon pressure-injection of the substance into the vitreous body of one eye, a major projection of the retinohypothalamic tract (RHT) was found to the hypothalamic suprachiasmatic nuclei (SCN). Although the innervation pattern was bilateral, the ipsilateral SCN received a somewhat stronger projection. Labeling was also found in the supraoptic nucleus and its perinuclear zone, respectively, mainly ipsilaterally as well as in the bilateral para- and periventricular hypothalamic regions without lateral pr…
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 …