Search results for "optic nerve"

Dynamics, alterations, and consequences of minimally invasive intraocular pressure elevation in rats.

2014

PURPOSE: An important, yet not exclusive, aspect of primary open angle glaucoma is elevated intraocular pressure (IOP) profiles within fluctuations and pressure peaks. The study aimed at establishing minimally invasive methods for recurrent IOP elevation in rats to investigate the impact of IOP dynamics and pathomorphologic retinal alterations during and after IOP elevation. METHODS: Intraocular pressure was elevated unilaterally in Long Evans rats to a level of ≈35 mm Hg for 1 hour in a total of 30 manipulations within 6 weeks, by using two methods: (1) suction-cup oculopression and (2) loop-adjusted oculopression. Retinal thickness (RT) was measured via optical coherence tomography (OCT),…

Changes in visual function and retinal structure in the progression of Alzheimer's disease

2019

Background Alzheimer's Disease (AD) can cause degeneration in the retina and optic nerve either directly, as a result of amyloid beta deposits, or secondarily, as a result of the degradation of the visual cortex. These effects raise the possibility that tracking ophthalmologic changes in the retina can be used to assess neurodegeneration in AD. This study aimed to detect retinal changes and associated functional changes in three groups of patients consisting of AD patients with mild disease, AD patients with moderate disease and healthy controls by using non-invasive psychophysical ophthalmological tests and optical coherence tomography (OCT). Methods We included 39 patients with mild AD, 2…

Sonic hedgehog promotes the migration and proliferation of optic nerve oligodendrocyte precursors.

2007

Optic nerve (ON) oligodendrocyte precursors (OPCs) are generated under the influence of the Sonic hedgehog (Shh) in the preoptic area from where they migrate to colonise the entire nerve. The molecular events that control this migration are still poorly understood. Recent studies suggested that Shh is often used by the same cell population to control different processes, including cell proliferation and migration, raising the possibility that Shh could contribute to these aspects of OPC development. In support of this idea, we show here that Shh induces the proliferation of OPCs derived from embryonic mouse ON explants and acts as a chemoattractant for their migration. In ovo injections of …

The Forebrain of the Blind Cave Fish <i>Astyanax hubbsi </i>(Characidae)

1997

This paper presents a survey of the cell groups in the telencephalon of the teleost Astyanax hubbsi, based on series of transverse sections stained with the Nissl-Kluver-Barrera and Bodian procedures. The work was conducted for two reasons. Firstly, it was intended to determine the contribution of the forebrain of blind cave fish to certain forms of behavior. An understanding of the anatomy of the telencephalic organization is essential for such a neuroethological approach. The second purpose was to provide the cytoarchitectural basis for the experimental analysis of the fiber connectivity of the telencephalon of A. hubbsi. Furthermore, information about the forebrain of characids is widely…

Systemic therapies for mucopolysaccharidosis: ocular changes following haematopoietic stem cell transplantation or enzyme replacement therapy - a rev…

2010

The management of mucopolysaccharidosis (MPS) is focused on the multi-organ, sometimes life-threatening, clinical manifestations that occur over time. In the past, the limited, symptom-based treatment options led physicians to adopt a palliative approach towards individual disease-associated complications. The availability of systemic treatments such as haematopoietic stem cell transplantation (HSCT) and enzyme replacement therapy (ERT) has created a better prognosis for MPS patients, particularly when initiated early in life. As part of an integrated management approach, these therapies could be valuable in managing the ocular features that are present in many children with MPS. HSCT has b…

Anatomy of the visual system

2004

This brief systemic overview presents the anatomic details of the orbit with respect to imaging modalities CT and MR. The structures of the four orbital compartments, intrakonal and extrakonal space, globe and optic nerve are demonstrated in detail on different CT and MR views (axial, coronal, in soft tissue and bone window, T1-weighted, T2-weighted) with corresponding diagrams. The intracranial visual pathway is explained in detail with emphasis to the striate cortex and extrastriate visual association cortex, presented with diagrams and high-resolution MR.

Computed Tomography in Orbital Lesions

1981

Lesions in the orbits are characterized by unilateral or bilateral proptosis and/or disorders of ocular motion. Before the advent of computed tomography diagnosis was made on the basis of conventional radiological studies of the skull and the orbits as well as with ultrasonog-raphy, fluorescence angiography, phlebography of the ophthalmic vein, and arteriograms of the internal and external carotid arteries. The introduction of CT has brought about a correspondingdecline in the use of invasive procedures (Wende et al. 1977).

2017

Purpose To compare two surgical approaches for treating encapsulated blebs after trabeculectomy with mitomycin C, in terms of the development of intraocular pressure and progression of glaucoma in a long-term follow up: 1. bleb needling alone vs. 2. a combined approach of needling with additional transconjunctival scleral flap sutures, to prevent early ocular hypotony. Methods Forty-six patients with failing blebs after trabeculectomy with mitomycin C were enrolled in this study. Patients received either needling revision alone (group 1; n = 23) or a combined needling with additional transconjuctival flap sutures, if intraoperatively the intraocular pressure was estimated to be low (group 2…

Dietary polyunsaturated fatty acids, intraocular pressure, and glaucoma

2014

Abstract Glaucoma is a progressive optic neuropathy and is the second leading cause of blindness worldwide. Estimations predict that nearly 80 million people will be affected by the disease in 2020. Increased intraocular pressure (IOP) has been recognized as a major risk factor for developing glaucoma. Although IOP-lowering agents have been shown to be effective for decreasing the progression of glaucoma, extensive research has been done to identify modifiable lifestyle factors involved in the pathogenesis of this disease. Among these factors, dietary lipids and particularly dietary polyunsaturated fatty acids (PUFAs) represent a promising approach. The aim of this chapter is to summarize t…

Effect of different antioxidants in experimental alcoholic optic neuropathy

2008

Purpose To establish the possible beneficial effects of three synthetic antioxidants: S-adenosil-L-methionine (SAMe), N-acetyl-L-cysteine (NAC) and Ebselen in optic nerve damage following chronic ethanol feeding in adult rats. Methods Twenty male Sprague-Dawley rats (five groups of four animals each) were fed a liquid, ethanol-containing diet with littermates given isocaloric amounts of ethanol-free diet serving as controls. Antioxidants were administered by dissolving them in the liquid diet at 0.4 mg/ml (SAMe), 0.163 mg/ml (NAC) and 5.33 mg/ml (Ebselen). After 6 weeks, optic nerves were obtained and parameters that are relevant for the modulation of oxidative stress, such as antioxidants …