Active clinical trials for "Optic Nerve Diseases"

Ischemic optic neuropathy is among the most common causes of serious impaired vision in the middle-aged and elderly population in the western world. The current study focuses on a subgroup of ischemic optic neuropathy, the so-called non-arteritic ischemic optic neuropathy (NAION). Although the exact pathogenesis of NAION has not been fully clarified it is known that patients with cardio-vascular risk factors such as hypertension, diabetes mellitus and dyslipidemia have also an increased risk to develop NAION. Along this line of thought it has been shown that patients with a history of NAION in one eye have an increased risk to develop NAION also on the contralateral eye. However, clinical studies investigating ocular perfusion abnormalities in patients with NAION are sparse and even contradicting. Thus, the current study seeks to measure ocular blood flow parameters in patients with a history of NAION and compare it to healthy age-matched subjects.

Patients with multiple sclerosis (MS) may show chronic signs of optic neuropathy (CON) that may follow acute optic neuritis (secondary form of CON, S-CON) or occur independently of any acute demyelinating lesion of the optic nerve (primary form of CON, P-CON). In both S-CON and P-CON, a long term progressive ganglion cell axonal loss occurs. This axonal damage could be secondary to retrograde atrophy of axons within plaques of demyelination or a primary progressive degeneration of ganglion cells, but the underlying physiopathology has not been fully questioned in the different profile types of CON. In this project, investigators aim at understanding the pathophysiology of S-CON and P-CON, i.e. secondary to demyelination or primary degeneration, in patients complaining of persistent visual complaints. In a first cross sectional study, 30 MS patients with mild to moderate P-CPON or S-CON and 30 age-matched control subjects will perform an extensive neuro-ophthalmological assessment including clinical examination, visual evoked potentials (pattern and low contrast), electroretinogram (pattern and multifocal ERG), OCT (peripapillary and macular volume scan segmentation protocols) and MRI of the optic nerve. In these patients with mild to moderate CON, investigators aim at differentiating patients showing predominant demyelination from those showing pure or predominant axonal degeneration. Visual function assessment and degree of axonal degeneration will be compared and correlated in the two types of underlying pathophysiology and in the group of control subject. In a following longitudinal study, the patients will be re-assessed a year later in order to evaluate the progression of CON in both profile types. Our hypothesis would be that visual function and progression is worse in the degeneration group as compared to the demyelination group. This study should help to find reliable measures of the pathophysiology of CON and correlate it with the long-term visual prognostic of the disease.

The objective of this study will be to answer a clinical question that has not already been investigated; that is, what are the effects of aortic infra-renal clamping and unclamping on intraocular pressure during Abdominal Aortic Aneurysm (AAA) repair? Depending on the results, this study may raise or alleviate concern that vascular surgery for abdominal aortic aneurysm could contribute to early perioperative exacerbation of pre-existing eye disease and increase a patient's vulnerability to developing a type of blindness known as ischemic optic neuropathy. The purpose of this observational study is to evaluate whether intraocular pressure measurements with a handheld tonometer will detect changes in intraocular pressure related to intraoperative events during aortic cross clamping and unclamping that may provide information on causes of perioperative blindness.

This study plans to learn more about the thickness of the choroid in patients with optic neuropathy. The choroid is a layer of blood vessels that supplies oxygen and nourishment to the outer layers of the retina. Patients are being asked to be in this research study because they have optic neuropathy and are receiving care at the University of Colorado Hospital.

The participant is being asked to be a subject in this research study because the participant may have a disorder that can cause optic nerve damage and impairment of his/her visual function which is called optic neuropathies (ON). Optic neuropathy refers to damage to the optic nerve (a "cable" connecting the eyes and the brain to transmit the visual signals) due to any cause.In this study, the investigator is using magnetic resonance imaging (MRI) and ophthalmic measures such as optic coherent tomography(OCT), which are non-invasive imaging tests to measure the changes in eye globe shape ,the flow of blood and brain fluid. It is hoped that this study will provide new knowledge that may allow the investigator to better understand the cause of symptoms associated with optic neuropathy and ways to better monitor what is happening.

Thyroid associated ophthalmopathy (TAO) is a common autoimmune disorder. The pathogenesis of TAO is unclear, and studies found that T cell, B cell and monocytes, macrophages and mast cells are located in the orbital tissue of TAO. Dysthyroid optic neuropathy (DON) is the most serious complication of TAO, which can cause blurred vision, color vision and vision function damage, and affects the quality of life. Investigation of the therapeutic effect of orbital decompression may provide some clues to make the policy at treatment of DON. We explore the therapeutic effect of orbital decompression in patients with DON in both eyes.

The objective of the study is to determine whether administration of idebenone can shorten the time to improvement of visual acuity in patients with chronic vision loss due to LHON.

Aim: To develop a suitable radiation optic neuropathy (RON) diagnostic model based on optical coherence tomography angiography (OCTA) and to reveal the correlation between endocrine and OCTA indexes in nasopharyngeal carcinoma (NPC) patients with radiation encephalopathy (RE). Methods: This retrospective cross-sectional study included 80 male NPC patients with RE following radiotherapy (40 non-RON and 40RON). Endocrine and OCTA indexes were collected. The macular and peripapillary vessel density (VD) were automatically analyzed using AngioVue 2.0 of the RTVue XR Avanti device. The OCTA indexes were included in the multivariable binary logistic regression model between non-RON and RON. For all RE patients, a multiple linear regression was performed between each of the OCTA indexes and the endocrine indexes.

assessing the role of neuromuscular ultrasound in optic nerve involvement in systemic lupus patients.

This study is a multi-country retrospective and cross-sectional observational study of affected LHON subjects, based on retrospective subjects' medical chart abstractions and cross-sectional administration of patient-reported outcomes (PROs).