View clinical trials related to Optic Neuropathy, Ischemic.
Filter by:This series aims at studying the peripapillary and macular vascular changes in subjects with unilateral anterior ischemic optic neuropathy via Optical Coherence Tomography Angiography (OCTA).
The investigators tested the hypothesis whether the treatment with Citicoline in oral solution (OS-Citicoline) would increase or stabilize visual acuity, retinal ganglion cells (RGCs) function and neural conduction along the visual pathways (neuroenhancement), and/or induce preservation of RGCs fibers' loss (neuroprotection) in an human model of neurodegeneration: non-arteritic ischemic optic neuropathy (NAION).
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.
Clinical trial.gov Brief summary : Non-arteritic anterior ischemic optic neuropathy (NAION) is an optic neuropathy due to acute or subacute ischemic event of anterior optic nerve axons retrolaminar part that was vascularized by posterior ciliary brevis artery. The incidence of ischemia will be followed by axonal edema and causing compartment syndrome and heighten the incidence of ischemic. In NAION, the main pathology occurs at the level of the optical nerve, the axons of retinal ganglion cells. Initial damage is on the optic disc ischemia resulting hypoxic injury of axons and manifest as disc edema. Axonal edema cause disturbances of retrograde axonal transport of neurotrophic factors, especially brain derived neurotrophic factor, to the retinal ganglion cells. This will trigger a secondary toxicity and apoptosis. In addition, the presence of oxidative stress, calcium influx and mitochondrial damage will also triggers apoptosis. After the apoptosis of retinal ganglion cells, there was a thinning of the retinal nerve fiber layer (RNFL) through Wallerian degeneration. Thinning of the RNFL will manifest as visual field defects and the decline in visual acuity in patients with chronic phase NAION. Though NAION include disease entity that has long existed, but until now, there has been no evidence-based study on medical or surgical procedures that is effective enough to overcome NAION. The main treatment is to manage the risk factor such as hypertension, dyslipidemia, diabetes mellitus, hypercoagulable state. In general, if the patient is in the acute phase (edema of optic nerve head), methylprednisolone administration may be considered, but if the patient is already on chronic phase (atrophy disc) which generally occurs 6-11 weeks after the onset, then steroids are no longer indicated. Neuroprotective agent was considered as treatment in NAION given primary pathology NAION is the retinal ganglion cell axons. Among the various neuroprotective substance, Citidine diphosphocoline (CDP-choline 5'-diphosphocholine or Citicoline) is a therapeutic option NAION. Citicoline is an endogenous mononucleotide consisting of ribose, cytosine, pyrophosphate, and choline. Citicoline is a component intermediates in the synthesis of phospholipids in cell membranes, ie phosphatidylcholine. Exogenous citicoline administered orally or intravenously, will be split into citidine and choline. Citicoline via oral administration can be absorbed completely and have a similar bioavailability in the blood compared to parenteral administration such as intravenous. Once absorbed, citicoline will be distributed throughout the body and enter the blood-brain barrier and the blood retinal barrier penetrate into the central nervous system. If there is damage to neurons, exogenous citicoline will participate in the synthesis of phospholipids in the neuronal cell membrane. Some studies show that citicoline may have a neuroprotective effect on retinal ganglion cells and supporting regeneration of damaged neurons in vitro. Previous research on the citicoline effect in chronic phase NAION give satisfactory results. Dopaminergic neurotransmitter systems known to occur in vast numbers in the retina and post-retinal visual pathway. Retinal ganglion cells using certain subtypes of dopamine as a means of communication with the visual cortex. Rejdak et al in animal models showed that citicoline administration could improve and strengthen the dopamine transmission in the retina. Citicoline also a safe medicine, without serious adverse effect. Electroretinogram (ERG) is a tool to measure the function of the retina. ERG examination can measure electrical changes in the retina after light stimulus. ERG examination that can detect changes in the activity of retinal ganglion cell is a pattern ERG. Spectral-domain optical coherence tomography is a tool that can measure the thickness of retinal ganglion cells. Thinning of the RNFL will manifest as visual field defects in patients with NAION. The typical visual field defects of NAION is altitudinal defects associated with segmental edema optic nerve head. Based on these descriptions question arises whether the citicoline supplementation can repair damage to the neurons of the retina, especially the retinal ganglion cells, in NAION resulting in improved retinal function which can be judged from the improvement of the value of the amplitude of the wave of P50 and N95 in the examination pattern ERG (PERG) when compared with placebo ? In addition whether citicoline supplementation can increase the thickness of retinal ganglion cells assessed using SD-OCT? Does citicoline supplementation give the effect of improving visual field defects in patients with NAION?
The study objectives are to assess any changes in visual acuity and visual field observed following the administration of RPh201 during an overall treatment period of at least 13 consecutive weeks with an option to extended the treatment phase to another 13 weeks (26 weeks total), and at the follow-up visit at 3 month after end of treatment in patients with optic nerve neuropathy.
Transcorneal Electrical Stimulation (TES) using the "OkuStim®" device delivers electrical impulses to damaged and/or diseased photoreceptor cells. This electric stimulation of the retina may help to preserve visual acuity and/or the visual field.
Determine whether dalfampridine (Ampyra) can improve visual function in patients who have had nonarteritic ischemic optic neuropathy (NAION) with stable visual impairment.
This present research project intends to collect five quantitative test series: - perimetric examination using static stimuli, assessing the entire (80 degree) visual field with a fast thresholding algorithm (GATE) [Schiefer 2008] to know the extent/ magnitude of the visual field defect and its variability within the cohort and over time - D-BCVA, using FrACT [Bach 2007] and EDTRS chart [Ferris 1982] - RAPD (using swinging flashlight test). - IOP (using applanation tonometer) - RNFT and RNFV using Spectralis OCT (star scan, ring scan 2,8 mm, and volume scan) Optic disk morphology will be documented by fundus photography. This assessment of the above-mentioned data is needed in order to allow for estimation of the spontaneous course / fluctuation of the (quantified) functional and morphometric parameters of the N-AION patients during the follow-up period. This is essential for the estimation of the sample size of the subsequently intended SINN study, that is intended to compare different therapeutic strategies in N-AION patients.
Ciliary Neurotrophic Factor (CNTF) has been demonstrated in multiple preclinical models to enhance survival and regeneration of retinal ganglion cells, the retinal neurons injured in diseases like ischemic optic neuropathy/optic nerve stroke. We hypothesize that CNTF delivery to the human eye will provide neuroprotection (prevent loss of vision) and neuroenhancement (improve vision indices) in ischemic optic neuropathy. Patients in the trial will receive an NT-501 CNTF implant (made by Neurotech) into one eye, and will be carefully followed to evaluate safety and efficacy.
The objectives of this study were to: (1) evaluate the natural history of non-arteritic anterior ischemic optic neuropathy (NAION); (2) estimate the population incidence of NAION; and (3) identify potential risk factors for NAION.