View clinical trials related to Low Tension Glaucoma.
Filter by:The purpose of this study is to assess whether deep sclerectomy is as effective in lowering intraocular pressure (IOP) as trabeculectomy in patients with normal tension glaucoma.
This study is for patients have been using prostaglandin analogue eye drops with a preservative for 3 months or more and have been diagnosed with prostaglandin-associated peri-orbital disease. the investigators would like to confirm the real world evidence(RWE) of safety and efficacy after changing to Eybelis ophthalmic solution 0.002%.
The purpose of this study is to assess whether endoscopic cyclophotocoagulation added to cataract surgery lowers intraocular pressure more than cataract surgery alone in patients with normal tension glaucoma.
Glaucoma is characterized by a progressive loss of retinal ganglion cells (RGCs) leading to optic nerve head (ONH) damage and associated visual field defects. The main risk factor for glaucoma is elevated intraocular pressure (IOP). Reducing IOP slows down the progression of the disease as several large multicenter trials have shown. Some patients, however, still progress despite adequately controlled IOP. As such, there is considerable interest in approaches that rescue RGCs independent of IOP, a strategy called neuroprotection. Although this field was actively discovered in the last 20 years in the brain and the eye, no non-IOP related treatment is clinically available to date. Various approaches are currently studied in some detail. One interesting strategy focuses on the neurovascular unit. The blood flow of the human retina is controlled by complex mechanisms that include myogenic, metabolic and hormonal factors. The high consumption of oxygen in the human retina is crucial for normal functioning of the organ. As in the brain, blood flow in the retina is also controlled by neurovascular coupling. This means that the retina increases its blood flow to regions in which neurons are activated. This is done in an effort to provide more oxygen and glucose to the active neurons. In the recent years evidence has accumulated that astrocytes play a key role in mediating this vasodilator signal. In the brain, abnormalities in neurovascular coupling have been observed in diseases like stroke, hypertension, spinal-cord injury and Alzheimer's disease. This break-down of neurovascular coupling is considered to play a key role in neuronal death in these diseases. In the retina, abnormalities in neurovascular coupling have been observed in diseases as diabetes and glaucoma. Most of the data obtained in the human retina stem from a system that measures retinal vasodilatation during stimulation with flickering light. The investigators have previously shown that flicker stimulation of the retina is, however, also associated with a pronounced increase in retinal blood velocities. In this study the investigators employed laser Doppler velocimetry (LDV) for the measurement of retinal blood velocities, but this technique is not clinically applicable because it requires excellent fixation of the subject under study. In the present study, the investigators propose to use an alternative system for neurovascular coupling that they have developed recently. In this approach, the investigators use bi-directional Fourier-domain optical coherence tomography for the assessment of retinal blood flow. Optical coherence tomography (OCT) is a non-invasive optical imaging modality enabling cross-sectional tomographic in vivo visualization of internal microstructure in biological systems. In ophthalmology, OCT has become a standard tool in visualizing the retina and nowadays is considered also as a standard tool in the diagnosis of retinal disease. In the recent years, conventional time domain OCT was replaced by Fourier domain OCT providing significantly improved signal quality. This bidirectional system overcomes the limitations of previously realized techniques, which include doubtful validity and limited reproducibility. In addition, pattern ERG, multifocal ERG and oscillatory potentials will be measured to allow for concomitant assessment of neural function. The investigators seek to measure neurovascular coupling in the human retina in patients with early primary open angle glaucoma (POAG), normal tension glaucoma, ocular hypertension and a healthy control group. In order to obtain information on neurovascular coupling, both neuronal function as well as retinal blood flow need to be measured. In the present study, the investigators will employ pattern ERG, multifocal ERG as well as oscillatory potentials to assess the function of the inner retina. Retinal blood flow through major retinal arterial and venous branch vessels will be measured before, during and after flicker stimulation with the dual-beam bidirectional Fourier Domain Doppler OCT coupled to the commercially available Dynamic Vessel Analyzer (DVA) produced by IMEDOS, Jena, Germany, which provides adequate resolution to study the retinal circulation.
The purpose of this study is to evaluate the effect of Ginkgo biloba extract (GBE) on the number of blood vessels in the back of the eye as well as the amount of blood flow at the nailfold(where the fingernail meets the skin) of the 4th finger in the hand.This finger, along with the 5th finger, has the most transparent skin, which makes imaging a little easier. GBE is an over-the-counter pill, made from a natural powder taken from the Gingko (Maidenhair) tree, that is widely used. A technique called Optical Coherence Tomography Angiography (OCTA),will be used to measure the small blood vessels at the back of the eye, the macula (the area of sharpest vision), and the optic disc (the point at which the nerve fibers from the retina enter to form the optic nerve, which transmits visual impulses to the brain).
Metabolomics consists in the study of metabolites in body fluids or tissues. It investigates the consequences of the activity of genes and proteins. One of its advantages is that it is able to do a simultaneous measurement of metabolic changes in living organisms as a response to a disturbance (disease, diet, environment, others) and because a metabolic profile is summative of all the biochemical processes occurring in the body at a given time, it makes no presumption about the relative importance of these processes. Ultimately it is a fingerprint of the organism's health status, at a given time. Metabolomic analysis of serum, plasma and urine has revealed panels of metabolites that distinguish patients with cardiovascular disease, breast cancer, Parkinson disease, Alzheimer's disease and diabetes from control patients. Regarding ocular diseases only few studies have been published, related to diabetic retinopathy, retinal detachment, age-related macular degeneration, uveitis and glaucoma. Glaucoma is one of the leading causes of blindness in the world, according to the World Health Organization, and there are still no biomarkers that can provide an early diagnosis. Nowadays, glaucoma classification relies substantially in the measurement of intraocular pressure (IOP), which can be rather artificial and also unreliable since IOP values can fluctuate during the day. Moreover, patients with normal IOP values can also develop glaucomatous neuropathy (normal-tension glaucoma, NTG) and progress even when IOP is decreased. Several studies have shown that NTG patients suffer from a systemic vascular dysregulation, with higher rates of systemic hypotension, Raynaud phenomenon and migraine. Hence, other mechanisms than an increased IOP are of importance in the development and progression of glaucoma. Only one metabolome-wide study has been made in glaucoma (Burgess, I.; 2015). In a sample of 72 american patients with primary open angle glaucoma (POAG), the authors found significant differences in comparison to controls. The hypothesis for this study is that glaucoma patients will differ from controls, and POAG patients will differ from NTG patients. The investigators will look into metabolomics as a way to create a method to diagnose and stratify patients, as an add-on or alternative to the currently available diagnostic tools like IOP, functional and structural measurement.
To assure the quality of follow-up and treatment, data of glaucoma patients are stored and evaluated after anonymisation.
Retinal ischemia is thought to play an important role in the pathogenesis of glaucoma. Recent findings have confirmed that there is a direct correlation between the levels of venous oxygen saturation and the degree of the glaucomatous disease, presumably due to a decrease in retinal cell metabolism. However, glaucoma patients have been suggested to have a different pattern in retinal venous circulation. For instance, the observation of a visible pulsating central retinal vein is a phenomenon that can be seen in up to 98% of the healthy individuals but is identifiable in less than 50% of glaucoma patients. While the nature of these venous changes are not year clear, the lack of a visible pulsating flow could suggest an increased intraluminal venous pressure due to some obstruction from both ocular or extraocular structures. This undetermined increase in venous pulse pressure could then significantly decrease perfusion pressures and therefore further decrease oxygen supply to the retinal tissues. The investigators will therefore try to determine if there is a significant difference between the oxygen saturation of the retinal vessels in both glaucoma patients with and without a visible pulsating central vein
Purpose To evaluate efficacy and safety of combigan(Brimonidine/Timolol) and 0.5% Timoptic (Timolol) ophthalmic solutions in normal tension glaucoma patients.
To obtain demographic and baseline ophthalmic parameters (such as Intraocular Pressure profiles, disc morphological characteristics, central corneal thickness, peripapillary retinal nerve fibre layer thickness and its serial changes, visual field changes, severity of any medical associations—e.g. hypertension, migraine, strokes, silent cerebral infarcts) with non-invasive measurements, in Chinese Patients with Normal Tension Glaucoma