View clinical trials related to Normal Tension Glaucoma.
Filter by:Clinical features, optical coherence tomography findings and surgical outcome in eyes with macular retinoschisis and detachment with normal tension glaucoma but without optic disc pit or high myopia were evaluated.
Glaucoma is a leading cause of blindness worldwide, whose treatment - intraocular pressure lowering - is only partially effective in preventing disease progression. Accordingly, other variables, such as ocular blood flow-related factors, have been implicated in disease pathogenesis. However, most findings involving vascular variables come from partial, small-scale studies. Furthermore, recent technological advances have identified a number of ocular blood flow variables that have yet to be tested in large scale trials. Therefore, a study that specifically aims at uncovering the role of vascular aspects in glaucoma is needed. For this purpose, a cross-sectional, observational case-control study will be conducted in the University Hospitals Leuven. This will be the largest-yet study on the subject, involving more than 750 patients. This will allow the creation of a specific cohort of patients where the vascular aspects are thought to be particularly important (low-tension glaucoma). It will use the largest combination yet of vascular-related measuring techniques (dynamic contour tonometry, optic coherent tomography, colour Doppler imaging and retinal oximetry)
Ocular blood flow has been consistently demonstrated to be altered in glaucoma patients when compared to otherwise healthy individuals. Numerous Doppler studies have shown a decrease in flow velocities in the retrobulbar arteries in what appears to be related to the degree of the glaucomatous disease. The anatomic pathway of the several arteries into the eye is intricately complicate, with at least one of them (the central retina artery) penetrating the optic nerve before entering the eye and supplying the innermost structures of the globe. As the optic nerve is surrounded by a layer of cerebrospinal fluid (CSF) which is in continuity with the rest of the central nervous system, this central retinal artery has also to cross this CSF containing compartment. Because of the intrinsic pressure this CSF - corresponding to the intracranial pressure at the orbital level - the possibility exists that this pressure around the optic disc could affect the blood flow of the arteries that go through it. The investigators will try to detect if a correlation exists between the optic nerve sheath diameter and the blood flow in the retrobulbar vessels of glaucoma patients.
Interplay between the increasing IOP and decreasing blood pressure (BP) during the 24-hour period, especially in the nocturnal period, may lead to insufficient perfusion pressure of the optic nerve and contribute to the glaucomatous damage in adjunct to the antero-posterior vectorial mechanical impact on the lamina cribrosa, the translaminar pressure. Patients with progressive VF loss showed greater nocturnal BP dips than patients with stable VF. Reduced mean intraocular perfusion pressure (IOPP) was significantly associated with the extent of glaucomatous damage. How the nycthemeral IOP fluctuation influences glaucoma progression has not been studied in a prospective manner and remains to be elucidated. The purpose of this study is to assess the relationship between the 24-hour IOP fluctuation pattern and the 24-hour BP pattern in patients with primary open angle glaucoma (POAG). IOP fluctuations will be monitored with SENSIMED Triggerfish®, a portable investigational device using a contact lens sensor that monitors the IOP fluctuation continuously over 24-hours.
The purpose of the study is to prove if there is any difference in the nerve fiber layer between patients with normal- and high-tension-glaucoma with similar structural optic nerve head parameters.
The primary purpose of this study is to determine whether topical ophthalmic anesthetics lower the intraocular pressure in the eye.
Evidence has accumulated that systemic and ocular mechanisms, responsible for regulating blood flow in the area of the optic disc, such as reduced ocular perfusion pressure, abnormal autoregulation and vascular dysregulation may be involved in the pathogenesis of normal tension glaucoma (NTG). Defective cardiovascular neuroregulation has been advocated as a possible one of the main systemic contributing factors in the etiology of NTG. Based on the results of previous studies, the hypothesis has been posed that patients with NTG have an impaired diurnal heart rate variability (HRV) or high activity of the sympathetic component of autonomic nervous system (ANS) and endothelial dysfunction. Impaired balance of ANS, resulting in increased demand for oxygen in the tissues and subsequent low threshold of hypoxia in all organs (including the eye) can be an important link in the pathogenetic pathway of NTG, making the optic nerve more sensitive to small and short-term changes in perfusion pressure and prone to damage even under a statistically "normal" intraocular pressure (IOP). The aim of this study is to evaluate the activity and characteristics of the following systems: the central ANS (through a 24-hour analysis of heart rate variability and blood pressure), peripheral vascular system (through the analysis of the post-occlusive hyperemia reaction within the distal part of left upper limb) and the local retrobulbar circulation as measured by color Doppler imaging (CDI) in patients with NTG and healthy volunteers. The correlations between all above systems, as well as between them and the structural and functional parameters of the optic nerve, and the retina in both groups will be also analyzed.
To prove the non-inferiority of the fixed timolol-dorzolamide combination (Cosopt) compared to 0.005% latanoprost (Xalatan) in the aspects of intraocular pressure (IOP) and ocular perfusion pressure (OPP) in subjects with normal tension glaucoma (NTG) Clinical hypotheses. Primary hypothesis - Cosopt group is non-inferior to Xalatan group in diurnal IOP reduction. Secondary hypothesis - Cosopt group is non-inferior to Xalatan group in diurnal diastolic and systolic OPP.
The objective of this study is to determine whether systemic blood pressure in the body is related to the development and progression of normal tension glaucoma in the eye. The study aims to clarify whether subjects with episodes of hypotension (low blood pressure) at night are at increased risk for sight loss and the development of normal tension glaucoma.
The purpose of this study is to evaluate whether systemic glutathione level is decreased in patients with normal tension glaucoma.