View clinical trials related to Low Tension Glaucoma.
Filter by:Purpose To evaluate efficacy and safety of combigan(Brimonidine/Timolol) and 0.5% Timoptic (Timolol) ophthalmic solutions in normal tension glaucoma patients.
Retinal ischemia is thought to play an important role in the pathogenesis of glaucoma. Up until today, very little is known about the metabolic alterations in the retina of glaucoma patients, since only techniques for surrogate measurements of metabolism (like blood flow velocities and vessel diameter) were available. Oximetry has provided us with an important tool to study metabolism in glaucoma, and to correlate these findings with the available blood flow evaluation techniques. Preliminary results by the group of Prof Stefánsson (2011) with the dual wavelength oximeter pointed out that deeper glaucomatous visual field defects are associated with decreased arteriovenous differences in retinal oxygen saturation. These data suggest that a change in oxygen metabolism occurs in glaucomatous retina. This reduced oxygen metabolism may be related to tissue atrophy. However, this explanation is still hypothetical, since the relation between these oximetry results and structural changes in the optic nerve have not been studied yet. 1. What are the oximetry values in a normal population of within the same age group as the glaucoma population? To answer this question, a normative database of the investigators retinal oximetry device needs to be constructed for healthy controls. 2. Do glaucoma patients have different retinal oximetry values than these normal patients? Are there any differences in retinal oxygenation between these glaucoma groups? To answer these questions, oximetry measurements will be performed in patients with normal tension glaucoma (NTG) and primary open angle glaucoma (POAG). 3. Is there an association between structural optic disc and retinal nerve fibre layer changes, using Heidelberg Retinal Tomography (HRT), with alterations in retinal vascular oxygen saturation in NTG and POAG patients? 4. Are blood flow measurements, using colour Doppler imaging (CDI), correlated with alteration in retinal vascular oxygen in NTG and POAG patients?
The primary purpose of this study is to determine whether topical ophthalmic anesthetics lower the intraocular pressure in the eye.
The purpose of this study is to assess the long-term efficacy and safety of latanoprost monotherapy in patients with normal tension glaucoma (NTG) using a prospective, observational design. Visits were scheduled at 6-month intervals for 24 months. Intraocular pressure (IOP), optic nerve head findings, visual field status, and adverse events were recorded.
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 investigators have completed a study in which the investigators examined the response of the retinal circulation to changes in posture from sitting to lying down in patients with Normal Tension Glaucoma (NTG). This alteration in position produces changes in the local blood pressure at the entrance to the retinal vasculature. In a healthy retina, the vasculature adapts by dilating and constricting in order to maintain a steady blood flow rate. In an eye with NTG, this often does not occur. Upon analysis at the completion of the study , the investigators found that the patients who had been taking Alphagan (brimonidine) during the study did not exhibit the blood flow increases typical of NTG while lying down; instead, they maintained a steady blood flow rate as did the group of healthy control subjects. The investigators primary objective is to now demonstrate in a prospective study that Alphagan can restore retinal vascular autoregulatory function in patients with NTG who do not autoregulate. The investigators will also determine the effect of Alphagan treatment on the patients' ability to detect motion.
A study to evaluate the effect of the 12-week treatment with timolol/dorzolamide combination eyedrops (COSOPT) on decrease in intraocular pressure (IOP) at 2 hours after the study drug administration
since glaucoma is considered an optic neuropathy, new treatments for glaucoma are being continuously investigated, including neuroprotection. Previous studies implied that phenytoin, a potent anti-convulsive drug, has a neuroprotective role, and Na+ channels blockage was suggested as a possible mechanism. This study predicts that glaucoma patients taking Phenytoin will have a less advanced glaucoma as compared to patients not taking the drug. Glaucoma severity will be determined by visual acuity, visual fields, optic disc cupping and nerve fiber layer thickness
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.