Active clinical trials for "Low Tension Glaucoma"

The purpose of this study is to assess how surgical interventions in glaucoma affect 24-hour intraocular pressure, 24-hour ocular perfusion pressure, optic nerve blood flow, and retinal oxygen saturation.

Glaucoma is among the leading causes for blindness in the western world. Elevated intraocular pressure (IOP) has been identified as the most important risk factor. However, some patients progress despite adequate IOP lowering while some subjects with elevated IOP never develop glaucoma. Other patients develop glaucoma although IOP measurements were always in the normal range. Therefore, other factors must be involved. In the last years, studies using MRI have been performed and evidence has accumulated that also changes in retrobulbar structures are present, in particular in the lateral geniculate nucleus and the visual cortex. However, these studies were limited by the low spatial resolution of the MRI instruments used. The investigators propose to overcome this problem by using an ultrahigh-field Magnetom 7T whole-body MR scanner (Siemens Medical, Germany) installed at the MR Centre of Excellence at the Medical University of Vienna. This scanner is equipped with a 32-channel head coil and the SC72 high-performance gradient system and is thus perfectly suited for structural and functional imaging. The aim of the present study is to investigate whether structural and functional parameters are altered in patients with primary open angle glaucoma (POAG), normal tension glaucoma (NTG), ocular hypertension (OHT) compared to healthy control subjects. The exact topographical survey of intracranial structures such as the LGN and the assessment of neuronal structures by DTI may allow for the better assessment of therapeutic responses to new neuroprotective agents.

Purpose To evaluate efficacy and safety of combigan(Brimonidine/Timolol) and 0.5% Timoptic (Timolol) ophthalmic solutions in normal tension glaucoma patients.

Glaucoma is the second leading cause of blindness worldwide. Literature shows increasing evidence that dysfunction of ocular microcirculation in the optic nerve influences the progression of glaucoma. It has been shown that flicker light-induced vasodilatation of retinal veins is diminished in patients with glaucoma. Also previous studies indicate that the blood flow autoregulation is impaired in patients with glaucoma. Therefor the ocular perfusion pressure can not be maintained stable during changes of the systemic arterial blood pressure. Laser speckle flowgraphy (LSFG) represents a non-invasive method to quantify ocular perfusion also at the ONH. LSFG enables noninvasive quantification of microcirculation of the optic disc in Japanese glaucoma patients. Study Objectives: To assess the changes in LSFG parameters in patients with normal tension glaucoma, compared to healthy subjects during flicker light stimulation and isometric exercises.

The purpose of this study is the investigation of biomechanical properties of the cornea using computer-aided data analysis. Currently, it is known that keratoconus and glaucoma are ocular disease that are associated with biomechanical alterations of the cornea. Corneal ectasia, especially keratoconus, is a corneal disease that leads to an irreversible loss of visual acuity while the cornea becomes steeper, thinner and irregular. For these patients, surgical intervention (e.g. corneal cross-linking) is performed, in case of disease progression. In glaucoma, the information about corneal alterations serves in two ways, first, correct measurement of intra ocular pressure (IOP); second, early diagnosis of suspects before visual field defects are detectable. Especially, the Corvis ST is an air-puff tonometer that measures intraocular pressure, corneal thickness (CCT) as well as dynamic corneal response (DCR) parameters. Most of the DCR parameters are affected by IOP and CCT: Therefore, algorithm are needed to determine parameters without impact of IOP and CCT that are describe the biomechanical properties of the cornea.

The primary purpose of this study is to determine whether topical ophthalmic anesthetics lower the intraocular pressure in the eye.

The main aim of this study is to determine the trans-laminal cribrosa pressure difference (TLCPD) for normal tension glaucoma (NTG) patients from the brain and the eye in supine, upright and minor head down tilt positions. It is also to investigate the venous drainage system in the same body positions.

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)

Globally primary open angle glaucoma (POAG) affects over 60 million people. The exact pathogenesis of POAG is poorly understood. A significant risk factor for glaucoma is advancing age. The rate of ageing is not the same in all age matched individuals. The concept of accelerated ageing suggests that the presence of a number of specific genetic, environmental or systemic risk factors may cumulate to accelerate the ageing process in some individuals and lead to the development of age-related disease. Understanding the factors that influence accelerated ageing is vital. Advanced glycation end products (AGEs) are a complex group of compounds that are naturally formed. They accumulate gradually with age in cells, tissues and blood vessels throughout the body where they adversely affect structure and function. Circulating AGE levels can be influenced by oxidative stress levels and dietary intake. Recent research has found that sustained exposure to high levels of circulating AGEs could be a major factor in the development of a number of chronic age-related degenerative disorders, including POAG. To date there have been few clinical studies that have been able to non-invasively explore the association between AGE levels and the development and progression of glaucomatous optic neuropathy (GON), or to explore the possible contribution that oxidative stress and dietary intake make to total tissue AGE levels in such patients. Furthermore little is understood about the relationship between AGE levels and retinal vascular function, a parameter known to be altered in GON that also could be influenced by AGE levels. The proposed study will aim to evaluate whether tissue-bound AGE levels are associated with parameters of retinal vascular function, oxidative stress, dietary intake and the presence of GON. Establishing this association could increase our understanding of the pathogenesis of GON and allow a new biomarker for accelerated ocular ageing to be realised

Purpose: To analyze the relationship between normal-tension glaucoma (NTG) and serum bilirubin levels. Materials and Methods: This research included 38 patients with NTG and 38 healthy controls with similar age and sex distribution, for a total of 76 subjects. Serum samples were taken from all of the subjects, direct serum bilirubin, indirect serum bilirubin and the total serum bilirubin were measured.