Active clinical trials for "Ocular Hypertension"

Prostaglandin analogs (PGAs) represent a new class of active ocular hypotensive agents and possess a unique mechanism of action. Many studies suggested that 0.005% Latanoprost was more effective and safer than other anti-glaucoma medications, such as beta-blockers. It has also been found to be more effective than other class of anti-glaucoma medications such as carbonic anhydrase inhibitors and alpha agonists. However data on such comparison is lacking in Chinese patients. So it is necessary to increase China experience and get clinical data from China. Besides latanoprost, brinzolamide is known as one of the other ocular hypotensive agents with less systemic adverse effects, therefore it is selected as the controlled medication of this study. The administration phase will be 4 weeks because it is long enough to compare both efficacy and safety of the study drugs and accounting for following-up conditions in China, it will be easier for the investigators to get enough subjects in a limited stage if the observation time is shorter. Before treatment with the study drugs, any previous glaucoma drugs will be washed out. The minimum washout periods are 5 days for cholinergic agonists, 1 week for adrenergic agonists, 3 weeks for adrenergic β receptor blockers and 4 weeks for PGAS. After washout, the patients will be randomised send to two parallel study groups: one group will receive latanoprost 0.005% once daily in the evening, the other group receive 1.0% Brinzolamide twice daily. Randomization will be obtained using a list of random numbers .During the study there will be four visits: screening, baseline, 2 weeks, and 4 weeks of treatment. The IOP will be measured with a Goldmann tonometer at 8 am for each visit. The tonometry will be performed before the administration of the dose of the day in patients treated with Brinzolamide. Three separate measurements will be taken for each eye and the mean of the three measurements will be used in the statistical analysis. Best corrected visual acuity and refraction will be determined and a slit lamp examination, ophthalmoscopy will be performed at all visits.

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.

Glaucoma is the first cause of irreversible blindness worldwide with more than 60 millions people affected in 2010. It is defined as a neurodegenerative disease characterized by a progressive loss of retinal ganglion cells (RGC), visual field deterioration and optic nerve excavation. Intraocular pressure (IOP) is the most common risk factor. Despite its severity, its impact on quality of life and an existing treatment that can delay visual field damages, there is no recommended strategy to screen the disease. Clinical evaluation of optic nerve head excavation performed either by ophthalmologists or glaucoma specialists is highly inter-observer dependent and limits its accuracy to diagnose glaucoma. Additionally, up to 30 to 40% of nerve fiber layer may be lost before detecting first visual field defects, thus making this tool not accurate enough for screening purposes. Spectral-Domain Optical coherence tomography (SD-OCT) imaging technology allows precise and reproducible measurements of optic nerve head structures and retinal layers mainly related to the speed of acquisition and an axial resolution of 5 microns. New SD-OCT parameters have been developed to improve its diagnostic accuracy for glaucoma disease. The investigators therefore investigate performances of SD-OCT to discriminate glaucoma patients and controls. All subjects will undergo SD-OCT imaging (Spectralis™ OCT, Version 6.3, Heidelberg Engineering, Germany) and other study procedures in one single visit. All examinations performed on the subjects are non-significant risk.

This is an open-label study in patients who are currently using either a topical prostaglandin as sole ocular hypotensive medical therapy q.d., or a topical prostaglandin plus an adjunctive topical ocular hypotensive marketed product either q.d., or b.i.d. in the same eye(s). Compliance will be measured over the two months of participation.

Early glaucomatous visual field changes can be missed with the routinely used Standard Automated Perimetry (SAP) and the 24-2 test pattern due to limited sampling of the central 10 degrees. While this shortcoming can be overcome with the addition of a 10-2 test, performing both tests places extra demand on the perimetric services (doubling test times) and patients. Smart Supra Perimetry (SSP) uses a new faster algorithm that can complete both 24-2 and 10-2 test patterns in a similar time frame to a single 24-2 SAP test. This comparative study aims to determine the sensitivity and specificity (i.e. diagnostic accuracy) of SSP in identifying early glaucomatous visual field loss. A sample of 100 patients with early/suspect glaucoma will undergo SAP 24-2 and 10-2 (SITA algorithm) using Humphrey visual field perimetry and SSP 24+10-2 using Henson 9000. Eyes will be categorised into 2 groups i.e., glaucoma and non-glaucoma, on the basis of structural changes to the disc as evaluated by the clinician. The sensitivity and specificity of the SAP and SSP tests will be established along with test duration. The size and location of defects established with both the SAP and SSP strategies will also be compared.

Continuous intraocular pressure (IOP) measurement with a contact lens sensor may provide more information on the drug-related IOP change than 24-hour IOP measurement with Goldmann applanation tonometry (GAT.

The purpose of this research study is to compare the effect of Netarsudil and Timolol on eye pressure and blood vessels of the back of the eye.

Both Cosopt® and Xalatan® plus Timoptic® will significantly lower IOP, however only Cosopt® will demonstrate positive hemodynamic effects. The clinical significance of this will be investigated by examining the ophthalmic and short posterior ciliary arteries to determine the blood supply to the optic nerve head, the site of damage in glaucoma

Background Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. The existence of an effective autoregulation in the optic nerve circulation has been shown in animals and humans. The exact mechanism behind this autoregulation is still unknown. The motive for the investigation of optic nerve head (ONH) blood flow autoregulation is to enhance the understanding of pathologic eye conditions associated with ocular vascular disorders. To clarify the regulatory mechanisms of ONH microcirculation is of critical importance to understand the pathophysiology of glaucoma, because there is evidence that glaucoma is associated with optic nerve head ischemia. Several studies indicate that a disturbed autoregulation might contribute to glaucomatous optic neuropathy. Currently, five classes of intraocular pressure (IOP) reducing drugs are available for topical therapy in patients with glaucoma or elevated intraocular pressure. These drugs have also vasoactive properties, which may influence both the resting ocular circulation and the autoregulatory mechanisms of blood flow during changes in ocular perfusion pressure. Study objective To investigate the influence of common topical glaucoma therapy on ONH blood flow regulation during changes in IOP and systemic arterial blood pressure.

In this study, participants will be imaged using two Optical Coherence Tomography (OCT) devices: device N, a standard conventional OCT device with an invention (comfortable chin and forehead rest that can be adjusted to fit each individual's size) attached to the device; and device C, the standard conventional OCT device with no invention attached. The investigators will assess whether the chin and forehead rest attachment (invention) provides a more comfortable experience for patients.