View clinical trials related to Open-Angle Glaucoma.
Filter by:Glaucoma remains a disease with an unclear and complex underlying pathophysiology. Recently, researchers have emphasized not only intraocular pressure (IOP) or vascular dysregulation, but also translaminar pressure's (TPG) role in glaucoma (TPG=IOP-ICP). A higher TPG may lead to abnormal function and optic nerve damage due to changes in axonal transportation, deformation of the lamina cribrosa, altered blood flow, or a combination thereof leading to glaucomatous damage. However only invasive ICP measurements are available within the contemporary medicine. The ideas for non-invasive ICP measurement have been approached since about 1980. Most of the proposed technologies were based on ultrasound and were capable of monitoring blood flow in intracranial or intraocular vessels, cranium diameter, or acoustic properties of the cranium. Broad research has extended into sonography of optic nerve sheath and its relation with elevated ICP. However, most of these correlation-based methods had the same problem—the need of individual patient specific calibration. Seeking to measure absolute ICP values, researchers from Kaunas University of Technology created a non-invasive method, which does not need a patient specific calibration. The method is based on direct comparison of ICP value with the value of pressure Pe that is externally applied to the tissues surrounding the eyeball. Intracranial segment of ophthalmic artery (OA) is used as a natural sensor of ICP and extracranial segment of OA is used as a sensor of Pe. The special two depth transcranial Doppler (TCD) device is used as a pressure balance indicator when ICP = Pe. The aim of our study is to assess TPG in patients with primary open open-angle glaucoma (POAG). In addition the investigators want to measure ICP in patients with papilledema (PE) in order to compare them with glaucoma patients.
Glaucoma is an optic neuropathy in which the main risk factor is intraocular pressure (IOP). The search for other variables involved in glaucoma pathogenesis and progression has identified both systemic and ocular signs of vascular dysfunction in glaucoma patients, such as migraine, peripheral vasospasm, systemic hypotension and cerebral microvascular ischemia. Ocular blood flow studies using Color Doppler Imaging (CDI) technology has demonstrated blood velocities and increased vascular resistance (RI) to exist in such patients when compared to healthy controls. However, a CDI examination provides far more additional information, such as arterial pulsatility (PI) and mean blood velocities (MFV). While these have been used for decades now to study cerebral arteries vasoreactivity, little is known about how these variables are changed in glaucoma patients. We have recently demonstrated that these variables can be used to identify a change in the normal vascular activity when there is increased resistance. In glaucoma patients, a cutpoint in RI of the retrobulbar arteries could be determined beyond which PI increased significantly. This sharp increase in the PI has been used as an indirect signal that the vessel's ability to buffer a decreased perfusion pressure has been surpassed. The normal response to a decreased perfusion in a vascular territory with autoregulation is an increase in dilation in the downstream microcirculation, increasing cross section area in an attempt to keep a steady MFV. As PI is calculated using the vessel's MFV [PI = (PSV-EDV)/MFV], it is highly sensitive to changes in this variable. As such, the cutpoints we have identified in glaucoma patients are therefore an indirect assessment of the vessel's autoregulation limit. While our data could provide the rational as to why these RI values are associated with progression, the clinical question arises as to whether these cutpoints can be modulated by topical glaucoma therapy. As some medications such as carbonic anhydrase inhibitors have been found to have a positive effect in disease progression in what appears to be a non-IOP related effect, we considered the hypothesis that these drugs could have a positive impact on the ocular's microcirculation vasoactive response, potentially enabling to keep a steady MFV into higher values of vascular resistance.
To investigate the effect of patterned laser trabeculoplasty (PLT) compared to selective laser trabeculoplasty (SLT) on intraocular pressure (IOP) in treatment naiv patients suffering from open-angle glaucoma or ocular hypertension. Values for IOP will be measured at baseline, 1 day and 1 month post-interventional as well as 2, 3, 6, 9, 12, 18 and 24 months after treatment. - Trial with medical device
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
It is a comparative study of Safety and Efficacy of Canaloplasty and Non-penetrating Deep Sclerectomy Combined With Phacoemulsification to Treat Glaucoma and Cataract. It is a Randomised, Prospective Study.
The aim of this prospective randomized study is to investigate the efficacy and safety of trabeculectomy with ologen Collagen Matrix versus trabeculectomy using mitomycin C (MMC) in patients with medically uncontrolled open angle glaucoma.
WHAT IS THIS STUDY ABOUT? Glaucoma and ocular hypertension are chronic eye diseases that can damage the optic nerve and lead to vision loss or blindness. The optic nerve acts like an electric cable with over a million wires. This nerve is responsible for carrying images from the eye to the brain. The way glaucoma and ocular hypertension cause blindness depends on many factors, but the most important factor is the increased pressure inside the eye (intraocular pressure). There is no cure for glaucoma or ocular hypertension. However, lowering the pressure inside the eye has been shown to slow the progression of disease. Intraocular pressure can be lowered by glaucoma medication, laser treatment, or surgery. You have open angle glaucoma, pseudoexfoliative glaucoma, or ocular hypertension. Researchers want to find out more about how 2 drugs called Cosopt (dorzolamide hydrochloride and timolol maleate) and Xalatan (latanoprost) can help people with these conditions. Cosopt and Xalatan are both eye drops that are approved by the U.S. Food and Drug Administration (FDA) to reduce intraocular pressure in people with open angle glaucoma and ocular hypertension. The study doctor will do a laser procedure called Selective Laser Trabeculoplasty (SLT) on people in this study to help lower their intraocular pressure. The FDA has approved SLT to treat open angle glaucoma and ocular hypertension. Then the study doctor will ask some participants to use either Cosopt or Xalatan, if their intraocular pressure is still too high 4 to 6 weeks after the SLT procedure. The study doctor wants to see which of the 2 study drugs (Cosopt or Xalatan) is better at reducing intraocular pressure after SLT. It is planned that about 30 people with glaucoma or ocular hypertension who are at least 18 years old will be in this study. Out of the participants whose intraocular pressure is still too high after SLT, half will use Cosopt and half will use Xalatan. You do not have to be in this study to have SLT or to use Cosopt or Xalatan.