CoQun Study - (COQUN): a Study to Evaluate the Effects of CoQun in Patients Affected by Open-angle...
Open Angle GlaucomaThis is a randomized, parallel arm, multicenter, double-blind trial. Patients with POAG will be randomized 1:1 ratio to receive: Prostaglandin analogue (PGA) monotherapy + CoQun® (Arm A) Prostaglandin analogue (PGA) monotherapy + Vehicle (Arm B)
The in Vivo Effect of Medical and Surgical Glaucoma Treatments on the Schlemm's Canal Micro-structure...
GlaucomaCataractThe purpose of our current series of studies is to evaluate different glaucoma treatments in vivo effect on the conventional outflow pathway, and specifically on the Schlemm's canal (SC) anatomy using Enhanced Depth Imaging (EDI)-optical coherence tomography (OCT) . The images will be taken as part of the patients routine medical follow up (before starting the treatment, and 1,4 and 12 weeks afterwards) diameter, cross-sectional area and volume will be measured using commercially available 3-dimensional reconstruction. The series of studies will be divided into 3 branches, each branch contains different treatments.For each treatment different patients will be recruited. The branches are as following- The surgical branch- Before and after trabeculotomy Before and after cataract surgery Before and after vitrectomy surgery Before and after XEN™ Gel Stent implant The pharmacological branch- Before and during the treatment with prostaglandins analogs Before and during the treatment with alpha blockers Before and during the treatment with beta blockers Before and during the treatment with carbonic anhydrase inhibitor The laser branch- Before and after trabeculoplasty Before and after laser iridotomy Before and after yag capsulotomy laser
Analysis of Aqueous and Vitreous Humor
Proliferative Diabetic RetinopathyMacular Degeneration2 moreClinical Retina research studies often collect aqueous samples in hopes of estimating levels of drug or cytokines in the vitreous. Little is known about how well vitreous and aqueous correlate. This study will collect vitreous and aqueous samples at the same time to evaluate and compare drug and cytokine levels. The overall objective of this study is to evaluate the molecular concentration of growth factors, cytokines and chemokines in human aqueous humor and vitreous samples collected from individuals undergoing pars plana vitrectomy for tractional retinal detachment secondary to proliferative diabetic retinopathy, exudative or tractional retinal detachment secondary to macular degeneration, macular hole or neovascular glaucoma.
Impact of Timolol/Dorzolamide Therapy on Autoregulation in Glaucoma Patients
Open Angle GlaucomaGlaucoma 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.
The Laser in Pseudoexfoliation (LIP) Study
GlaucomaA number of large clinical trials have found pseudoexfoliation (PXF) to be a major risk factor for glaucoma progression and risk of blindness. It is estimated that PXF accounts for approximately a quarter of cases of open angle glaucoma in Nova Scotia, Canada, making this region an ideal setting for studying patients with this condition. Despite associated high morbidity, the treatment of pseudoexfoliative glaucoma remains suboptimal and a challenge for the clinician. Topical medical therapy is less effective than for primary open angle glaucoma and patients often require early surgical therapy, with associated risks. Selective laser trabeculoplasty (SLT) may be a safe and effective treatment for pseudoexfoliative glaucoma, although the evidence for this is presently lacking. The aim of the current study is to provide the first controlled-trial evidence for the effectiveness of SLT, compared to topical therapy, in the management of pseudoexfoliative glaucoma.
Anterior Segment Changes by Optical Coherence Tomography (OCT) in Phaco- Trabeculectomy
Angle Closure GlaucomaGlaucoma1 moreDevelop a measurement protocol by OCT imaging and characterization of the anterior chamber change in glaucoma patients before and after surgery. Show the effect of combined surgery in control of intra ocular pressure.
Use of Bevacizumab to Modulate the Outcomes of Trabeculectomy Surgery
GlaucomaVascular epithelial growth factor (VEGF) plays a critical role in vessel growth and wound healing. Bevacizumab, a non specific VEGF inhibitor, has been successfully used for the treatment of eye diseases associated with neovascularization. The purpose of this randomized study is 1) to investigate the effects of intraoperative subtenon injection of bevacizumab on the outcomes of trabeculectomy surgery. 2) to measure plasma and aqueous levels of VEGF and assess its association with the outcomes of trabeculectomy surgery. Trabeculectomy surgery, where a small drainage canal is created at the front of the eye, is the most common glaucoma surgery performed worldwide. The goal of the surgery is to control intraocular pressure. Failure of this procedure is most commonly caused by excessive scarring of the surgical site. If scarring occurs, the drainage canal can close. By adding Bevacizumab at the time of surgery, wound healing may be slowed and surgical failure prevented. The results of this study will be helpful in the future development of new more effective and safe surgical techniques for treatment of glaucoma. Patients who have given informed consent are randomized into two groups. One group receives standard of care for trabeculectomy surgery and the other group receives standard of care plus an injection of Bevacizumab at the surgery site. Both groups have a one time collection of ocular fluid and a blood sample taken from a vein in the arm. After surgery, patients are seen by their study doctor six times in the following year. At these visits measurements are taken of their visual acuity, eye pressure and blood pressure. The doctor does a clinical exam and at months six and twelve photographs of the patients' eye are taken.
Study of Ocular Blood Flow in Patients With Glaucoma and/or Obstructive Sleep Apnea Syndrome (OSAS)...
Obstructive Sleep Apnea SyndromeObstructive sleep apnea syndrome (OSAS) is a common disease, with a prevalence evaluated between 5 - 7% in the general population. OSAS is characterized by recurrent episodes of partial or complete upper airway obstruction during sleep, which are nearly systematically associated with a desaturation-reoxygenation sequence, an admitted detrimental stimulus for the cardiovascular system. It has now been demonstrated that OSAS per se is able to generate hypertension, atherosclerosis and autonomic dysfunction (high sympathic tone and increase in baseline heart rate), all conditions possibly interacting with ocular vascular regulation. OSAS has major consequences on the ocular level since it is associated with a higher frequency of optic neuropathies, such as glaucoma and nonarteritic ischemic optic neuropathy (NAION), both with functional severe prognosis. Most of vascular changes associated with OSAS have been studied at the level of macrovasculature. In terms of physiopathology, the main effects on the vascular system in OSAS are sympathetic hyperactivity, oxidative stress, development of endothelial dysfunction, systemic inflammation and metabolic alterations such as the appearance of insulin resistance. All these mechanisms can affect the microcirculation of the eye, especially the optic nerve and choroid. Our hypothesis is that the eye microvasculature is affected by OSAS, and these lesions may be detected via a reduced autoregulation of blood flow in humans. This project aims to demonstrate, quantify, and analyze the vascular modifications of the eye associated with OSAS trough a comparative clinical study on glaucoma patients and OSAS patients and matched healthy subjects for the regulation of the eye blood flow using confocal laser Doppler flowmetry (LDF). The regulation of the ocular blood flow will be assessed using several stimuli and measured using a new confocal LDF.
Development and Implementation of an Educational Program to Enhance Adherence to Glaucoma Treatment...
GlaucomaThis study evaluates the addition of an educational intervention program in order to improve medication adherence in glaucoma patients. Half of the participants will receive the educational program while the other half will receive normal care and a leaflet about glaucoma.
Mirtogenol and Bimatoprost on IOP in Hispanics With Open-Angle Glaucoma
GlaucomaA prospective, parallel-group, double-blind, randomized placebo-controlled clinical study will be conducted with an estimated 72 participants. The objective of this study is to determine if Mirtogenol has an additive effect on the reduction of intraocular pressure when combined with bimatoprost in the Hispanic population with primary open angle glaucoma. Baseline clinical data will be collected for each participant and they will be randomized 1:1 to a treatment group (bimatoprost 0.01% and Mirtogenol) or control group (bimatoprost 0.01% and placebo). Efficacy and safety of Mirtogenol will be measured during the 24 week study. Participants will be evaluated in five visits: screening and baseline, week 4, week 8, week 12 and week 24. The tests that will be performed include visual acuity, visual field evaluation, applanation tonometry, optical coherence tomography (OCT), and pachymetry. Side effects or adverse effects will be reported and evaluated by the ophthalmologist at each visit to access the safety of Mirtogenol. The primary efficacy endpoint of intraocular pressure (IOP) will be compared using a t-test and will have an 80% probability to detect a difference between treatments at a 0.05 significance level.