Clinical Research Directory

GORE Glaucoma Drainage Implant Clinical Study Dominican Republic

The objective of this early feasibility clinical study is to evaluate the safety and effectiveness of several different GORE Glaucoma Drainage Implant configurations in subjects with primary open-angle glaucoma that is uncontrolled by hypotensive medications or for which conventional incisional glaucoma surgery would be more likely to fail due to scarring.

Assessment of Endothelial Glycocalyx in Patients With Primary Open-angle Glaucoma

The glycocalyx is a fibrillary lining structure that covers the inner surface of blood vessels. Composed of glycoproteins and polysaccharides, it is an essential determinant of vascular endothelial physiology: it limits coagulation activation and adapts capillary perfusion. Studies have shown glycocalyx alteration in various vascular and autoimmune pathologies such as diabetes, high blood pressure, chronic renal failure, ischemic heart disease, stroke, dementia, septic shock, and several other inflammatory pathologies with a common basis in vascular insufficiency. Glaucoma is a progressive, chronic and asymptomatic optic neuropathy characterized by visual field damage and abnormalities of the optic nerve head. Two hypotheses have been proposed as a basis for this progressive damage: * the mechanical theory, which explains the papillary excavation by a compression of the optic nerve head under the effect of high intraocular pressure; and * the ischemic theory, explained by a circulatory insufficiency at the level of the blood capillaries of the retina and especially of the optic nerve head. This latter theory is related to several pathologies that have circulatory insufficiency as common underlying pathophysiology, and in which damage to the glycocalyx has been well studied. Glycocalyx damage has rarely been studied in glaucoma. Yang et al. showed that the glycocalyx, present in Schlem's canal, plays a major role in the transduction of shear stress and regulation of outflow resistance to the aqueous humor, which may constitute an interesting biomarker for glaucomatous pathologies.

Impact of Glaucoma and Visual Field Loss on Life Space

Mobility refers to a person's purposeful movement through the environment from one place to another and can be conceptualized as a continuum from bed bound (immobility) on one extreme to making excursions to distant locations on the other extreme. Primary open-angle glaucoma (POAG) is a chronic, progressive optic neuropathy that can lead to gradual loss of vision in the peripheral field and central vision. Older adults with POAG have an increased risk for motor vehicle collisions and falls. Moreover, existing studies suggest that patients with POAG exhibit more postural sway while standing as measured by a balance platform and also tend to walk more slowly than those who are normally sighted and free of ocular disease. While these disturbances likely influence mobility, there has been little research directly assessing the impact of POAG on mobility. This study will assess the impact of POAG on life space (one aspect of mobility) and will determine whether difficulties with life space are associated with difficulties experienced under conditions of dim lighting.

Retinal Photoreceptor Outer Segment Length Before and After Light Stimulation - a Pilot Study

It has been shown that reactions of human retinal photoreceptors to a light stimulus can be measured with custom-made, research prototype optical coherence tomography (OCT) systems. This can be used as a biomarker for the function of the photoreceptors. Due to the high technical demands on the system, however, the technique is currently not available for clinical purposes. In this pilot study a protocol to measure changes in retinal photoreceptor layer thickness before and after light stimulation shall be developed based on a commercial OCT system and newly developed algorithms. Other variables, such as circadian processes shall be investigated as well. After measurements in healthy volunteers, the protocol is planned to be applied in patients with primary open angle glaucoma (POAG) and age-related macular degeneration (AMD) to test for feasibility of the method in these patient groups.

MINIject Implantation Combined With Cataract Surgery in Patients With POAG and Cataract

The study will assess safety and performance of MINIject implant in patients with open-angle glaucoma uncontrolled by topical hypotensive medications in conjunction with cataract surgery.

Effects of Primary Open-angle Glaucoma on Visual-motor Coordination

Commonly used visual function assessments in glaucoma diagnosis and treatment-such as visual acuity, visual field, and contrast sensitivity-do not directly capture the impact of the disease on patients' daily abilities. While questionnaires can evaluate this impact from the patient's perspective, they are subject to individual biases and inconsistent evaluation standards. Thus, objective methods are needed to assess patients' abilities in visually guided daily activities. Grasping objects and avoiding obstacles are fundamental visually guided tasks that require effective visuomotor coordination. By attaching lightweight reflective markers to participants' limbs and using a motion capture system to track their movements in three-dimensional space, various indicators of planning, execution, and control in tasks such as object grasping and obstacle avoidance can be quantified, allowing for an objective evaluation of visuomotor coordination. However, it remains unclear how visuomotor coordination is affected in glaucoma patients at different disease stages or whether visual field damage in specific areas has distinct impacts on visuomotor coordination. This study, therefore, aims to investigate changes in visuomotor coordination among patients with primary open-angle glaucoma across disease stages and to determine the effects of visual field defects in different locations on their visuomotor abilities.