Clinical Research Directory

Study of the Benefit of Early Treatment With an Endothelin Inhibitor (Bosentan) in Patients With Sudden Blindness Due to Giant Cell Arteritis: CECIBO

Giant cell arteritis , also named Horton's disease, is the most common vasculitis in subjects over 50 years old. The incidence increases with age : from 188 to 290 cases per million inhabitants per year, with a North-South gradient. The major risk of Horton's disease is blindness, unilateral, occurring in 15 to 20% of cases, sometimes preceded by episodes of transient amaurosis. The decrease in visual acuity is often brutal, irreversible and bilateral in 25 to 50% of cases. The mechanism of this blindness is an arterial ischemia: Acute Anterior Ischemic Optic Neuropathy acute anterior ischaemic optic neuropathy (90%), acute retro-bulbar ischaemic optic neuropathy (5%), occlusion of the central artery of the retina (5%). The pathogenesis of this brutal ischemia is not fully understood. One of the hypotheses suggests that, during stimulation by an antigen of the environment, preactivated dendritic cells of the arterial wall would stimulate T lymphocytes. These will recruit cells that cause an inflammatory infiltrate polymorphic predominant at the media level. These lesions may be accompanied by destruction of the internal elastic lamina, with inconstant but pathognomonic presence of multinucleated giant cells. All arteries with internal elastic lamina can be affected by parietal inflammation, which results in stenosis and occlusion, explaining the ischemia. The visual loss is usually abrupt and very severe, leaving the patient with definitely very low or no residual visual acuity. Conventional treatment currently recommended includes systemic corticosteroid therapy at 1 mg / kg / day, preceded or not by 500 mg pulses of methylprednisolone , and associated with antiplatelet and anticoagulant therapy (LMWH). Despite the decline in visual acuity thus occurred is then always final. Certainly loss of vision has a major impact on the quality of life of patients. Apart from this lymphocytic inflammation, a process of vascular remodeling is at the origin of the vascular occlusion phenomenon. The endothelin system is a family of amino acids including 3 members: ET1, ET2 and ET3. ET1 is a potent vasoconstrictor. ET1 receptors (ETA and ETB) are expressed in the arteries of patients with giant cell arteritis . The expression of ET1 associated with proliferation of muscle cells in arteries will decrease under the effect of endothelin inhibitors. This has been shown during treatment of pulmonary hypertension. In giant cell arteritis , the endothelin system continues to be very active up to 8 days despite the introduction of systemic corticosteroids. Bosentan is a mixed endothelin receptor antagonist with affinity for both ETA and ETB receptors. This inhibitor is used in treatment of pulmonary artery hypertension, digital ulcerations of systemic sclerosis and critical peripheral arterial ischemia.

Developing Evidence-Based Cognitive Approaches to Improve Adjustment to Vision Loss

The goal of this study is to develop and pilot test a therapeutic strategy combining cognitive behavioral therapy (CBT) with mindfulness practices tailored for individuals adjusting to vision loss. The study will begin with focus groups to inform the design of the intervention. Participants will complete brief surveys on their background and experiences with vision loss prior to attending a focus group, and some may be invited to a second session to provide additional feedback before preliminary testing begins. In the pilot phase, participants will attend weekly group therapy sessions using the developed intervention and complete assessments before and after the program, including questions about vision status, demographics, and experiences with vision loss.

A Pilot Study Comparing Performance of Blind Participants on 12 Tasks, With and Without the ARIA Device

Summary The environment in which we live, play and travel is primarily built by and for people with sight. Navigating the sighted world with blindness can be exhausting, as it involves disorientation, social isolation, increased risk, frustration and inefficiency. Accessing timely information about the environment is necessary to navigate an efficient path of travel and reduce the effort involved in living with blindness. Numerous assistive technologies have been developed to improve access to information, and quality of life for people with blindness, however persistent technology limitations include affordability, unreliable internet connection, lag and limited battery life. Existing technologies can offer scene description or text-to-voice quite effectively when the user is standing still, but not quickly enough to gain benefit when on the move. Timely information is crucial at road crossings, where poor decisions can result in injury. Information lag or deficit also compounds travel fatigue due to time and energy wasted in searching, uncertainty and frustration. Blind users are often brought in to test new technologies or devices in controlled, clinical conditions, when it is too late to influence design. There is little evidence of testing these technologies in lived environments to understand the functional benefits for the blind population, partly because there is a dearth of available methods and measures to embrace the complexity of functional research. This study will test the safety, efficacy and usability of the ARIA Device in 12 varied research tasks undertaken by blind participants in clinical, social and outdoor lived environments, comparing ARIA performance with each participant's ordinary (non-ARIA) methods of undertaking the same tasks. The study uses an embedded mixed methods design with a qualitative priority, generating rich, precise data about what matters to participants and what they can do in diverse situations.