View clinical trials related to Visual Impairment.
Filter by:The National Eye Institute estimated about 3 million people over age 40 in the US had low vision in 2010 and projects an increase to nearly 5 million in 2030 and 9 million in 2050. Current assistive technologies are a patchwork of mostly low-technology aids with limited capabilities that are often difficult to use, and are not widely adopted. This shortfall in capabilities of assistive technology often stems from lack of a user-centered design approach and is a critical barrier to improve the everyday activities of life (EDAL) and the quality of life (QOL) for individuals with low vision. An intuitive head mounted display (HMD) system on enhancing orientation and mobility (O&M) and crosswalk navigation, could improve independence, potentially decrease falls, and improve EDAL and QOL. The central hypothesis is that an electronic navigation system incorporating computer vision will enhance O&M for individuals with low vision. The goal is to develop and validate a smartHMD by incorporating advanced computer vision algorithms and flexible user interfaces that can be precisely tailored to an individual's O&M need. This project will address the specific question of mobility while the subject crosses a street at a signaled crosswalk. This is a dangerous and difficult task for visually impaired patients and a significant barrier to independent mobility.
In industrialized nations diabetic retinopathy(DR) is the most frequent microvascular complication of type 2 diabetes mellitus and the leading cause of visual impairment and blindness in the working-age population. The well-accepted strategy for prevention and treatment of diabetic eye complications focused on confirmed diabetic retinopathy, diabetic macular edema, cataract, etc, and there was no definitive therapy for preclinical central visual acuity (CVA) impairment, mainly because of its unknown pathogenesis. In our previous population-based study, the prevalence rate of early CVA impairment was as high as 9.1%, and that obviously limits the effects of diabetic eye diseases prevention and early-stage treatment strategy. Of note, the choriocapillaris is the only route for metabolic exchange in the retina within the foveal avascular zone, it was speculated that early CVA impairment is related to diabetic choroidopathy (DC). Recent research shows that the decreased macular choriocapillaris vessel density (MCVD) in diabetic eye ,which indicating early ischemia, is already present before diabetic macular edema can be observed; we have observed subfoveal choroidal thickness (SFCT) decreased significantly in the early CVA impairment patients. However, up til now, there was no epidemiology report on early CVA impairment in Chinese diabetes population. In the present study, we plan to conduct a 10-year perspective cohort observation of 2217 Chinese type 2 diabetic residents without diabetic retinopathy, diabetic macular edema, cataract and other vision impairing diseases, trying to find out related physical and biochemical risk factors. The results will facilitate discriminating high risk groups of early CVA impairment in diabetic patients. In the same time, a quantitative relationship between SFCT change, MCVD change and CVA change will be established. This study will demonstrate the role of DC in the occurrence of preclinical CVA impairment, and provide important theoretic evidence of blocking agents which target on DC.
The aim of this study is to measure visual acuity, contrast sensitivity and visual field by SAP-method using a novel device Ocusweep compared to currently widely used methods. Addition to that, the aim is to validate a novel perimetry method (Visual Search Test, VST) which is based on reaction times in visual decision- making task, where the subject is allowed to move eyes and where the fixation is verified by the subject himself in contrast to standard automatic perimetry (SAP) where prolonged stationary fixation and external fixation monitoring apparatus is required. Reaction-time based visual field device Ocusweep is compared to generally used SAP methods. Those tests will be done for healthy volunteers and for persons with diagnosed eye or brain disease. Ocusweep OcuRT vision based choice reaction time test is validated for test repeatability and compared to Trail Making Test (TMT), Useful Field of View (UFOV) and Vienna Test System (VTS) reaction time tests. To evaluate the ability to detect unreliable results, OcuRT test is also done under cognitive load and with instructions to cheat the test.