View clinical trials related to Vision Disorders.
Filter by:This study is driven by the hypothesis that navigation for users of retinal prosthetics can be greatly improved by incorporating Spatial Localization and Mapping (SLAM) and object recognition technology conveying environmental information via a retinal prosthesis and auditory feedback. The investigators will study how effectively the SLAM technology enables the visual prosthesis system to construct a map of the user's environment and locate the user within that map. The technology will be tested both with normally sighted individuals donning a virtual reality headset and with retinal prosthesis users (Argus II).
Patients may experience metamorphopsia, or image distortion, after having vitrectomy to repair their rhegmatogenous retinal detachments (RRDs) especially those with a detached macula. Retinal displacement, as measured on autofluorescence photography, likely contributes to this distortion. There is no study in the scientific literature comparing the rate of retinal displacement and its association with visual function, including metamorphopsia, in patients undergoing different procedures for RRD repair. Based on the recently published PIVOT trial, patients who underwent Pneumatic Retinopexy (PnR) had less vertical distortion at 12 months than patients who had Pars Plana Vitrectomy (PPV). It is hypothesized that PnR will cause less retinal displacement than PPV for patients with macula-off primary retinal detachment.
Patients may experience metamorphopsia, or image distortion, after having vitrectomy to repair their rhegmatogenous retinal detachments especially those with a detached macula. Retinal displacement, as measured on autofluorescence photography, likely contributes to this distortion. It is thought that the retina slips inferiorly due to the residual subretinal fluid shifting as the patient transitions from the supine position intraoperatively to the sitting up position in the immediate postoperative period. By having the patient immediate position facedown or according to the retinal break, the risk of slippage is theoretically decreased.
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 purpose of this protocol is to determine if the Welch-Allyn Spot Vision Screener (SPOT) is effective at detecting various risk factors for poor vision in developmentally delayed children. These children have a higher percentage of vision disorders than the average population. The SPOT screen itself takes about six seconds to complete. It produces a photograph of the eye and a print out with amount of hyperopia, myopia, astigmatism and pupil size. The subject will have three SPOT screens around the time of their standard of care eye exam. The data obtained from the three SPOT screens will be compared among themselves for accuracy and to the findings of the clinical eye exam.
Blindness and visual impairment severely impact the visual health and life quality of people, particularly the 2.566 million senior citizens aged at 65 and above in Shanghai. The main reason is uncorrected refractive error, of which, 62.1% can be solved through refractive correction. For this reason, the uncorrected refractive errors of 154,000 senior citizens in Shanghai can be taken as a priority among the public health issues to prevent blindness. Now, with the aim to reduce the prevalence rate of blindness and visual impairment, it is planned to establish a public health service mechanism in terms of refractive error screening and correction for the elderly by relying on Shanghai's three-level (city-district-community) eye diseases prevention network, using proper refractive correction technology, and moving related services forward to communities in order to screen, identity, and correct blindness and visual impairment caused by refractive errors as early as possible.
High myopia retinopathy has become the first cause of irreversible blindness and severe visual impairment in Chinese adults, in order to avoid the blind and visual impairment caused by high myopia retinopathy, it is very necessary to research the mechanism of early visual impairment to prevent and control damages. Our recent research found that the decreasing of macular retina vascular density and subfoveal choroidal thickness, the increasing of Beta Zone area in optic atrophy and the rising of glycosylated hemoglobin in high myopia patients were significantly related to visual impairment, which suggested that the source of visual impairment was the abnormal structure changes surrounding optic and fovea, but so far there is no related study. We will conduct a 5 years prospective cohort study in the population of 2420 high myopia and controls which have established in college student population, working population and aged more than 50 years old population, using the latest OCT-A and SS-OCT to measure macular retina vascular density, subfoveal choroidal thickness, Beta Zone area in optic atrophy, combined with the semiparametric mixed effects model, we will analysis the prediction index between fundus structure parameters, blood biochemical index and individual characteristics prediction to explore the public health management mode of early prevention and treatment during high myopia population.
The aim of this study is to obtain an early biomarker of amyotrophic lateral sclerosis and Friedreich's Ataxia which allows to diagnose the disease in an initial stage and to follow up the patient with optic coherence tomography, a fast, non-invasive and comfortable method
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.