View clinical trials related to Vision, Low.
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The primary objective is to compare the effectiveness and adverse side-effects of the virtual bioptic telescope and virtual projection screen in a new head-mounted video-based low vision enhancement system (LVES) with a wide field of view to currently employed specifications for head-mounted video display low vision enhancement technology. Secondary objectives are to acquire qualitative information from patients to evaluate the functioning of the system, to optimize system features and operations, and to assess the value patients place on system features, functions, and operating parameters relative to those of current technology. Investigators will conduct a comparative effectiveness study to determine if the novel vision enhancing features of LVES 2 provide low vision patients with benefits superior to those provided by existing technology.
We are conducting a trial evaluating the performance of trifocal versus extended depth of focus intraocular lenses. These lenses will be implanted in otherwise healthy individuals with visual problems due to bilateral cataracts. Patients must be seeking an improvement in their visual performance with a special focus on presbyopia correction.
This study is planned to test an educational intervention promoting the use of spectacles among secondary school children. It is based on the hypothesis that educating teachers, parents and children about the importance of wearing spectacles has the potential to increase spectacle wear among children.Reasons for non-compliance towards spectacle use will be explored and educational intervention will be planned considering these reasons. Educational intervention will increase awareness about the importance of spectacles use and reduce the barriers towards spectacle use.Reducing barriers will increase compliance towards spectacles use which will ultimately prevent the avoidable visual impairment.
The aims of the Improving Communication with Formal/Informal Caregivers among Older Adults with Dual Sensory Impairment: Feasibility of Hearing Intervention in a Low Vision Rehabilitation Clinic (LVR) are: Primary aims Aim 1 To characterize prevalence of objective hearing impairment (i.e. DSI) among a clinical LVR population) in older adults (≥60 years) with English proficiency free from moderate to severe depression or cognitive decline using the Hearing Handicap Inventory for the Elderly (HHIE) assessment and an objective hearing evaluation. Aim 2 To describe the perceived burden of care on primary caregiver (identified people who assist with two or more activities of daily living. instrumental activities of daily living (ADLs/Instrumental activities of daily living (IADLs))of individuals with dual sensory impairment (DSI) among a clinical LVR population in older adults (≥60 years) with English proficiency free from moderate to severe depression or cognitive decline using the Zarit Burden Interview questionnaire and qualitative interview data analyses. Aim 3 To determine feasibility and benefit of a pilot manualized over-the-counter hearing intervention program on LVR patients to address communication among a DSI population using the Zarit Burden Interview questionnaire. 3A: Describe feasibility based on completion of pilot, drop-out rate, and semi-structured interviews 3B: Describe perceived communication improvements based on semi-structured interviews
Our study aims to validate the relevance of a virtual reality tool (VIRARE: VIrtual REality Assisted Rehabilitation) in the assessment and rehabilitation of visually impaired subjects.
The purpose of this study is to evaluate reading performance in the visual periphery by simulating central vision loss using a computer-controlled gaze-contingent display with an eye tracker. Participants will read a page of text at a comfortable rate. Several manipulations hypothesized to improve reading will be tested, such as an inverted-text "spotlight" of a single word that follows the participant's gaze.
Sellar area tumors such as pituitary adenoma, craniopharyngioma and meningioma, etc, commonly lead to visual impairment symptoms. Patients suffer from a loss of visual acuity (VA) and visual field defects (VF) due to a local compression on the optic chiasma by the tumor. In the management of these patients, it is an important goal to evaluate their visual function throughout the treatment, so as to predict the outcome of the visual function . Since the visual pathway contains a huge complex network of both structure and function, traditional simplex evaluation of VA and VF is obviously not enough. Former studies have revealed changes in the visual network and cortex structure in neurodegenerative diseases and optic neuritis, yet the functional and structural changes caused by local tumor compression and their relation to the visual cortex activity patterns needs further research. The objective of this research is to asses the visual function in patients with sellar area tumor 1 week preoperatively (baseline),72 hours postoperatively(checking point 1) and at 3 months follow up(checkpoint 2). By using multimodal evaluation including visual resting and task state fMRI, diffusion tensor imaging (DTI), etc. The investigators aim to reveal the changes in functional connectivity (FC), amplitude of low frequency fluctuation (ALFF), regional homogeneity (REHO) ,visual cortex activity patterns and tract-based spatial statistics (TBSS).
Unilateral vestibular lesions are frequent and disabling pathologies causing a set of oculomotor, postural and perceptual symptoms. These symptoms reduce over time according to a vestibular compensation. However, vestibular compensation should be considered as a set of sub-processes whose duration and recovery level differ. Indeed, after a unilateral vestibular loss, some functions remain asymmetrical as a long-term effect, and these disorders may be observed among patients with no functional complaints. Balance disorders may persist in some patients. The equilibration consists in handling real-time a considerable amount of information coming from the environment and the subject himself, allowing an adaptation of the position and movements of his body to satisfy the needs of posture, balance and orientation. This information comes mainly from the vision, the vestibule and the somesthesic system. It is pre-treated and harmonized in the brainstem, before being transmitted to the higher brain centres. Brain centers thus learn about peripheral conditions. According to these and the project of the movement, brain centers address in response orders to ophtalmological and motor effectors ensuring look, posture and balance to be provided. The eye is a cornerstone of the balancing system through the retina, an environmental sensor, and its extraocular muscles, effectors of the system. The aim of this study is to assess the effects of acute unilateral vestibular loss on visual abilities evaluated by orthoptic balance in patients who presented acute unilateral vestibular loss by surgical deafferentation (removal of vestibular schwannoma, vestibular neurotomy or surgical labyrinthectomy for Meniere's disease), during the early phase and decline of vestibular compensation. Our secondary objective is to evaluate the effect of a pre-existing anomaly of the visual abilities evaluated by orthoptic assessment on the vestibular compensation capacities. All in all, this study seems crucial to improve the management of patients with unilateral vestibular dysfunction and contribute to improving their clinical management. As a standardized management of these patients, an audio-vestibular evaluation will be performed before surgery (-1D), after acute unilateral vestibular loss at the early stage (+7D), and then after vestibular compensation (+2M) as well as an orthoptic evaluation. A good tolerance of the orthoptic evaluation is expected in this surgical context.
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.