Active clinical trials for "Hemianopsia"

This clinical trial will evaluate the efficacy of two types of high-power prism glasses that provide field of view expansion for patients with homonymous hemianopia (the complete loss of half the field of vision on the same side in both eyes).

This research aims to understand the efficacy of a visual training task to improve visual loss after stroke, also known as hemianopia. The investigators aim to understand whether training can improve vision and which areas or pathways in the brain are responsible for this improvement.

Patients with brain injury secondary to stroke, surgery, or trauma frequently suffer from homonymous hemianopia, defined as vision loss in one hemifield secondary to retro- chiasmal lesion. Classic and effective saccadic compensatory training therapies are current aim to reorganize the control of visual information processing and eye movements or, in other words, to induce or improve oculomotor adaptation to visual field loss. Patients learn to intentionally shift their eyes and, thus, their visual field border, into the area corresponding to their blind visual field. This shift brings the visual information from the blind hemifield into the seeing hemifield for further processing. Patients learn, therefore, to efficiently use their eyes "to keep the 'blind side' in sight". Biofeedback training (BT) is the latest and newest technique for oculomotor control training in cases with low vision when using available modules in the new microperimetry instruments. Studies in the literature highlighted positive benefits from using BT in a variety of central vision loss, nystagmus cases, and others.The purpose of this study is to assess systematically the impact of BT in a series of cases with hemianopia and formulate guidelines for further use of this intervention in vision rehabilitation of hemianopia cases in general.

This is a randomized, pilot interventional study in participants with visual field deficit (VFD) caused by cortical lesion. Damage to the primary visual cortex (V1) causes a contra-lesional, homonymous loss of conscious vision termed hemianopsia, the loss of one half of the visual field. The goal of this project is to elaborate and refine a rehabilitation protocol for VFD participants. It is hypothesized that visual restoration training using moving stimuli coupled with noninvasive current stimulation on the visual cortex will promote and speed up recovery of visual abilities within the blind field in VFD participants. Moreover, it is expected that visual recovery positively correlates with reduction of the blind field, as measured with traditional visual perimetry: the Humphrey visual field test. Finally, although results will vary among participants depending on the extension and severity of the cortical lesion, it is expected that a bigger increase in neural response to moving stimuli in the blind visual field in cortical motion area, for those participants who will show the largest behavioral improvement after training. The overarching goals for the study are as follows: Group 1 will test the basic effects of transcranial random noise stimulation (tRNS) coupled with visual training in stroke cohorts, including (i) both chronic and subacute VFD stroke participant, and (ii) longitudinal testing up to 6 months post-treatment. Group 2 will examine the effects of tRNS alone, without visual training, also including chronic and subacute VFD stroke participants and longitudinal testing.

This research aims to examine changes in plastic potential of the visual system with time from stroke affecting primary visual cortex. We will measure structural and mechanistic aspects of progressive degeneration along the early visual pathways, correlating them with changes in visual performance, and in responsiveness to visual restoration training. This project will advance both scientific knowledge, as well as technical capability and clinical practices for restoring vision and quality of life for people suffering from cortical blindness.

The current proposal is to generate "proof of concept" evidence that hemianopia can be successfully rehabilitated in humans when this multisensory rehabilitation paradigm is used.

This study evaluates the efficacy of visual perceptual learning for the treatment of visual field defect caused by brain disease. Half of participants will receive visual perceptual training using the VIVID Brain. The other half will not receive any training because there is no standard treatment for visual field defect caused by brain disease.

This project is intended to collect data using standard clinical tests and psychophysics to quantify the effect of visual cortical damage on the structure of the residual visual system, visual perception, spatial awareness, and brain function. The investigators will also assess the effect of intensive visual retraining on the residual visual system, processing of visual information and the use of such information in real-world situations following damage. This research is intended to improve our understanding of the consequences of permanent visual system damage in humans, of methods that can be used to reverse visual loss, and of brain mechanisms by which visual recovery is achieved.

This study investigates a new technology to assess the structure and function inside the eye. Retinal imaging of subjects with inner and outer retinal defects to detect areas of abnormal structure and function compared to other visual function tests.

This study seeks to determine the extent of the visual capabilities that can be restored in hemianopic stroke patients by a multisensory training technique and evaluate changes in the brain that the training induces. The effectiveness of the technique will be evaluated in two interventional contexts: patients whose blindness is long-standing and stable, and another in which intervention is as soon as possible after the stroke.