Clinical Research Directory

PAVE (Parallactic Visual-Field Enhancement) System for Treatment of Chronic Visual Field Loss Due to Stroke, Traumatic Brain Injury, or Brain Surgery

This is a research study to evaluate the effectiveness of the PAVE (Parallactic Visual-Field Enhancement) System for the treatment of chronic visual field loss due to stroke, traumatic brain injury, or brain surgery. The PAVE regimen involves the use of a virtual reality headset to deliver visual stimulation to subjects diagnosed with visual field loss. The primary objective is to demonstrate that there is an improvement in the visual field after use of the PAVE therapy over a period of eight weeks with three sessions per week. The primary outcome is an increase in visual field area as measured with Goldmann-type kinetic perimetry. The secondary outcome will be demonstration that the subjective assessment of visual function using the National Eye Institute Visual Function Questionnaire (NEI-VFQ) is better after PAVE therapy when compared to before therapy. The participants will visit the investigators office at the start of the study to establish a baseline for visual field size and visual field function. The subject will use PAVE in the office or at home three times per week for eight weeks. There will be twenty four therapy sessions in total. At four weeks the subject will visit the office and have perimetry measurements. At eight weeks the subject will visit the office and have perimetry measurements and complete the NEI-VFQ survey. Four weeks after the completion of the therapy sessions a follow up visit will take place where visual field measurement using kinetic perimetry and NEI-VFQ will be administered.

Neuromodulation Through Multisensory Stimulation for Visual Field Deficits in the Subacute Stage of Disease

Homonymous visual field defects (HVFDs) after acquired brain injuries affect daily life by impairing reading, navigation, and social activities, often impacting anxiety and depression. Spontaneous recovery is rare. Rehabilitation approaches include restorative treatments, which aim to expand the visual field through the stimulation of the so-called transition zone, and compensatory strategies, such as audio-visual training (AVT), which combines eye movement exercises with synchronized visual and auditory cues to train oculomotor scanning and overcome the visual field loss. Combining AVT with non-invasive brain stimulation, such as transcranial direct current stimulation (tDCS), may enhance recovery by promoting brain plasticity. Early evidence suggests that tDCS applied to the lesioned visual cortex during AVT can speed and stabilize improvements, potentially also restoring parts of the visual field. However, most studies on AVT have focused on chronic patients, whereas several clinical trials and international guidelines indicate that early treatment of HVFDs in the subacute phase can optimally exploit the window of maximal neural plasticity and prevent secondary degenerative processes, thereby maximizing visual recovery. In the present randomized clinical trial, we assess the efficacy of a multisensory audio-visual training (AVT) combined with tDCS in patients with subacute HVFDs after stroke (\<3 months post-lesion). Participants are randomly assigned to two groups: AVT combined with real anodal tDCS applied to the lesioned occipital cortex (Group 1), or AVT combined with sham tDCS (Group 2). The AVT requires participants to orient their gaze toward spatio-temporally congruent, cross-modal audio-visual stimuli (starting from a central fixation) and press a button as quickly as possible upon detecting the visual target. All stimuli are presented on 2mx2m panel embedded with 40 LEDs and loudspeakers (Diana, Casati, Melzi, Marzoli, et al., 2024). The training will be administered for 90 minutes daily over 10 consecutive days. All participants underwent a neuro-ophthalmological evaluation and neuropsychological assessment of visuospatial functions before the beginning of the training (t0), at the end of the training (t1), at 2 months (t2) and after 1 year (t3).

Visual Rehabilitation After Occipital Stroke

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.

Ongoing Effect of Expansion Prisms Following the Discontinuation of Use on Visual Field Enlargement and Retrograde Ganglion Cell Degeneration in Homonymous Hemianopia Patients

The goal of this observational study is to learn about the long-term effects of Pelli prism in Hemianopia patients who take Prisms for awareness of the area they cannot see. The main question it aims to answer is: Does the field enlargement observed with the prism continues after the prism is removed? Participants already using Peli prisms as part of their regular medical care for Hemianopia, in the upcoming routine controls their field of vision enlargements will be examined.