Effectiveness of a Visual Telerehabilitation Program on Visual Perception in Children, Adolescents and Young Adults With Hemianopsia Consecutive to a Brain Tumour.
试验速览
- 阶段
- 不适用
- 状态
- 尚未招募
- 入组人数
- 50
- 试验地点
- 10
- 主要终点
- Binocular Visual Field
研究概览
简要总结
Brain malignancies are the most common cause of death from cancer in the pediatric population and a major source of morbidity amongst survivors. Many children with a brain tumour often suffer from visual field defects (hemianopia) dramatically impacting their daily life with poorer social interaction, difficulties learning, playing sports and engaging with peers. Practically, they bump into people and objects and have problems in finding their way in unfamiliar places and in detecting incoming objects in their blind field. There is growing recognition of the diverse and deep impact of hemianopia on physical and mental health, quality of life, and social outcomes of the affected individuals and their family. However, despite the frequent impact of brain tumours on the visual function and functional vision, ophthalmologic evaluations are not standard of care for all brain tumour patients and there are no standardized protocols of vision loss management in the pediatric population with hemianopia. There is an unmet need of restoring perception in the blind field in individuals with hemianopia consecutive to pediatric brain tumor.
Our laboratory has developed a visual rehabilitation procedure based on the combination of adaptative audio and visual target tracking in a 3D environment in virtual reality. Participants perform audiovisual stimulation at home in a headset, with remote control from the laboratory. Preliminary on data on paediatric patients with hemianopia consecutive to a brain tumour indicate feasibility and potential effectiveness of a 6-week Re:Vision program on visual fields, visual perception and quality of life.
Our objective is to evaluate the effectiveness of Re:Vision, an 8-week visual telerehabilitation program, on visual perception in 50 individuals aged 10-40 years old with hemianopia consecutive to a pediatric brain tumor in a phase IIa/b multi-centric clinical study across Canada.
This intervention provides more equitable access to individuals, with the ability to receive rehabilitation therapy at home without supervision by a healthcare professional, meaning that Canadians living outside urban centres could take advantage of specialized therapies with remote supervision. This is the first study that could lead to a major change in the management of these patients. It could open the door for visual rehabilitation strategies to other population of visually impaired children, significantly impacting public health strategies.
详细描述
Central nervous system tumors are the second most common malignancies in childhood. A brain tumor and its treatment can affect the visual system at different levels, from the optic nerves (through compression or infiltration), to sub-cortical structures such as the superior colliculus (SC) and lateral geniculate nuclei (LGN) to optic tracts, optic radiations and visual cortices. Children with brain tumors can present visual impairments like decreased visual acuity and contrast sensitivity, loss of color vision, and visual field loss such as hemianopsias. Individuals with hemianopsia present difficulties in detecting stimuli in the defective visual field and show defective scanning and exploration. Moreover, they show a rotation and compression of the auditory space leading to imprecise localization of sound across both hemispaces. Hemianopsia patients naturally develop oculo-3D-MOTor strategies to compensate for visual field loss, but visual rehabilitation procedure must still be developed to optimize/improve visual perception in the blind field. Several studies demonstrated that individuals with hemianopsia could improve visual perception in the damaged hemifield after a stimulation procedure where auditory and visual stimuli were temporally and spatially correlated. Such repetitive audiovisual stimulation programs induce a functional and anatomical reorganization of the visual connectivity in sub-cortical and cortical structures over time mediated by perceptual learning and synaptic plasticity.
The investigators have developed an audiovisual stimulation procedure using immersive virtual reality (IVR) in head-mounted display (HMD) as a delivery platform. IVR is an emerging and very promising approach for visual and auditory rehabilitation. There are currently limited practical results whether this technology is suitable for low-vision patients to use at home and if it can be deployed on a large scale. A few case report/series studies suggested a potential effectiveness of IVR on visual perception in teenagers and young adults but more information as to the potential of use and effectiveness of this technology is necessary.
Real-time measurement of task performance and neurophysiological signals while immersed in virtual reality can bring many benefits, from monitoring experience-related factors to the development of bio/neuromarkers. In Multiple Object Tracking in 3D (3D-MOT), visual tracking and detection is directly influenced by the speed of the spheres and is tailored to the participants' performance using an adapted design to efficiently reach perceptual threshold, therefore constantly challenging the patient's perceptual abilities. Progress made by the participants can be evaluated following real-time measures such as speed of the spheres, percentage of positive hits and reaction time. These outcomes naturally increase over sessions as a learning effect (generally around 5-6 sessions in our settings) but then quickly stabilize. Further progress of performance is related to improvement in vision as a strong correlation between performance at 3D-MOT and functional vision outcomes is observed in our pilot studies.
Eye-tracking measures eye position and movement using pupil position to infer fixation, gaze durations, saccadic velocities and saccadic amplitudes which altogether reveal strategies that lead to successful detection and tracking. Eye-tracking has been extensively used during the 3D-MOT task to describe the strategies of attention allocation during visual tracking. Target/head/eye-tracking measures (positions recorded every 14 ms - 90Hz) will be used to investigate the visual strategies (head movement, saccades, fixation, smooth pursuit) developed by the participants to track the targets in 3D-MOT.
Visual field recovery and restoration from hemianopsia has been postulated to occur from both improved function of perilesional tissue and recruitment of additional cortical structures to assume the function of the permanently damaged centers. However, longitudinal studies detailing functional and structural changes in the visual system before and after treatment are lacking. EEG recordings in individuals with hemianopsia revealed some residual activity in V1. Here, brain activity in V1 will be measured before and after treatment and in comparison between control and treated group using visually evoked potential (VEP). Retinal anatomy changes will be investigated between control and treated group by measuring the ganglion cell complex (GCC) integrity and the retinal nerve fiber layer (RNFL) thickness, indicative of retinal ganglion cell atrophy using spectral domain optic coherence tomography (SD-OCT), a non-invasive imaging technique. Brain scans (Diffusion MRI, Retinotopy) will be performed using a 3T MRI at the Toronto site (Advanced MRI, Toronto Western Hospital, University Health Network) to visualize the integrity (optic radiation) and activity (primary visual cortex) of the visual system between control and treated group.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Supportive Care
- 盲法
- Single (Outcomes Assessor)
入排标准
- 年龄范围
- 10 Years 至 40 Years（Child, Adult）
- 性别
- All
- 接受健康志愿者
- 否
入选标准
- •Diagnosed hemianopsia (> 18 months).
- •History of a diagnosis of brain tumour
- •Being stable for the tumour for >18 months (either on therapy or not)
- •Male and female
- •10 - 40 years old
- •Ability to follow the visual and auditory stimuli and training instructions.
- •Online auditory test positive (-5dbHL to 60dbHL range) at 125 Hz (for research purposes only)
- •Home Wi-Fi access.
排除标准
- •< 10 years old.
- •> 40 years old.
- •Ocular disease
- •Both eyes with media opacity that impairs microperimetry testing.
- •Inability to perform during testing and training.
- •Recreational or medicinal consumption of psychoactive drugs.
- •3 consecutive VRISE (cybersickness) scores < 25 at inclusion.
- •History of vertigo or dizziness.
- •Prior vision rehabilitation interventions.
结局指标
主要结局
Binocular Visual Field
时间窗: From enrollment to the end of the study at 6 months
Difference in the number of points perceived in the Esterman binocular field test between intervention and non-intervention groups and pre/post-intervention
次要结局
- Reading Speed(From enrollment to the end of the study at 6 months)
- Contrast Sensitivity(From enrollment to the end of the study at 6 months)
- Patient-related Outcome Measures - National Eye Institute - Visual Function Questionnaire - 25(From enrollment to the end of the study at 6 months)
- Patient-related Outcome Measures - World Health Organization - Quality of Life questionnaire - BREF(From enrollment to the end of the study at 6 months)
- Fixation Stability(From enrollment to the end of the study at 6 months)
研究者
Michael Reber
Principal Investigator
University Health Network, Toronto