The traditional view has been that the brain is hardwired in early childhood, therefore one could not expect significant recovery of function in an adult’s injured brain. Recent findings show that in fact the brain has remarkable plasticity that is retained throughout an adult’s lifetime, and hence specific therapies for both motor and visual impairments have been developed leading to significant recovery. The process that the brain goes through to regain lost functions, for example lost vision is called neuroplasticity. When a brain is damaged so is the network of neurons that process vision. Some networks in the brain however are duplicated and the systematic stimulation of the damaged area with light stimuli at a specific location enables the activation and usage of alternative routes to process the visual information. The brain in essence develops a bypass mechanism. Repetitive stimulation has proven effective not only in vision but also in the recovery of other functions such as movements of lower limbs after stroke.
VRT is designed to strengthen the visual information processing of residual neuronal structures that have survived following acute lesions of the nervous system resulting from trauma, stroke, inflammation, or elective surgery for removal of brain tumors. By repeated activation through the course of the therapy, VRT is designed to improve the neuronal efficacy of such residual cells, i.e., patients use the program to train and improve their impaired visual functions, and thus regain useful vision in the area of the visual field deficit.
While the patient focuses on a central fixation point on a computer screen, light stimuli are repetitively presented in the transition zones between the intact and damaged visual field. These areas have the highest potential to improve. Light stimuli parameters (i.e., size and brightness) are determined to address each patient’s unique needs. Patients are made to respond to the repetitive stimulation, such that visual processing in the areas of impaired vision is repetitively activated over the course of the therapy leading to recovery of visual function.
VRT has multiple phases, including diagnostics, stimulation and evaluation of visual performance. In the diagnostic phase, it is essential to establish the precise limits and boundaries of the lost vision. This is done initially using High-Resolution Perimetry (HRP) when small white light dots are briefly presented on a grid (central ±20 x ±15 degrees) in random locations. Detection of a dot requires patient response. The task is repeated 3 times and the results are averaged. A map of visual sensitivity is then produced based on the frequency of detection at each point. In addition, the reaction time of the patient is recorded.
Following the initial diagnostic phase, the patient undergoes repeated stimulation of a the areas of the impaired visual field that show residual vision and are therefore most likely to improve. Intense, frequently repeated light stimulation has proven to strengthen and restore visual functions in the targeted areas of the visual field.
While patients are performing the stimulation therapy at home, performance quality parameters are controlled: a central fixation point changes intermittently color or shape and the patient is required to respond after each change. A lack of response after a fixation change is a measure of fixation accuracy whereas a button press in the absence of a target presentation is considered as a false alarm response.
The final stage of VRT involves determination of visual fields, using High-Resolution Perimetry (HRP), when again detection of very small white dots at multiple locations is measured repeatedly, and the responses after three consecutive runs are averaged to obtain a map of visual sensitivity. Visual fields are then compared pre and post VRT to assess the improvements gained.
VRT is supported by 15 years of research with clinical and papers studies published in more than 20 leading journals, of which some of the key findings can be summarized as:
- Approximately 70% of patients experience positive outcome reflected by an increase in their visual field and studies have indicated an average increase of 4.9 degrees (Mueller I, et al., 2007; Romano JG, et al., 2008).
- Elapsed time since injury does not seem to impact VRT therapies success. Therefore, a large historical backlog of patients can potentially be treated (Romano JG, et al., 2008).
- Improvements are permanent and do not appear to be age or gender dependent.
The average approximate five-degree improvement in central vision from VRT can make a significant difference in patients’ daily lives ((Gall C, et al,. 2008) and patients experienced a functional improvement such as improvements in their vision that impact their ability to read, walk, watch TV, and socialize comfortably.
- Visual field enlargement after computer training in brain-damaged patients with homonymous deficits: an open pilot trial
Authors: Kasten E., Sabel BA.
Publication: Restorative Neurology and Neuroscience. 1995; 8:113-127
- Computer-based training for the treatment of partial blindness
Authors: Kasten E., Wuest S., Behrens-Baumann W., Sabel B.A.
Publication: Nature Medicine 1998; 4: 1083-1087
- Vision restoration therapy (VRT) efficacy as assessed by comparative perimetric analysis and subjective questionnaires
Authors: Sabel B.A., Kenkel S., Kasten E.
Publication: Restorative Neurology and Neuroscience 2004; 22:399-420
- Does VRT Change Absolute Homonymous Visual Field Defects? A Fundus-Controlled Study
Authors: Reinhard J., Schreiber A., Schiefer U., Kasten E., Sabel B.A., Kenkel S., Vonthein R., Trauzettel-Klosinski S.
Publication: British Journal of Ophthalmology, 2005; 89:30-35
- Effect of visual restitution training on absolute homonymous scotomas
Authors: Schreiber A., Vonthein R., Reinhard J., Trauzettel-Klosinski S., Connert C., Schiefer U.
Publication: Neurology 2006; 67:143-145
- Visual field changes after a rehabilitation intervention: Vision restoration therapy
Authors: Romano J.G., Schulz P., Kenkel S., Todd D.P.
Publication: Journal of the Neurological Sciences 2008; 273:70-74
- Recovery of visual field defects: A large clinical observational study using vision restoration therapy
Authors: Mueller I., Mast H., Sabel B.A.
Publication: Restorative Neurology and Neuroscience. 2007; 25:563-572
- Effects of long-term use of Vision Restoration Therapy (VRT) and stability of visual field improvements > 3 years
Authors: Gall C., Müller I., Kaufmann C., Sabel B.A.
Publication: Poster presented at Annual Meeting of the North American Neuro-Ophthalmology Society 2006
- Stability of Visual Field Enlargements Following Computer-Based Restitution Training – Results of a Follow-up
Authors: Kasten E., Müller-Oehring E., Sabel B.A.
Publication: Journal of Clinical and Experimental Neuropsychology. 2001; 23:297-305
- Multifactorial predictors and outcome variables of vision restoration training in patients with post-geniculate visual field loss
Authors: Poggel D.A., Mueller I., Kasten E., Sabel BA.
Publication: Restorative Neurology and Neuroscience 2008; 26:321-339
- Vision Restoration Therapy after brain damage: subjective improvements of activities of daily life and their relationship to visual field enlargements
Authors: Mueller I., Poggel D.A., Kenkel S., Kasten E., Sabel B.A.
Publication: Visual Impairment Research 2003; 5: 157-178
- Vision and health-related quality of life before and after vision restoration training in cerebrally damaged patients
Authors: Gall C., Mueller I., Gudlin J., Lindig A., Schlueter D., Jobke S., Franke G., Sabel B.A.
Publication: Restorative Neurology and Neuroscience 2008; 26:341-353
- The topography of training-induced visual field recovery: Perimetric maps and subjective representations
Authors: Poggel D.A., Mueller-Oehring E., Kasten E., Bunzenthal U., Sabel BA.
Publication: Visual Cognition 2008; 16:1059
- Visual field recovery after vision restoration therapy (VRT) is independent of eye movements: An eye tracker study
Authors: Kasten E., Bunzenthal U., Sabel B.A.
Publication: Behavioural Brain Research 2006; 175:18-26
- Attentional cueing improves vision restoration therapy in patients with visual field defects
Authors: Poggel D.A., Kasten E., Sabel B.A.
Publication: Neurology, 2004; 63:2069-2076
- Vision restoration through extrastriate stimulation in patients with visual field defects – a double-blind and randomized experimental study
Authors: Jobke S., Kasten E., Sabel B.A.
Publication: Neurorehabilitation and Neural Repair 2009; 23:246-255
- Brain Activity Associated With Stimulation Therapy Of The Visual Border Zone In Hemianopic Stroke Patients
Authors: Marshall R.S., Ferrera JJ., Barnes A., Zang X., O’Brien K.A., Chmayssani M., Hirsch J., Lazar, RM.
Publication: Neurorehabilitation and Neural Repair. 2008; 22:136-144
- Functional brain imaging, clinical and neurophysiological outcome of visual rehabilitation in a chronic stroke patient
Authors: Julkunen L., Tenovuo O., Vorobyev V., Hiltunen J., Teräs M., Jääskeläinen S., Hämäläinen H.
Publication: Restorative Neurology and Neuroscience 2006; 24:123-132
- Retinal Microperimetry as a Means to Assess Visual Field Expansion in Visual Restoration Therapy
Authors: Chmayssani M., Minzer B., Saxena N., Arogyasami R., Lazar R., Greenstein V., Marshall R.
Publication: Poster presented at the annual meeting of the American Academy of Neurology,AAN 2008
- Stability of the Blind Spot as a Measure of Fixation Stability in Visual Restoration Therapy
Authors: Marshall R.S., Schulz P., Kenkel S., Romano J.
Publication: Poster presented at the annual meeting of the American Academy of Neurology 2008
- Visual function in anterior ischemic optic neuropathy: Effect of Vision Restoration Therapy – A pilot study
Authors: Jung CS., Bruce B., Newman NJ., Biousse V.
Publication: Journal of the Neurological Sciences 2008; 268:145-149
- Computer based vision restoration therapy in glaucoma patients: A small open pilot study
Authors: Gulin J., Mueller I., Thanos S., Sabel BA.
Publication: Restorative Neurology and Neuroscience 2008; 26:403-412
- Combining Visual Rehabilitative Training and Noninvasive Brain Stimulation to Enhance Visual Function in Patients With Hemianopia: A Comparative Case Study
Authors: Ela B. Plow, PhD, PT, Souzana N. Obretenova, BA, Mark A. Halko, PhD, Sigrid Kenkel, Dipl Psych, Mary Lou Jackson, MD, Alvaro Pascual-Leone, MD, PhD, Lotfi B. Merabet, OD, PhD
Publication: American Academy of Physical Medicine and Rehabilitation
- Comparison of Visual Field Training for Hemianopia With Active Versus Sham Transcranial Direct Cortical Stimulation
Authors: Ela B. Plow, PhD1,2, Souzana N. Obretenova1, Felipe Fregni, MD, PhD1, Alvaro Pascual-Leone, MD, PhD1,3, and Lotfi B. Merabet, OD, PhD, MPH1
Publication: Neurorehabilitation and Neural Repair