Medical Device Daily Associate Managing Editor

In most cases, it's said that staring at a computer or television screen is bad for one's vision - ask any mother. However, in a special new treatment developed by German doctors, staring at a computer screen is encouraged and may actually help to restore vision to stroke victims or sufferers of traumatic head injuries.

The new breakthrough, called Vision Restoration Therapy (VRT), was developed by NovaVision (Boca Raton, Florida/Magdeburg, Germany) and is designed to work as a sort of physical therapy for the brain. VRT is based on the concept of neuroplasticity, which is the ability of partially damaged neurons in the brain to compensate for injury, in this case to vision, and adjust their activity in response to stimulation from the environment.

The therapy was granted a 510(k) clearance by the FDA in April 2003, and is intended for the diagnosis and improvement of visual functions in patients with impaired vision that may result from trauma, stroke, inflammation, surgical removal of brain tumors or brain surgery, and may also be used in patients with amblyopia.

The computer-based VRT employs visual stimulation to restore large portions of vision lost as a result of brain trauma or damage to the optic nerve. After a stroke or traumatic head injury, a zone of residual vision exists between damaged and undamaged regions within vision-processing areas. Within this zone, there are areas that can be improved using precise patterns of visual stimulation. This stimulation of undamaged neurons can increase their functionality.

"The whole field of neuroplasticity is relatively young," said Navroze Mehta, president and chief executive officer of NovaVision. "It was initially thought the brain was hardwired, and clearly now there's been a lot of bodies of work showing that the brain is indeed very plastic," he told Medical Device Daily. He said it is believed, as with other modes of physical therapy, "that new neuronal pathways are formed" when a patient is subjected to regulated visual therapy.

The therapy was co-developed by Bernhard Sabel, a psychologist specializing in patients who have become partially blind following strokes or head injuries, at the University of Magdeburg Medical School (Magdeburg, Germany). Sabel's treatment, which he developed with colleagues Erich Kasten, Stefan Wust and Wolfgang Behrens-Baumann, has been demonstrated to be effective for those patients whose strokes or injuries have left them with a narrowed field of vision. For these individuals, the normal view of the world is replaced by a narrow field of vision that divides itself into three distinct areas. In areas where cells have escaped harm, vision remains normal. Where massive cell death has occurred in either the optic nerve or vision-processing areas there is simply insufficient sensory information for the brain to construct an image.

Between these two areas lies the aforementioned "transition zone." Here, a sufficient number of cells have survived to provide some signals and some signal-processing ability, but the resulting view is too distorted to provide useful visual information.

Mehta said that the VRT could one day be added to the three well-established modalities - or as he termed them, "pillars of therapy" - for the treatment of a stroke victim. These pillars include speech, physical and occupational therapy. He said that about 15% of all stroke patients experience visual impairments of some form, and after a six-month period of what is called "spontaneous recovery" nothing further of a restorative nature is offered as in the other therapy modalities to these patients. "Now there is, for the first time, a restorative therapy available to them."

Sabel's ability to explore the brain's recuperative powers - and later develop a vision-reclamation technique - was made possible by the personal computer. The PC's first use is to locate survivor cells and determine if there are enough of them to retrain. In this examination, patients focus on a fixation point, which appears as a star on a computer monitor. They are instructed to watch for the appearance of flashing white dots and respond by hitting a letter on the computer's keyboard.

To help keep the subjects' eyes from wandering, researchers also tell them to hit the key when the star changes colors. Analyzing the hit count determines if there are sufficient "islands of residual vision" that can be expanded with follow-up treatment. According to the company, usually 10% or more of cell survival is sufficient for recovery.

The treatment is similar to the evaluation and can be done at home. As in the test, the patient sits in front of the computer and strikes a key when he sees dots. The company believes this repetitive activity strengthens the connections among the surviving neurons.

The initial phase of therapy typically lasts for six months. In this phase, a patient will perform one hour of daily therapy prescribed in time intervals based upon the individual's needs and abilities. NovaVision evaluates patients' results and the individual therapy is updated based on progress. Later, the patient returns to a partner clinic to receive an updated program for the next four weeks of therapy, along with a comprehensive summary of an individual's progress.

According to the company, clinical studies have shown that more than 65% of patients have exhibited improvement in their vision after completing the initial six months of therapy.

Interestingly, Mehta said that it is believed that VRT can be administered in patients that suffered a stroke or brain injury many years ago and still prove effective. "Most people would have initially thought that you would have to do [the therapy] within a year or six months of the lesion occurring, and that has been proven in scientific studies that we have done to be not true."

He noted that they've gone back as far as treating a World War II veteran "and shown some fairly remarkable results." He said that it is believed that plasticity does not decrease because of age of lesion. "That gives hope to a lot of patients who are out there who have never had vision therapy available to them."

The company raised $6 million in a Series A round financing that closed on Aug. 28, 2003. Noro-Moseley Partners funded the round. The company said that funding would be used to launch NovaVisions's product in the U.S. and European marketplaces. Mehta said the therapy will initially be marketed to neuro ophthalmologists and neurologists.

Published: February 11, 2004