10089
0
Posted on Feb 08, 2005, 5 a.m.
By Bill Freeman
People who lose vision after stroke can have their brain rewired to see again. Called vision restoration therapy, the treatment involves identifying and stimulating regions in the visual field that are only partly damaged. A computer-based device presents the visual stimulation on a monitor to areas of residual vision.
People who lose vision after stroke can have their brain rewired to see again.
Called vision restoration therapy, the treatment involves identifying and stimulating regions in the visual field that are only partly damaged.
A computer-based device presents the visual stimulation on a monitor to areas of residual vision.
Using the device for about 30 minutes twice a day induces neuroplasticity in which nerve activity related to vision is strengthened.
"This is the first technique stroke patients can use to improve their vision," says researcher Bernhard Sabel of Otto-von-Guericke University in Magdeburg, Germany. "Patients with visual field defects can now have reasonable hope that the blindness is changeable.
Seeing benefits
Vision restoration therapy is attracting increasing attention for treating vision loss related to stroke and other brain trauma.
Boca Raton, Florida-based NovaVision received FDA clearance for its restoration system in April 2003.
Sabel and colleagues have now shown relatively long-term data on the treatment.
In their studies, fifteen people had six months of treatment and nine had 12 months of treatment.
The researchers performed visual field assessments before and after treatment and repeated the tests an average of 46 months after completion of the treatment.
After six months, stimulus detection increased from about 54% to 63%, considered significant, and the number of undetected stimuli decreased in both eyes.
Continuing for 12 months improved vision further.
Follow-up examination after no treatment for more than three years found that the benefits remained stable and vision loss didn't occur in most cases.
Patients appeared to benefit by continuing the training.
Results may vary
Neither stroke severity, amount of vision loss nor age appeared to stop people from benefiting from the treatment. As long as some vision remained, it was effective in most participants.
"We had some patients train for many years and continue to improve," says Sabel. "In rare cases, the entire [area of vision loss] disappeared."
Results do vary, however. About one-third of participants saw little or no effect, one-third had moderate improvement and one-third had dramatic improvement.
The researches say that the treatment approach can be applied to vision loss from other sources besides stroke such as trauma and tumor surgery.
The research was reported in New Orleans, Louisiana at the American Stroke Association's International Stroke Conference 2005.
Called vision restoration therapy, the treatment involves identifying and stimulating regions in the visual field that are only partly damaged.
A computer-based device presents the visual stimulation on a monitor to areas of residual vision.
Using the device for about 30 minutes twice a day induces neuroplasticity in which nerve activity related to vision is strengthened.
"This is the first technique stroke patients can use to improve their vision," says researcher Bernhard Sabel of Otto-von-Guericke University in Magdeburg, Germany. "Patients with visual field defects can now have reasonable hope that the blindness is changeable.
Seeing benefits
Vision restoration therapy is attracting increasing attention for treating vision loss related to stroke and other brain trauma.
Boca Raton, Florida-based NovaVision received FDA clearance for its restoration system in April 2003.
Sabel and colleagues have now shown relatively long-term data on the treatment.
In their studies, fifteen people had six months of treatment and nine had 12 months of treatment.
The researchers performed visual field assessments before and after treatment and repeated the tests an average of 46 months after completion of the treatment.
After six months, stimulus detection increased from about 54% to 63%, considered significant, and the number of undetected stimuli decreased in both eyes.
Continuing for 12 months improved vision further.
Follow-up examination after no treatment for more than three years found that the benefits remained stable and vision loss didn't occur in most cases.
Patients appeared to benefit by continuing the training.
Results may vary
Neither stroke severity, amount of vision loss nor age appeared to stop people from benefiting from the treatment. As long as some vision remained, it was effective in most participants.
"We had some patients train for many years and continue to improve," says Sabel. "In rare cases, the entire [area of vision loss] disappeared."
Results do vary, however. About one-third of participants saw little or no effect, one-third had moderate improvement and one-third had dramatic improvement.
The researches say that the treatment approach can be applied to vision loss from other sources besides stroke such as trauma and tumor surgery.
The research was reported in New Orleans, Louisiana at the American Stroke Association's International Stroke Conference 2005.
