April 2, 2009

New Treatment Helps Stroke Victims Regain Vision

When Millie Sauer tried to read a book while recovering from a surgery, she had trouble seeing the page for the first time.   

Sauer, 69, had suffered from a stroke hours or even days earlier that had damaged her vision.  Unfortunately, she was far beyond the point for effective treatment.

"I was told I would have to live with my situation," Sauer told Reuters News.

But a new computer-based treatment has helped Sauer regain some of her vision, and gives her hope for more improvements.

"We were very surprised when we saw the results from our first patients," said Krystel Huxlin of the University of Rochester Eye Institute, who tested seven stroke patients with the new computer-based treatment.

"This is a type of brain damage that clinicians and scientists have long believed you simply can't recover from. It's devastating, and patients are usually sent home to somehow deal with it the best they can."

Huxlin and colleagues, whose report appears in the Journal of Neuroscience, said their new treatment relies on a phenomenon called blindsight, where a person with vision problems senses something they cannot physically see.

"It is interesting that if you forced them to guess ... they can sometimes guess correctly," Huxlin said.

The new treatment requires patients to focus the damaged area of vision at a computer screen.  Dots move across the screen in formation, and the patient must decide which direction they are moving.

"The patients can't see the dots, but they're aware that there is something happening that they can't quite see. They might say, 'I know that there's something there, but I can't make any sense of it,'" said Huxlin.

The patients eventually learn to use their "blindsight," even though they still cannot fully see.

Sauer and other patients can now shop, drive, and live fairly normal lives.

"I think I have been able to live a pretty fulfilling life," Sauer said.

To Huxlin, the improvements in vision have been surprisingly substantial.

According to Huxlin, the success rate for the treatment has grown from roughly 50 percent, to 80 or 90 percent.

A stroke can damage the areas of the brain that interpret images being sent to it from the eye.  So although the eye may be functioning correctly, the brain cannot correctly process the information.

"A lot of neurologists and clinical practitioners are not aware that it is possible to regain vision after stroke," Huxlin said.

Huxlin developed the treatment after seeing stroke patients come out of partial paralysis due to physical therapy.

She saw no reason why the same could not be done with vision, and her new treatment is proving that it can.


On The Net:

University of Rochester Eye Institute

Journal of Neuroscience