Treatment For Adult Amblyopia In Sight With Magnetic Therapy

Magnetic therapy of the brain can temporarily treat poor vision in one eye in adults, also known as ‘lazy eye’ or amblyopia, new research originating in Canada indicates. This has been a significant finding, considering amblyopia was hitherto thought to be untreatable in adults.

Canadian researchers found that beaming magnetic pulses into the brain improved the sensitivity of the weaker eye temporarily. The study was prompted by reports of new research that documents the plasticity of the adult brain.

Speaking about the findings of the new research, Benjamin Thompson of Canada’s McGill University, also a member of the team involved in the study, said, “We know now that visual loss is caused by poor processing in the cortex. Treatment usually addresses the problem with the eye, not with the cortex.”

The cortex is a vital part of the brain, involved in vision, among other functions. Recent research had already shown the effectiveness of transcranial magnetic stimulation, the treatment methodology mentioned in the study, in the treatment of stroke. It is currently also being tested to quell depressiondefine in patients.

When the researchers used TMS on nine adults with amblyopia, the sensitivity of the weaker eye improved temporarily, Thompson said. Visual tests showed that the patients involved were able to perceive finer details on the aftermath of treatment.

Speaking about the findings after the test, Thompson said, “We were surprised by how well it worked. Vision in the amblyopic eye improved for at least 20 minutes after transcranial magnetic stimulation.”

For charting the way ahead, the McGill group plans to use prolonged sessions of transcranial stimulation. As Thompson put it, “We’ve only tried a single dose so far in our study. Now, we can look at the effect of repeated doses. In depression, it seems they can have an effect.”

On another level, magnetic stimulation will be used to prepare the brain for a rehabilitation program, wherein adults will be set a series of visual tasks to improve vision in amblyopic eyes.

"We will also have a parallel project, a training regime with stimuli to both eyes, higher-contrast stimuli to the amblyopic eye. We hope that repeated exposure will bring improvement," Thompson said.

Amblyopia or Lazy Eye afflicts an estimated 6 million American adults. There is some way of getting around the disease in the case of children. Early treatment of the disease often requires a child to wear a patch over the strong eye. This ensures there is more pressure on the weaker eye, thereby causing it to be more active and stronger over time.

Thompson adds, "The main message here is to show that there really is plasticity in the adult visual system. There is real momentum now to find a treatment for adult amblyopia."

The findings of the study have been published in Current Biology’s July 22 issue.