Researchers have developed a novel brain imaging technique that gives new hope to stroke survivors affected by sight loss.
The scientists combined data from clinical sight tests with MRI imaging to precisely map affected areas of the brain.
The technique, developed by a team at the University of Nottingham (UoN), allows identification of visual brain areas where function could potentially be improved with rehabilitation.
Each year, around 150,000 people in the UK have a stroke, a third of whom suffer from a type of sight loss called hemianopia.
PhD student Anthony Beh of UoN’s School of Psychology who led the research, said:
“A common misconception with stroke-related sight loss is that it affects vision through a particular eye.
“What is actually happening is that the eyes are seeing normally but the brain can’t process some of the information.
“This type of vision loss can be a particular problem for driving, reading or navigating a crowded space. It can also increase the risk of falls in older people.
“By exploring stroke-damaged brains with functional MRI and different kinds of visual stimulation, we found residual activity in the visual cortex, not detected by perimetry.
“This opens up possibilities for rehabilitation and offers new hope to stroke survivors.”
A visual field test called perimetry is typically used to measure residual field coverage in stroke patients. However, the technique has limitations.
Perimetry requires good attentional engagement and provides only indirect information about where in the visual pathway the key processing deficit is located.
The new study shows that perimetry can be augmented with MRI imaging, providing potential for a personalised approach to therapy.
The research was funded by Fight for Sight, a UK charity supporting research into the prevention of blindness and eye disease.
Ikram Dahman, Chief Executive Officer (Interim) at Fight for Sight, said:
“This important research gives new and much-needed hope for people experiencing sight loss due to brain injury after a stroke.
“This work could truly be transformative in people’s recovery, helping to restore independence and improve overall quality of life.
“We look forward to the important outcomes of this study.”
