By Michael Grace-Dacosta
A new study by a UHN research team seeks to investigate the effectiveness of a type of visual rehabilitation therapy for adults struggling with symptoms following a concussion.
The study, led by the Melissa Biscardi of UHN's KITE Research Institute, is the first to investigate the effectiveness of oculomotor rehabilitation – a type of therapy that aims to improve how the eyes move – for people who have suffered a concussion and are experiencing various visual symptoms.
"The eyes are the window to the brain," says Melissa, a PhD candidate at the Rehabilitation Sciences Institute (RSI) at the University of Toronto and a scientific trainee at KITE. "Eye movements use over 40 per cent of the brain's machinery so it's not surprising that their function could be affected by a concussion."
The average person makes more than 100,000 eye movements each day, says Melissa, who notes that these actions can be disrupted following a concussion, resulting in symptoms such as blurred vision, dizziness or headaches when reading.
Adding significantly to the importance of the study, which is commencing this month, is that it focuses on the sex-related differences between men and women who participate in oculomotor rehabilitation.
It is a timely subject following International Women's Day on March 8, a global event that celebrates the social, economic, cultural and political achievements of women and marks a call to action for accelerating women's equality.
"The trial incorporates sex and gender equity considerations, which leads to better science and understanding of the effectiveness of this treatment," says Dr. Angela Colantonio, a KITE Senior Scientist and Director of RSI who, along with fellow KITE Scientist Dr. Tatyana Mollayeva, is supervising Melissa's PhD studies.
Melissa says that a deeper understanding of how men and women respond to this form of therapy is needed to develop interventions that are optimized to women's needs.
'We cannot assume that men and women have the same needs or will have the same response'
In an effort to achieve that, she will be conducting a randomized controlled trial (RCT) of oculomotor rehabilitation. The study name, ORCA, stands for Oculomotor Rehabilitation After Concussion in Adults. Randomized controlled trials or RCAs test the effectiveness of treatments or interventions.
"There has been a feisty conversation in the scientific community regarding the effectiveness of oculomotor rehabilitation because there hasn't been a RCT," Melissa says. “The ORCA study will help move science forward.
"Even if it moves an inch, it's an inch that we need."
As part of the project, Melissa is recruiting young adults from The Hull-Ellis Concussion and Research Clinic at Toronto Rehab who have experienced visual symptoms 30 days or more following a concussion.
Over the course of the study, one group of participants will receive standard concussion care, which includes suggestions on limiting visually stimulating activities, such as time spent watching movies, playing video games and other screen-based activities.
The other group will receive oculomotor rehabilitation using a virtual reality headset and instructions on how to do eye movement exercises at home. These exercises involve tracking moving objects, focusing on targets at different distances and performing rapid shifts in gaze direction in order to retrain impaired eye movements, improve accuracy, speed and endurance.
Although it is well documented that women are more likely to suffer persistent post-concussion symptoms than men, they have long been overlooked in concussion research, says Melissa. She and her team recently conducted a systematic review and were unable to find any studies on oculomotor rehabilitation that looked at differences between men and women in response to treatment.
"The absence of research that considers the unique experience of people of different sexes has led to an incomplete understanding of concussions, oculomotor deficits and treatment effectiveness," Melissa says.
"We cannot assume that men and women have the same needs or will have the same response to an intervention."
