Visual Impairment – Innovation (April 2020 – No 02)
April 2020 Edition (02)
Seeing a Difference: Innovative Research
at the CRIR Concordia Vision Lab
An interview summary with Aaron P. Johnson
Associate Professor, Department of Psychology, Concordia University
Researcher, CRIR–Lethbridge-Layton-Mackay Rehabilitation Centre, MAB Site, CIUSSS West-Central Montreal
Concordia Vision Lab
Our discussion will focus on two of your projects regarding visual impairment at the CRIR Concordia Vision Lab. The first concerns a training program for improving eye movement stability and its effects on balance. The second concerns the use of eye-tracking devices to measure face perception. Let us start with the first project.
Can you describe your research on improving reading for individuals with visual impairment?
Most individuals decide to seek help when their eyesight degenerates to a point that they have trouble reading. Therefore, one of the most common targets of vision rehabilitation training is to improve reading performance. Currently the main method of improving reading is to improve the stability of the eye while reading. Often when individuals with visual impairment come to the Lethbridge-Layton-Mackay Rehabilitation Center, their eyes move erratically when reading. They find it very difficult to recognize which part of their eye still has some ability to see and to use that part in order to read.
Many rehabilitation centres, including the Lethbridge-Layton-Mackay Rehabilitation Center, offer eccentric viewing programs that train eye movement stability. The aim of these programs is to make eye movements less erratic while the eyes are focused on a single point. Individuals with normal sight are able to do this when looking directly at text. Individuals with vision loss must choose a new location in their eye that has some ability to see text.
Visual impairment is a partial loss of vision that cannot be corrected with glasses. It can happen to adults or children. Causes include stroke, diabetes and high blood pressure. It can also result from age-related macular degeneration (deterioration of the central part of the retina), cataracts, glaucoma, and eye injuries.
More than 1 million Canadians suffer from visual impairment. There are more people living with visual impairment than those with Parkinson’s and Alzheimer’s diseases combined. Estimates indicate that 1 in 10 Canadians over the age of 60 years will have some sort of visual impairment during their lifetime. By 2032, 25% of Canadians are expected to be over the age of 60, therefore the number of people with a visual impairment in Canada is also predicted to increase.
Visual impairment has a significant impact on those who experience it as well as their family and friends. It can affect one’s ability to perform daily tasks and interact with social and physical environments. Among other things, it can limit independence, mobility, education and employment achievement. It has been linked to falls, injury and cognitive impairment.
The main target of rehabilitation is to allow individuals to read better than they did before receiving the training. We can measure how many words or how easily they can read before and after rehabilitation. We can also see if there is improvement in their reading speed or in the comprehension of the text content. Our research shows statistically significant improvement in eye movement stability after training.
How is this research on improving eye movement stability linked to balance?
The CRIR New Initiatives Program award allowed us to ask the following question: “Does the training to improve the erratic nature of eye movements to make them more stable also lead to improvements in balance?” We applied our research expertise in order to address this question and work closely with CRIR researcher and vision impairment specialist Hana Boxerman and other clinicians at the Lethbridge-Layton-Mackay.
We had some initial data collected by Caitlin Murphy, a postdoctoral researcher at the CRIR Concordia Vision Lab indicating that individuals with visual impairment with more stable eye movements had better confidence in their balance skills.
In parallel to assessing individuals for eye movement stability before, during and after training, individuals are also evaluated for balance. Individuals stand on a Nintendo Wii balance board. This allowed us to measure and quantify how much an individual is moving, and in what direction and speed.
What are the findings of this research?
Preliminary results indicate that this training has transferring effects. Individuals are seeing improvement in balance and are reporting feeling more confident in performing tasks requiring balance.
Is this research innovative?
Yes. This is the first time that this has been shown so we are quite excited about it. Our research is still in its early stages and we plan to conduct more studies in this area. In addition, this research project originates from expressed interest by a clinician at Lethbridge-Layton-Mackay. Our project is based on a real clinical -research partnership. It demonstrates that as a team we can start exploring questions that otherwise each one of us alone cannot address.
What is your next step?
We would like to extend our research to a larger number of individuals, and to see if this training is more effective on certain types of visual impairment than others.
Moving on to the second project that uses eye tracking devices to measure face perception.
What is this research about?
Individuals with visual impairment often report feeling uncomfortable in social situations. In part, this is due to problems with face perception. Face perception means that they have difficulty recognizing emotions on faces as well as who the person is. Little research exists in this area.
An eye-tracking device looks like a regular pair of glasses. It allows researchers to measure eye positions and eye movement using sensors and a smart phone. The eye tracker uses two very small cameras that look into the wearer’s eyes and track their position. A third camera looks from the wearer’s viewpoint. The software on the smart phone (or computer) then overlays the wearer’s eye position onto the video of the viewpoint – allowing us to see what in the video the wearer was looking at.
How did you conduct this study?
Our study involves two groups of older adults, one with visual impairment and another with normal vision. Both groups are shown a series of images of faces taken from variable distances. We ask two questions: 1) Does the face express an emotion? 2) And if so, can you tell us what the emotion is? First, participants have to decide if there is an emotion. If they do sense an emotion, they have to correctly classify it as angry, happy, or sad.
What are the key findings of this work?
Older adults with visual impairment perform much worse than normally sighted ones. This is especially true when the size of the face gets small to the point where they are looking at it from across the room. Making faces bigger improves the ability to recognize faces and emotions.
Why is this study important from a rehabilitation research perspective?
It shows that we can quantify face perception. In addition, eye tracking allows us to see where older adults are looking and to link this to their performance. We found that older adults with visual impairment that struggle to recognize faces have erratic eye movements. They try to find a point where they still have vision in their eye to see features of the face but are unable to do so. This is similar to when individuals with visual impairment try to read.
Is there a next step?
A future direction would be to test individuals, at the Lethbridge-Layton-Mackay, who complete eye movement stability training in order to see whether there is improvement in their ability to see faces.
Overall, why is research on visual impairment important for you as a researcher?
It is important because it shows that rehabilitation is effective and we can quantify improvement. It is also significant due to my background as a vision psychologist. My research looks at how the eye and the brain function to make sense of the world around us. Psychologists have been studying vision for decades and have accumulated a wealth of knowledge. Only recently has this information started to cross over to the clinical vision rehabilitation world. I believe it is important to translate results from basic research and apply them to clinical rehabilitation. Doing so brings different insights about how to think about rehabilitation. It also allows us to bring methods, tools and techniques used in basic research in psychology to rehabilitation research. My work with eye-tracking devices is a good example of this.
How does your research differ from other work in the field?
A growing number of vision psychology researchers are interested in applying basic research to clinical practice. Currently, I am the only researcher that uses eye tracking devices in the field of rehabilitation in Montreal. Elsewhere the use of this device in visual impairment research is very limited.
Can you give me an example of the impact of your research has had on the Lethbridge-Layton-Mackay rehabilitation centre?
The Lethbridge-Layton-Mackay just bought eye tracking devices because they are seeing the benefits from our research. Clinicians have seen how useful these devices are in identifying how individuals with visual impairment perform a wide variety of tasks. They are able to gain a better understanding of the difficulties these individuals face on a daily basis.
Whom do you think your research on visual impairment will interest?
Any older adult over the age of 50 would find this interesting. Many older adults are unaware of vision rehabilitation. When their vision starts to deteriorate, they write it off as old age. What is important for individuals to know is that we can improve vision. This is possible by prescribing the correct prescription for glasses; it is also the case that individuals can seek help from vision rehabilitation specialists who can work to help them better use their remaining vision.
Interview and text: Spyridoula Xenocostas, Coordinator–Partnerships and Knowledge Mobilization, CRIR at partenariat.crir@ssss.gouv.qc.ca
