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Eye movements provide answers about the brain

Tony Pansell is investigating what eye movements and visual function can tell us about the brain. One of his discoveries is that children with cerebral palsy need reading glasses far more often than diagnosed.
“Near vision is fundamental for normal development. It is at this viewing distance all books and screens are and manual tasks are performed,” he says.

Tony Pansell. Photo: Johanna Hanno
At the time of writing his bachelor thesis, Tony Pansell was set to take over his parents’ optician business in Eksjö, but then he had a change of heart.

“It was like opening a door onto a brand new world. I realised that this was what I wanted to do, not to head home and take over the business. When I was offered a position as a doctoral student, I was delighted. I’d never considered it an option before,” says Tony Pansell, an associate professor and senior lecturer at Karolinska Institutet and an optometrist at St. Erik Eye Hospital.

Tony Pansell was the first optometrist in Sweden to complete a doctorate. In his dissertation, he describes in detail how the eyes moves in response to head movements.

Researches dizziness, double vision and blurred vision

The backbone of Tony Pansell’s research today is oculomotor function and how the senses of vision and balance are integrated and their influence on visual function.

His research is designed to find answers to questions about dizziness, double vision and blurred vision.

“The last years our research has focused on patients who have suffered traumatic brain injuries.”

These patients often experience a major change in visual function and struggle to read text, to move around without getting dizzy, going to crowded shops, watch TV etc.

“By studying eye movements and measuring visual function, we are trying to understand what happens in the brain in the event of head trauma, and whether these visual changes can be treated.”

At present, he is leading research studies on ice hockey players and downhill skiers, among others, to investigate what happens to visual function after a concussion.

“These athletes were examined by us prior to injury, which makes it easier for us to determine which visual functions have been affected following the injury,” explains Tony Pansell.

Patient-centred research

Tony Pansell also works as an optometrist at St. Erik Eye Hospital. He is a member of the neuro team that investigates eye movements and visual function in cases of different types of brain injury and brain diseases.

“Meeting patients often gives rise to new ideas for future research projects. When I come across something I haven’t seen or read about before, then I want to know more.”

From studying children with congenital brain injuries, Tony Pansell and his colleagues have discovered that children diagnosed with cerebral palsy (CP) have problems adjusting their focus (accommodation) at close range. It takes a very long time and they have difficulty maintaining that focus.

“This visual defect is underdiagnosed in children with CP. Often close-range visual acuity is not measured, but it is assumed that the children are capable of accommodation because they are children. None of the children we tested had been offered reading glasses, despite saying that their sight improved significantly when given reading glasses to try. We think it is very important to help these children quickly, because the ability to see sharply at close range is important for development.”

Fun to develop new methods

Tony Pansell is always working on becoming a better scientist.

“To become a great scientist isn’t something you are born with, it has to be learned,” he says.

According to Tony Pansell it’s about acquiring knowledge about your subject area, being able to design good experiments, establishing good partnerships, having the right questions and hypotheses to test statistically, and being able to interpret data and communicate it so that others can understand it.

A great deal of his time is currently spent on leading a research group, supervising students and postgrads, and helping colleagues with their studies. Tony Pansell finds it very stimulating to be a part of others' work. The group have also developed a number of new methods in the laboratory for stimulating the visual and the vestibular sensory system.

"This gives us a great opportunity to ask specific research questions to find answers for. It is great to be the first to break new ground and fantastic to be involved in delivering new knowledge!"

Text: Lisa Thorsén

Name: Tony Pansell
Title: Associate professor and senior lecturer at Karolinska Institutet and an optometrist at St. Erik Eye Hospital.
Research role: Research group leader, deputy head of unit, postgrad supervisor. Runs a lab together with colleagues.

Updated
13 december 2019