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Star gazing

Toronto, December 2, 2015

By Geoff Koehler

Cmdr. Chris Hadfield aboard the International Space Station
When Cmdr. Chris Hadfield was aboard the International Space Station, the Canadian astronaut recorded a video describing the eye tests astronauts do aboard the ISS so that NASA and other space agencies can learn more about the vision problems astronauts experience. Watch it on the Canadian Space Agency’s YouTube channel.

Dr. Yeni Yucel has set his sights on discoveries to prevent eye diseases around the world, but his research is not limited to Earth.

The pathologist and scientist recently visited NASA’s Johnson Space Center in Houston.

Dr. Yucel, who is also the founding director of St. Michael’s Hospital’s Human Eye Biobank, spoke with NASA scientists who are working to understand why astronauts have poorer vision after returning from space. The condition can cause near- or far-sighted vision issues and is called vision impairment and intracranial pressure, or VIIP.

“About half of male astronauts who have spent time in space experience poorer vision during and after returning from long space missions,” said. Dr. Yucel. “VIIP is seen in more males, but likely because there have been so many more male astronauts than female.”

It’s believed that weightlessness in space leads to pressure changes in the brain and spinal fluid and these pressures can cause the eyeball to change shape. Distinct physical changes to the shape of the eye are common for those with VIIP, but not every astronaut with impaired vision showed signs of the eyeball having changed shape.

A number of studies have looked for causes of VIIP and NASA is continuing this research.

Dr. Yeni Yucel
Dr. Yeni Yucel, a pathologist, scientist and the founding director of St. Michael’s Human Eye Biobank, is working with NASA to learn more about the vision problems that plague astronauts when they return from outer space. (Photo by Yuri Markarov)
Onboard the International Space Station, astronauts undergo tests to monitor vision, eye health and a test to measure pressure in the eye—which increases in space. Still, little is understood about the role of microgravity on brain pressure.

Back on Earth, Dr. Yucel’s team at St. Michael’s is able to track, map and measure how the circulatory system drains fluids from the eye and brain. NASA scıentısts and St. Michael’s researchers aim to develop collaboratıve projects to better understand and to prevent thıs condıtıon.

“The truth is out there,” said Dr. Yucel. “We’re working with NASA to find it.”

About St. Michael's Hospital

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in 27 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael's Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

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