VISIONARY SCIENCE:

UC San Diego is leading the charge in another branch of space medicine – eye health.

When NASA introduced eye exams into their health screenings in 2010, they noticed astronauts often needed new glasses prescrip tions after returning from space. Further tests revealed changes to their eye structure and function, including significant swelling of the optic nerve — the cable that sends visual information from the eyes to the brain.

NASA soon recruited the help of clinician–scientist Alex Huang, MD, PhD, an ophthalmologist at Shiley Eye Institute at UC San Diego Health. Huang now leads research to determine the cause
of Spaceflight-Associated Neuro- Ocular Syndrome. In 2024, Huang will be the keynote lecturer at the NASA Human Research Program Investigators’ Workshop.

Huang says the optic nerve swell ing is likely due to a buildup of fluid in the astronauts’ heads. On Earth, gravity pulls the body’s fluids toward our legs, but in the microgravity of space, this fluid is free to redistribute up toward the eyes.

“The conditions in space affect many parts of the human body, but for things like muscles and bones, we have good strategies to manage those effects,” said Huang. “For the eye, we don’t have a strategy at all.”

To address this, Huang first equipped the ISS with clinical tools for monitoring astronauts’ eyes before, during and after spaceflight to better understand the changes as they occur. 

He and his collaborators also developed a microgravity simulation on Earth in which participants spend time lying on tilted beds that position the head below the level of the feet. Eventually, they showed similar eye effects. They are now using this bed rest model to test various techniques for trapping body fluids toward the legs and away from the head.

Most recently, Huang began work ing with data science experts at UC San Diego to create artificial intelli gence tools that can predict which individuals are more or less likely to develop eye problems in space. He hopes that in the future, these tools might help NASA and other groups confirm which astronauts are best suited for longer-term missions. 

“There’s this growing interest in commercial spaceflight and long-haul space missions, but we need the new discipline of space medicine to advance along with them,” said Huang. “We can’t send people to Mars if they can’t see well enough to land back on Earth.” 

Huang was recently named one of the first endowed chairs at the Viterbi Family Vision Research Center at Shiley Eye Institute (see page 20). The new center will foster the type of collaboration and innovation that space medicine requires.

“The center was thoughtfully designed to encourage interaction and push people to talk about things they hadn’t considered doing before,” said Huang. “We really have a chance to take a swing and answer the hard questions in eye health, and the impact of that will be felt both on Earth and in space.”

Source:  https://view.publitas.com/ucsd-health-sciences/discoveries-2024/page/17