Space goers experience brain and eye problems

We've long known that space travel can have effects on bones and muscles, but new work finds trouble with returning astronauts' brains and eyes as well.
Written by Rose Eveleth, Contributing Editor

Traveling to space is one of the coolest things anyone can do. It also comes with its fair share of risks. From potential collisions with space junk, to loss of bone density, an astronaut faces many challenges on his or her flight. Researchers might have just added yet another risk: vision problems.

In a study that looked at 27 astronauts on the International Space Station who were in space an average of 108 days, scientists found that many of them had complications involving their brain and eyes.

The study used MRI to study the eyes and brains of the astronauts. The symptoms they displayed – bulging optic nerves, changes to the pituitary, flattening of the back of the eyeballs – are mostly associated with a syndrome caused by pressure on the brain called intracranial hypertension. But, surprisingly, the astronauts did not experience some of the other symptoms common to brain pressure on land like headaches, double vision or ringing in the ears. They did experience:

  • 33% had expansion of the cerebral spinal fluid space surrounding the optic nerve
  • 22% had flattening of the year eyeball
  • 15% had bulging of the optic nerve
  • 11% had changes in the pituitary glands

Why the astronauts experience these effects is still up in the air. One theory is that in altered gravity the amount of spinal fluid around the optic nerve.

Some risks of space flight, like muscle atrophy and bone mineral loss, are already well known. So far no astronaut has been grounded due to these effects on vision. But these new health risks will have to be taken into account for future space flights.

"NASA has placed this problem high on its list of human risks, has initiated a comprehensive program to study its mechanisms and implications, and will continue to closely monitor the situation," William Tarver, chief of flight medicine at the Johnson Space Center said in the press release.

It also remains to be seen whether this will affect the burgeoning commercial spaceflight industry. While most commercial flights won’t be nearly as long as trips to the International Space Station tend to be, the passengers also won’t be as fit as NASA astronauts.

Via: Eurekalert, study in the journal Radiology

Photo of astronaut: NASA

Photo of MRI: Nevit Dilman

This post was originally published on Smartplanet.com

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