WASHINGTON (AFP) - Brain and eye problems have surfaced in astronauts who spent more than a month in space, marking a potential setback to plans for longer deep space missions, a US study said Tuesday.
Shuttle missions typically lasted a couple of weeks, while ISS stints can last more than six months. A Mars mission to bring astronauts to the red planet in the coming decades could last a year and a half.
Among the astronauts who spent more than a month in space over their lifetimes, researchers found a variety of complications that appear similar to a syndrome caused by unexplained pressure on the brain.
These symptoms included excess cerebral-spinal fluid around the optic nerve in 33 percent of the astronauts studied and flattening of the back of the eyeball in 22 percent of them.
Fifteen percent had a bulging optic nerve and 11 percent showed changes to the pituitary gland — which is located between the optic nerves, secreting sex hormones and regulating the thyroid — and its connection to the brain.
Similar effects, which can lead to problems with vision, have been observed in non-space travelers who suffer from unexplained pressure buildup in the brain, a condition known as intracranial hypertension.
“Microgravity-induced intracranial hypertension represents a hypothetical risk factor and a potential limitation to long-duration space travel,” said lead author Larry Kramer, professor of diagnostic and interventional imaging at The University of Texas Medical School at Houston.