Just two weeks in orbit can damage the eyes
Monday, November 4 2013 | 00 h 00 min | News
Just 13 days in space may be enough to cause profound changes in eye structure and in the expression of some genes, according to researchers from the United States.
The study looked at how low gravity and radiation and oxidative damage affect mice after time spent in space. This study is the first to examine eye-related gene expression and cell behaviour after spaceflight.
“We found several changes in the expression of genes that help cells cope with oxidative stress in the retina, possibly caused by radiation exposure,” said Patricia Chévez-Barrios, the study’s principal investigator. “These changes were partially reversible upon return to Earth. We also saw optic nerve changes consistent with mechanical injury, but these changes did not resolve. And we saw changes in the expression of DNA damage repair genes and in apoptotic pathways, which help the body destroy cells that are irreparably damaged.”
The damage to the eyes is a problem for some astronauts back on Earth. It could also make it difficult for them to complete long missions, such as round-trip travel to Mars (12 to 16 months) or to the moons of Jupiter (two years). “We don’t know if damage caused by longer periods of oxidative stress will be more severe. Only more studies with longer exposure times may help answer this question.”