Ophthalmologists are concerned about changes in the eyes of astronauts who remain in orbit for a long time. Spaceflight-related neuroocular syndrome has been known for several years. It develops in astronauts who have been on missions for longer than one month. It is diagnosed by examining the fundus. Signs include swelling of the optic disc (where the optic nerve exits into the retina) and several other symptoms that only specialists can detect. Severe and prolonged edema and other manifestations of this syndrome threaten visual impairment. A study last year found that 70% of the crew developed neuroocular syndrome after a six-month flight.
Earlier, ophthalmologists examined cosmonauts who were in orbit for no more than six months. In a new study, American scientists are interested in the eyes of two people who participated in a research mission for one year. They were American Scott Kelly and Russian Mikhail Kornienko, CNN reports.
“After the cosmonauts began to make long, about six months, flights, we began to detect changes in the eyes of some of them. We haven’t seen anything like this since a two-week flight on the Space Shuttle, ”Brandon R. Macias, director of the Cardiovascular Health and Vision Laboratory at the Johnson Space Center in Houston, told CNN and co-author of the new study.
The scientists compared the data on the health of Kelly and Kornienko’s eyes after the flight with their indicators before departure. In both examined cosmonauts, scientists found structural changes in the eyes. One of them developed mild edema of the optic nerve, the other developed edema and progressive appearance of folds on the retina. Such folds are also potentially dangerous for vision; these changes do not always disappear completely. However, both astronauts did not complain about their eyesight.
Macias noted that longer flights can lead to more serious eye problems. In this case, the structural changes will last longer, so the risks, including irreversible damage to the retina, are increased. Flights lasting more than a year are planned for the foreseeable future, scientists plan to conduct new studies on the health of astronauts’ eyes.