Recently released research has managed to explain why astronauts have been suffering from a visual impairment problem, especially after longer missions.
The research was presented on Monday during the Radiological Society of North America or RNSA’ annual meeting.
The study was carried out by a team of researchers from the Miller School of Medicine of the University of Miami and was led by Noam Alperin.
Research studied the effect and cause of appearance of the VIIP or the impairment intracranial pressure syndrome.
Following long-term space missions, astronauts have been noticed to be suffering from a visual impairment problem. The problem was noticed to be caused by changes which are not always temporal.
But researchers were unsure as to what were the exact causes of these changes, which were reported in nearly two-thirds of the astronauts returning from ISS missions.
The values were registered amongst ISS or International Space Station astronauts which spent longer periods of time out in Space.
As by 2010 the visual impairment problem has become more apparent and somewhat more permanent, NASA scientists decided to study the VIIP.
The United States NASA Space Agency flight surgeons had already revealed that astronauts had a blurry vision, but further tests have managed to reveal the cause.
It was determined that the astronaut’s visual problems were determined by the liquid volume changes registered at the spinal cord and brain levels.
Various other structural changes were also analyzed and registered, as they were determined to be reversible.
However, the new study also revealed that the optic nerves inflammation of the eyeballs had a different cause than it was previously believed.
As these are the factors which caused the visual impairment problem, previous research presented the vascular liquid shift as being the cause.
Scientists considered that the problem may have been related to the vascular fluid shift towards the upper body determined by the space microgravity.
Still, Dr. Alperin’s study investigated another possibility and discovered the actual cause in the form of the CSF.
The CSF or cerebrospinal fluid helps by both cushioning the spinal cord and the brain and by removing waste materials.
As the CSF adapts and should help accommodate hydrostatic pressure changes, the space microgravity seems to pose new problems.
Research established that while the fluid can easily adjust according to a sitting or lying position, it finds it harder to accommodate to the outer space gravity.
This may be determined by the fact that in space, the fluid system has no posture-related parameters to which it can relate.
The results were gathered after the scientists studied the MRI scans executed before and after 7 long-term ISS missions.
These were also compared with short-term mission results and also high-resolutions orbit scans.
According to Dr. Alperin, these tests were vital in determining the cause of the astronaut visual impairment.
As the exact cause of this syndrome is now known, scientists can proceed to look for and determine treatments and cures.
This will offer an early on chance of repairing any possible irreversible damage to the astronauts’ eyes. A flattening of the eye globe would determine the astronauts’ becoming farsighted, or hyperopic.
Currently, NASA reported to be studying the VIIP and its now known causes so as to develop countermeasures.
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