From today’s Gazette, apparently originally from the Washington Post.
This is scary news. Eyesight is not something to risk, however lofty the goal.
Sildenafil inhibits an enzyme known as PDE-5 inhibitors, which are generic brand viagra unica-web.com utilized to treat male forsakenness (erectile brokenness). Kamagra contains Sildenafil which is able to work effectively by inhibiting an enzyme PDE5 which in turn, improves the blood flow in the body. purchase cheap viagra unica-web.com At Rxdrugonlinestore, we do our best to give the customer a pleasant unique online shopping experience to order cialis 10mg . The first Indian company, Ajanta Pharma produces Kamagra, the get cialis cheap is the second largely selling ED medicine in the world.
In 2005, astronaut John Phillips took a break from his work on the International Space Station and looked out the window at Earth. He was about halfway through a mission that had begun in April and would end in October. When he gazed down at the planet, the Earth was blurry. He couldn’t focus on it clearly. That was strange — he’d always had 20/20 vision. He wondered: was his eyesight getting worse? “I’m not sure if I reported that to the ground,” he said. “I think I didn’t. I thought it would be something that would just go away, and fix itself when I got to Earth.” It didn’t go away. During Phillips’ post-flight physical, NASA found that his vision had gone from 20/20 to 20/100 in six months. Phillips got MRIs, retinal scans, neurological tests, and a lumbar puncture. The tests showed that not only had his vision changed, but his eyes had changed as well. The back of his eye had got flatter, pushing his retina forward. He had choroidal folds, which are like stretch marks on the back of the eye. His optic nerve was inflamed. Phillips became the first widely recognized case of a mysterious syndrome that affects 80 per cent of astronauts on long duration missions in space.
THE SYNDROME
Visual Impairment Intracranial Pressure syndrome (VIIP) is named for the leading theory to explain it. On Earth, gravity pulls bodily fluids down toward the feet. That doesn’t happen in space, and it’s thought that extra fluid in the skull increases pressure on the brain and the back of the eye. At first, NASA thought that Phillips was an isolated case. But then researchers found evidence of VIIP in other astronauts. VIIP has now been recognized as a widespread problem, and there has been a struggle not only to understand its cause, but to study it at all. The theory that fluid builds up in the skull during space flight hasn’t actually been tested. The only proven methods of measuring intracranial pressure are invasive: a lumbar puncture or drilling a hole into the skull. “There’s the risk for infection and just doing the procedure, quite frankly, in space is difficult,” said J.D. Polk, a senior flight surgeon at NASA. “Having to anchor somebody and do a spinal tap in space is not something we would relish.”
RADICAL APPROACH
Michael Barratt, the former head of NASA’s Human Research program and space medicine specialist, is arguing for a radical approach to the problem. Barratt is also an astronaut. While he was on a six-month mission on the space station in 2009, he noticed his vision getting worse. He and a crewmate, Bob Thirsk, were both medically trained, and they decided to do something about it. “We’re thinking to ourselves, are we not physicians?” Barratt said. “So we did ophthalmoscopic exams on one another.” They both found hints of a swollen optic nerve. After NASA sent up more imaging equipment, they discovered the classic VIIP syndrome in one another: the flattening of the eye shape and optic disc edema. Barratt thinks solving the puzzle of VIIP is going to take testing intracranial pressure in space, even if that means an invasive procedure. One option is an intracranial probe that would be surgically implanted months before flight and allow pressure to be measured at different points during space flight. “This is one of those times I think aggressive science is extremely warranted,” Barratt said.
MARS BECKONS
Before a human trip to Mars, which NASA says it wants to achieve by the 2030s, researchers agree that VIIP needs to be understood much better. Mars is a six- to nine-month journey away. VIIP could be the first sign of greater dangers to the human body from microgravity. Richard Williams, the chief health and medical officer at NASA, agrees that what we don’t know about VIIP still poses the biggest threat. Ironically, one of the only ways to get more knowledge is to spend more time in microgravity. “The longer we stay in space, the more we’re going to learn,” Williams said.