NASA medical researchers have found that the cardiovascular risk profile among male astronauts, although clinically normal, is higher compared with female astronauts, suggesting that men may have slightly stiffer blood vessels that may contribute to higher cerebral spinal fluid pressure in space. Overall, it appears men are more prone to developing vision problems in space. The cause of this condition is unknown, but this Earth-bound syndrome and the space-induced changes seem similar. The condition is called “idiopathic benign progressive hyperopia with choroidal folds and papilledema” and has been reported in a small number of patients not exposed to space travel. Through a literature search, Lindstrom and others have found rare instances of a similar syndrome on Earth with progressive hyperopic shift, papilledema and choroidal swelling. “This presents additional requirements for corrective lenses inflight for astronauts as they try to do their work,” Lindstrom said. The cause is swelling of the choroid, flattening of the globe shortening the axial length of the eye and sometimes associated disc edema. “After 8 to 12 weeks in space, some astronauts start to shift hyperopic, developing blurry vision at distance,” Lindstrom said. Lindstrom is one of a handful of ophthalmologists and industry leaders with diverse backgrounds who convened twice last fall as part of a special advisory group to the National Space Biomedical Research Institute (NSBRI) in Houston, a NASA-funded consortium. This can result in disc edema and choroidal swelling.” The core etiology is probably related to elevated venous pressure, which then causes an elevated cerebral spinal fluid pressure. But in weightlessness, not only is this assist absent, but up to 2 L of fluid shifts headward from the lower body. “In the head, gravity assists blood return to the heart. “When you are in space, you do not have gravity like we do on Earth,” OSN Chief Medical Editor Richard L. The hope is that in-flight monitoring and treatments will counter the detrimental effects of living in essentially a gravity-free environment. NASA is banding together with thought leaders in ophthalmology and industry to try to remedy vision problems encountered by astronauts in space for lengthy periods of time. If you continue to have this issue please contact to Healio
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