West Australian researchers have developed a breakthrough method to measure the brain fluid pressure in humans, which may reduce vision damage experienced by astronauts on long-haul space flights.

A cross-disciplinary team from the Lions Eye Institute and the International Space Centre at the University of Western Australia has developed a technique to measure the pressure in the brain fluid. The results may prove crucial to overcoming a type of blindness that frequently develops in astronauts on long-duration space flights, said co-author Associate Professor Danail Obreschkow from the International Centre for Radio Astronomy Research. “The so-called Space Associated Neuro-ocular Syndrome is one of the most serious risks for astronauts on long-duration flights and one that NASA identified as a significant challenge on future crewed missions to Mars,” he said.

Lions Eye Institute director and lead author Professor Bill Morgan said human bodies had evolved to counter the effects of gravity by pushing blood upwards into the head. “In microgravity, this can lead to an increased average pressure in the cerebrospinal fluid, which adversely affects the retina and deteriorates vision and other important functions.”

Until recently, this pressure could only be detected through invasive methods such as a lumbar puncture or skull burr hole, techniques which are painful, risky, and cannot be performed well in microgravity. The team has now developed a space-safe and non-invasive method to measure cerebrospinal fluid pressure changes. “All blood vessels experience tiny pulsations coming from the heartbeat. The strength of the pulsations in the tiny veins of the retina should, in principle, depend on the cerebrospinal fluid pressure,” Prof Morgan said.

In the study, a special eye camera was used to measure tiny pulsation changes while subjects were put into different positions on a tilt-table, mimicking the effects of variable gravity on the cerebrospinal fluid pressure. The tilt table experiments allowed the team to alter the cerebrospinal fluid pressure in small definite increments and led to the development of a handheld portable non-invasive device that can monitor intracranial pressure in microgravity conditions during space flights. The study was published in Nature in npj Microgravity.