Collaborative effort focuses on safety, vision health of astronauts
Space is a hostile environment for the human body. We are all aware of the great risks taken in being rocketed into space and returning to Earth, with several memorable tragic accidents. Once in space and safely into the International Space Station, there remain many physiologic challenges that impact nearly every part of the body.
The study of these challenges to the health of our astronauts is a joint effort between NASA and the National Space Biomedical Research Institute (NSBRI), both in Houston. The NSBRI is housed in close proximity to the Baylor School of Medicine and collaborates closely with that prestigious institution and several others, including Johns Hopkins, Harvard, Stanford and the like. The NSBRI also can cast a wider consultation net to try to resolve challenging issues facing astronauts. The so-called “Vision for Mars” initiative is one such example.
NASA has been challenged to put a man or woman on Mars in the “Mission to Mars” project by 2030. If accomplished, it will be an amazing technical feat, requiring several ever larger orbits around the Earth followed by an escape from Earth’s gravity with propulsion to Mars, a recapturing of the spacecraft by the gravity of Mars, ever smaller orbits around Mars, followed by a landing. Then, the whole thing in reverse. It is estimated that the round trip, barring any unforeseen issues, will take up to 950 days.
To the great credit of our astronauts, they are cognizant of the risks in their profession and willing to accept them to complete the Mission to Mars. These risks, once safely in space, include continuous exposure to cosmic radiation from which they cannot be shielded, as well as many physiologic challenges associated with the microgravity environment. Past research has led to the use of blue light to positively impact sleep, as sleep deprivation can be devastating to the human psyche. Muscle and bone wasting has responded to exercises using large muscle resistance exercises. Added to these are swelling of the head and the visual changes discussed in this issue’s cover story, currently labeled as visual impairment and intracranial pressure (VIIP) syndrome.
It was a great honor to be selected by the NSBRI to consult in the Vision for Mars effort along with my colleagues Eugene de Juan, MD, Kuldev Singh, MD, Steve Schallhorn, MD, and John Berdahl, MD. Several industry luminaires are also involved, and the selection was spearheaded by Randy McDonald of Magnum Group and Dorit Donoviel of NSBRI. We were all briefed at the 2014 American Academy of Ophthalmology meeting and then given a disk with all the case histories and data accumulated to now. We then independently studied the issues and presented to a combined group of NASA and NSBRI scientists, executives and astronauts at NSBRI headquarters in Houston on Nov. 5 and 6, 2014.
After reviewing all the data, I was impressed that male astronauts who were emmetropic seemed to be at greater risk. I performed a literature search and found a similar syndrome on earth called “idiopathic benign progressive hyperopia with choroidal folds and papilledema” that seemed quite similar to the space/microgravity-induced VIIP syndrome. Of interest, the Earth-based syndrome also occurs almost exclusively in men. On the positive side, the VIIP syndrome to date has not resulted in any permanent loss of best corrected vision, which is also the case in the Earth-based syndrome as well. This is reassuring, but the hyperopic shift can be permanent, and if an astronaut suffers VIIP on one space trip, it nearly always recurs on a subsequent trip, and the hyperopic shift, choroidal folds and optic nerve edema can be additive.
One interesting thought that occurred to me is to select slightly myopic, pre-presbyopic, lean body mass women for the Mission to Mars, as they appear for some reason to be less likely to develop the VIIP syndrome. Of course, the selection criteria for the appropriate astronauts to send to Mars include many other factors, including education, training and the psychological stamina to survive for so many days in a demanding and stressful environment. Fascinating to me, at one NSBRI briefing dinner with an experienced and now retired commander of four missions was the question of what gender astronauts to send on such a long mission. It could be six men, six women or three couples. I have found myself thinking about the challenges in this decision more than once. With whom would I want to spend 500 days in space, especially if it is a multinational team?
The NSBRI Vision for Mars project is ongoing, and any interested ophthalmologist, scientist or industry colleague is welcome to offer advice and suggestions. Dorit Donoviel at NSBRI is the appropriate contact person.
Three studies have now been funded to attack the problem: one to develop enhanced diagnostics to better study changes in the optic nerve and choroid (Annidis), one for an adjustable spectacle lens to correct the progressive hyperopic shift if it occurs (Web Vision Centers Group) and one to look at a potential preventive treatment utilizing pressurized goggles (Equinox LLC). In the best of all worlds, these funded studies will advance the safety of the Mission to Mars, but also result in useful technologies for us Earth-bound doctors and our patients.
I was impressed by the quality and dedication of the leadership, scientists, physicians and astronauts at NASA and NSBRI and their careful evidence-based approach to reducing the risk of space travel for our astronauts. It has been an amazing experience and a special honor to be a small part of this extraordinary Vision for Mars project in support of the even greater Mission to Mars.