VOIR - Visual scOpe In Reduced gravity

Paper number

IAC-05-A1.P.16

Author

Mr. Jeeshan Chowdhury, University of Alberta, Canada

Coauthor

Ms. Meghan Grant, McGill University, Canada

Coauthor

Mr. Benjamin Sanders, University of Waterloo, Canada

Coauthor

Mr. Farron Blanc, Canada

Year

2005

Abstract

The human body is exquisitely adapted to function in the 1G Earth environment. Consequently, when the cranio-caudal gravity vector is removed or reversed, a cephalad fluid shift occurs. Such shifting increases the hydrostatic pressure of the fluids in the upper body, both of the blood in the cardiovascular system, and of the aqueous humour, a clear liquid which fills the anterior and posterior chambers of the eye. Elevated intraocular pressure (IOP) has been documented in both spaceflight and parabolic flight, as well as in ground-based head-down tilt and inversion studies. This poses a serious concern, as increases in IOP are associated with reductions in visual field, as evidenced  in ground-based simulations as well as in studies of glaucoma (a disorder in which IOP is pathologically increased). Elevated IOP can also have permanent ocular sequelae: ischemic injury to the iris, corneal edema, and optic nerve damage. Given that an increased IOP has been demonstrated in parabolic flight, and that increases in IOP are associated with diminution of visual field, it follows that visual field may be adversely affected by even acute exposure to microgravity. We propose the hypothesis that reduction in visual field will be evident within the 20 second microgravity period afforded by parabolic flight.

This experiment will be flown as part of the 8thth ESA Student Parabolic Flight Campaign by a multidisciplinary team of students from 4 universities across Canada. Aboard the ESA Zero-G A300, an arc perimeter will be used to assess peripheral vision, as a measure of visual field.  Arc perimetery is a simple, rapid, and non-invasive test that can be conducted within the time constraint of a single 20-second parabola. The precise maneuvering performed by pilots – whether of aircraft or spacecraft – requires maximal visual acuity and scope. This study will demonstrate the viability of parabolic flight as a model for the further study of acute visual changes to gravity. A greater understanding of the effect of gravity on vision will allow for more accurate assessment of the need for preventive countermeasures to preserve optimal visual function in other situations in which acute changes in gravitational force are experienced.
Visual scOpe In Reduced gravity (VOIR)

Abstract document

IAC-05-A1.P.16.pdf

Manuscript document

IAC-05-A1.P.16.pdf (🔒 authorized access only).

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