Space Flight Environment Induces Degeneration in the Retina of Rat Neonates

Abstract

Retinal degenerations can be promoted by many factors including ageing, ischemia, fluctuation in oxygen tension, oxidative stress, and increased intraocular pressure. We present new evidence that the environment encountered in space shuttle flight can also disrupt normal retinal development and mimic stimuli that induce retinal degenerations on earth. There is experimental evidence linking anomalies in visual perception with space flights since the Apollo missions (Phillpot et al., 1978; Newberg and Alavi, 1998). There is also strong evidence that pathological stimuli that disrupt retinal structure and function on earth are encountered in the space shuttle environment as well. Orbital space flights cause physiological disturbances in humans including cephalad fluid shift (Hoffler et al., 1977; Drummer, 2000), increased intraocular pressure (Mader et al., 1990; Draeger, 2000) disruption of cardiovascular function (Wang et al., 1996) and stress on the musculoskeletal system (Lane and Feedback, 2002; LeBlanc, 2000).