Space shuttle flight environment induces degeneration in the retina of rat neonates.

Retinal degenerations can be promoted by many factors including ischemia, oxidative stress, and increased intraocular pressure. Damage to retinal neurons can be inhibited by neurotrophic factors such as PEDF, BDNF, and CNTF (Tombran-Tink and Barnstable, 2003). 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. Experimental evidence linking anomalies in visual perception with space flights has accumulated since the Apollo missions as have data suggesting pathological stimuli that disrupt retinal structure and function on earth are encountered in the space shuttle environment (Draeger 2000; Nicogossian et al., 1993). Orbital space flights cause physiological disturbances in humans including cephalad fluid shift, increased intraocular pressure, disruption of cardiovascular function and stress on the musculoskeletal system (Drummer 2000; Wang et al 1996; LeBlanc et al. 2000).