A new system for visualizing and recording changes in retinal circulation allows electromechanical remote focusing of a fundus camera while simultaneously viewing the retinal image on a television monitor, and recording changes on videotape and on film. Retinal circulatory collapse in the central optic disc region was observed during routine ophthalmodynamometry, and collapse appeared to be similar to that observed during blackout on the US Air Force School of Aerospace Medicine (USAFSAM) human centrifuge. In those subjects in which head level arterial pressure was measured during exposure sufficient to cause blackout, the collapse of the central retinal artery occurred at pressure levels which were apparently below intraocular pressure. Rhesus monkeys exposed to −40GZ acceleration for 60 seconds had a collapsed retinal vascular bed for periods up to 15 minutes postrun.
Leverett SD, Bailey PF, Holden GR, Cheek RJ. Fundus Cinephotography During Gravitational Stress. Arch Ophthalmol. 1970;83(2):223-231. doi:10.1001/archopht.1970.00990030225017