Transient Visual Phenomena Associated with High G-Force Maneuvers

A 30-year-old male fighter pilot presented with intermittent peripheral vision loss experienced during flight. Initial examination disclosed 20/20 vision in the right and left eye with normal motility, intraocular pressure, and no afferent pupillary defect. Anterior and posterior slit lamp exam was within normal limits. Differential diagnosis for static and transient tunnel vision is discussed. The physics of G-force tolerance is reviewed including gray-out, black-out, and G-induced loss of consciousness (G-LOC). The pathophysiology related to poor perfusion of the peripheral retina, optic nerve head, and occipital lobe is explained via examples from the literature. The mechanics behind vitreoretinal interface injury due to negative g-force decelerations is presented. A study design for measuring dynamic visual field changes in a centrifuge utilizing a novel, portable visual field device is presented. Finally, preventive and treatment measures for G-induced vision changes are reviewed including centrifuge training, g-suits, Valsalva, seat design, and drones.

Presentation Date: 12/03/2020

Issue Date: 06/18/2021