Unilateral optic disc swelling in a fighter pilot.

Optic disc swelling occurs when there is an obstruction to axonal transport at the level of the lamina cribrosa. This may result from compression, ischemia, inflammation, or metabolic and toxic etiologies. Some of these etiologies may be life threatening and others may be self-limited. Thus, differentiating the different etiologies is important, albeit often difficult. We present a case of a 25-yr-old high-performance fighter aviator who presented with unilateral optic disc swelling 2 d after an F-16 flight, in which decompression was suspected. Visual acuity of the affected eye was decreased to 20/25, with enlarged blind spot and shallow arcuate scotomata on visual field testing. Pupil function, brightness intensity, and color vision were normal. Marked swelling of the entire optic disc, retinal flame-shaped hemorrhages, and engorgement of the retinal veins were seen. Since decompression sickness with nitrogen bubbles obstructing the optic nerve head vasculature was suspected, he was treated with hyperbaric oxygen. He rapidly improved, recovering full vision function within 6 d. No concurrent disease was found on extensive investigation. He returned to high-performance aviation 3 mo after onset of symptoms. No recurrence was seen during 3 yr of follow-up.