Retinal Oxygen Utilization Measured by Hyperbaric Blackout

Abstract

Lanphier¹has observed that the loss of visual function following occlusion of ocular circulation (as by ophthalmodynamometry) occurs less rapidly if the subject is breathing 100% oxygen at 3 atmospheres pressure. This blackout of visual function is similar to that reported by pilots under positive g conditions and recently investigated by Jaeger et al using a plethysmographic goggle.²For subjects breathing 100% oxygen, theoretical arterial oxygen concentrations may be calculated for any pressure.* These concentrations may then be compared with the time to blackout of visual function at various high atmospheric pressures and a rate of oxygen utilization thereby determined. Such determinations and calculations are the subject of this paper. Method Four normal young subjects whose ophthalmic artery pressures had previously been determined by both the Bailliart ophthalmodynamometer and the transducer ophthalmodynamometer supplied with the Mueller tonography apparatus were selected. The left eye was occluded with an adhesive