In 1938 Evans and McFarland1 showed a relation between oxygen deprivation and angioscotomas. They demonstrated a widening of the defects, the extent of which varied with the degree of oxygen deprivation. They suggested that these changes arose because of a relative anoxemia at the synapses of the first and second retinal neurons.
According to Peters and Van Slyke,2 the hemoglobin in the arterial blood of persons free from disorders of the respiratory tract has an oxygen saturation of approximately 95 to 96 per cent at sea level. The additional amount of oxygen that can be carried by the blood is small even when the oxygen tension in the inspired air is elevated. It corresponds at most to the remaining 5 per cent of the oxygen-carrying capacity of hemoglobin plus a small amount physically dissolved in the plasma (which is proportional to the arterial oxygen tension). It is generally
ROSENTHAL CM. CHANGES IN ANGIOSCOTOMAS ASSOCIATED WITH INHALATION OF OXYGEN. Arch Ophthalmol. 1939;22(3):385–392. doi:10.1001/archopht.1939.00860090051005
Coronavirus Resource Center
Customize your JAMA Network experience by selecting one or more topics from the list below.
Create a personal account or sign in to: