Human cornea: oxygen uptake immediately following graded deprivation.

A micropolarographic system was used to measure the flux of oxygen crossing the tear epithelial interface of the human cornea just following stabilized exposure to eight oxygen atmospheres ranging from 0% to 20.9%. In all, 336 measurements were made on the corneas of seven young healthy subjects. The rate coefficients of their immediate postexposure oxygen uptakes were found to increase nearly linearly over the atmospheric range of 20.9% (air) down to about 1.5%. Below that level, however, a marked increase in the immediate recovery rate coefficient occurred, suggesting that at least two oxygen demand phases can be distinguished for the aerobically dependent pathways of the cornea.