The relationship between corneal oxygen tension and hypoxic corneal edema.

Purpose: We sought to develop a direct, noninvasive measurement of tear oxygen tension behind soft contact lenses, and to use the tear oxygen tension data to determine if subjects with greater comeal oxygen consumption experience more comeal edema under hypoxic conditions. The relationship between tear oxygen tension and comeal thickness was also analyzed to determine if thicker comeas have higher metabolic rates.

Methods: Tear oxygen tension measurement was based on the quenching of a phosphorescent dye by oxygen.

Estimation of human corneal oxygen consumption by noninvasive measurement of tear oxygen tension while wearing hydrogel lenses.

Purpose: To devise a procedure for direct estimation of corneal oxygen consumption in human subjects.

Methods: Tear oxygen tension (PO2) was measured at the posterior surface of two standard hydrogel contact lenses (38% water, 0.2 and 0.