The effects of three topical anesthetics, cocaine, tetracaine (Pontocaine), and benoxinate hydrochloride, on oxygen flux across the tear-epithelial interface were compared in vivo at three dosage levels. Although flux depression did not accompany corneal analgesia in the case of benoxinate, it did occur with both cocaine and tetracaine. In both these cases, analgesia always led flux depression at onset, yet the interrelationship of the two phenomena was not so clearly defined during recovery.
Augsburger AR, Hill RM. Corneal Anesthetics and Epithelial Oxygen Flux. Arch Ophthalmol. 1972;88(3):305-307. doi:10.1001/archopht.1972.01000030307016