Corneal responses to acid measured in vivo.

With the use of a micropolarographic system, the effects of a series of unbuffered hydrochloric acid concentrations on oxygen uptake by the corneal epithelium of rabbit were measured in vivo. Based on an exposure model of 60 s, followed by a saline rinse, concentrations of 0.50 N and less were found to produce initial flux variations, which did, however, return to near normal levels within 20 min. But a concentration of 0.75 N for that duration was found to produce an abrupt and sustained decrease in oxygen uptake. This time-strength combination was noted to be substantially greater than that required to produce a similar effect with alkali. A concentration of 1.0 N HCI produced responses indistinguishable from a cornea denuded of its epithelium.