The effect of benzalkonium chloride on the electropotential of the rabbit cornea.

The effect of benzalkonium chloride on the electropotenial of the cornea has been examined. The anterior surface of the in vivo or in vitro cornea was exposed to various concentrations of the surfactant, from 0.005% to 0.02%, for either 1 or 2 min. The initial effect is a hyperpolarization lasting up to 30 sec, followed by a rapid fall in potential difference with a subsequent recovery. The degree of potential difference decrease and the recovery rate was dependent upon both the concentration of the detergent, and the exposure time. There is excellent correlation between the previous anatomical and physiological studies on tracer penetration across the in vivo and in vitro cornea and our present work. The data indicate that benzalkonium chloride acts by breaking down the physiological and anatomical diffusion barrier to solute and solvent which is located in the outer layer of the epithelium.