Modeling the electrophysiology of the corneal epithelium and its response to cellular injury.

A two-membrane equivalent electrical model was applied to the rabbit corneal epithelium. Single parameters were varied (with the other parameters kept constant) to generate equations predicting the electrical behavior of the corneal epithelium. Due to electrical feedback through the epithelial shunt, each transmembrane voltage is not solely a function of its own membrane parameters. The equations were evaluated with published data and the model successfully approximated the known electrical characteristics of the rabbit corneal epithelium. The principal site of voltage variation in the corneal epithelium is inferred from the slopes calculated from voltage scattergrams. Reduced shunt resistance results from injury to the corneal epithelium in vitro, or from hard contact lens wear in vivo.