Effects of ultraviolet radiation on the oxygen uptake rate of the rabbit cornea.

Ultraviolet radiation (UVR) has been demonstrated to be involved in a number of adverse ocular effects. One aspect of UVR-induced corneal stress only recently documented is an alteration of epithelial energy metabolite levels. In this study, in order to examine wavelength and dose dependency issues concerning metabolic effects of UVR, exposures were made at four different wavelengths (290, 300, 310 and 360 nm) and five different mean radiant exposures (0.05, 0.10, 0.15, 0.20, and 0.25 J.cm-2). Pre- and postexposure levels of relative metabolic activity of the corneal epithelium were monitored in vivo by recording the corneal oxygen uptake rate with a micropolarographic electrode. A paired difference analysis demonstrated a decrease in relative corneal metabolic activity that was both wavelength- and dose-dependent. These relative metabolic effects provide some insight toward the understanding of underlying damage mechanisms, and imply a broader radiant energy susceptibility range of the eye than previously thought.