The concentration of copper ([Cu]) in the extracellular fluid compartments of rabbit eyes was found to increase approximately 30-fold during experimental uveitis, generally paralleling increases in [protein]. However, during the recovery phase the decrease in [Cu] lags behind the decrease in [protein]in some rabbits, suggesting the presence of abnormally high levels of non-protein-associated Cu. Intravitreal injection of CuSO4(6μg of Cu/eye) causes an inflammatory response and evidence of tissue damage. A better understanding of trace element metabolism is clearly required to further elucidate the mechanism of ocular inflammation and associated tissue damage.