Influence of laser irradiation on endogenous hyaluronan in rabbit iris andaqueous humor

Purpose: To monitor changes of endogenous hyaluronan in the iris tissue and aqueous humor after an isolated trauma to the iris by argon laser irradiat ion of the anterior surface of the iris. Methods: Iris and aqueous hyaluronan concentrations in rabbit were measured with a radiometric assay at different time points after laser irradiation. Results. Total hyaluronan content in iris tissue increased 3-fold to a peak concentration of 71-72 mug/g at I and 2 days after laser treatment. Aqueou s hyaluronan increased to a maximum of about 1.6 mug/ml at 2 h and 12 h aft er laser irradiation of the iris. Conclusions: The iris tissue responds with increased hyluronan synthesis to an isolated iris argon laser irradiation and it seems to be the most impor tant source of aqueous hyaluronan.