Prostaglandin E in rabbit aqueous humor after Nd-YAG laser photodisruption of the iris and the effect of topical indomethacin pretreatment.

Ocular changes (prostaglandin E, protein, pupil diameter, and intraocular pressure) induced by photodisruption of pigmented rabbit iris with neodymium-yttrium aluminum garnet (Nd-YAG) laser and the effect of topical indomethacin upon those changes were examined. Concentrations of prostaglandin E in laser-treated eyes (1,3,5,10, and 20 lesions) were substantially greater than those in normal eyes and were associated with an initial hypertensive response. This finding was particularly striking in the case of 20 lesions. In that case, concentrations of prostaglandin E increased 50-fold, from 99 pg/ml of control level to 5049 pg/ml 60 min after irradiation. Disruption of blood aqueous barrier measured by protein concentration, changes in intraocular pressure, and pupil diameter occurred at a similar dose range of laser application. Concentration of protein and changes in pupil diameter already were prominent at 15 min after laser treatment, and changes in intraocular pressure were prominent at 60 min. Indomethacin pretreatment abolished most of these responses, suggesting that acute reactions following photodisruption largely depended on prostaglandin synthesis in iris tissue.