Prostanoids in rabbit aqueous humor: effect of laser photocoagulation of the iris.

The authors measured concentrations of prostanoids (prostaglandin-like substances) in aqueous humor from normal pigmented rabbit eyes and from those subjected to argon laser photocoagulation of the iris. The predominant prostanoids quantitatively were prostaglandin E2 (PGE2), PGF2 alpha, and PGD2 with minor amounts of 6-keto-PGF1 alpha and thromboxane B2. In all cases, concentrations of prostanoids in laser-treated eyes were substantially greater than those in normal eyes. This finding was particularly striking in the case of PGE2 which increased 60-fold from 87 pg/ml to 5.5 ng/ml after irradiation. Concentrations of prostanoids following photocoagulation were related to the number of administered laser lesions and prostanoid release was associated with an initial hypertensive response and disruption of the blood-aqueous barrier.