The time course of laser-induced disruption of the blood aqueous barrier in the rabbit.

The response of the blood aqueous barrier to a defined laser trauma was investigated in a series of seven groups with three pigmented rabbits in each group. The peripheral iris of the left eye was treated with the Argon laser (ten spots of 50-microns size with an energy of 100 mJ). The right eyes served as controls. The anterior chambers of both eyes were tapped at given time intervals after the laser coagulation to enable the analysis of the protein content of the aqueous humour and for the assay of the lactate dehydrogenase activity. Within 100 min after laser treatment a positive correlation between time and protein concentration in the anterior chambers of the treated eyes (r=0.77) and in the untreated eyes (r=0.79) was established. There was a significant response on the blood aqueous barrier in the untreated fellow eyes. The activity of the lactate dehydrogenase showed a significant increase 5, 70 and 100 min after laser trauma in the treated eyes only. The laser trauma induced a significant increase (alpha-0.01) in the intraocular pressures of the treated eyes, which persisted up to 70 min after treatment. The clinical implications of these findings are discussed.