Cyclocryokoagulation. Sequelae of induced alterations and effect of a prostaglandin-inhibitor on the breakdown of the blood-aqueous barrier.

Histopathological changes following cyclocryokoagulation in a group of rabbits pretreated with acetylsalicyclic acid (ASA) were studied and compared with similar changes in a control group. As observed clinically, macroscopical and histological differences were only noted in the early phase after the procedure. In this phase, all operated eyes revealed an immense vascular response with edema, exudation and extravasation of blood cells. The treated animals, however, showed some reduction of tissue edema than the animals not treated. At a later stage there is an necrosis of the stroma with reduction of small vessels and tissue cells. The reparative process, tending to restore both epithelial and stromal lesions, begins already in the 3rd. week after cyclocryokoagulation. Neither the epithelial nor the stromal alterations differed significantly in any of the operated eyes at this stage. This indicates that ASA mainly affects an obviously prostaglandin-mediated acute vascular response. The disruption of the epithelial barrier may be aggravated by the subsequent stromal alterations, but does not seem to be influenced by ASA.