[The effects of a gigant-pulse-laser upon the iris of the pigmented rabbit eye (author's transl)].

The eyes of 10 pigmented rabbits were irradiated by a Q-switched Nd:YAG laser. The pulse energy delivered to the right eye was 187 mJ while the left eye was irradiated with 58 mJ. The pulse duration in both cases was 25 ns. The destructive effects were analysed for two different positions of the focus. In the upper half of the eye the focus was positioned at the anterior iris surface. In the lower half it was adjusted near the pigment epithelium. The eyes were analysed by electron microscopy at intervals of 15 minutes to 128 days after irradiation. The immediate effects were found to depend from the position of the focus but less from pulse energy. At later phases, tissue reaction depends from pulse energy. -- Scarification, at the lower energy level, is almost complete after 32 days. At the higher energy level, degenerative processi are setting in; 3 days after irradiation a progressing iris atrophy is observed which has not yet faded at the 128th day.