[Goniotrepanation as a second fistulizing procedure (author's transl)]

Goniotrepanation was performed in 70 eyes as a second procedure following a fistulizing operation. Where there was a cicatrization of the bleb from the first intervention the tenon was removed at the same time. The results cover periods of observation of up to six years. Except in the early postoperative phase the removal of the tenon is of no importance for long-term pressure regulation and the formation of the bleb. Compared with the primary operation, pressure regulation was diminished. After an interval of four to six years 88% of the eyes were compensated, even though this was only accomplished without additional therapy in 35%. The creation of the largest possible intrascleral space is probably the deciding factor in the pressure regulation; the formation of this is favorably influenced by the preparation of a large, thin scleral flap with a flexible junction. This involved a slightly increased risk of postoperative complications as compared with the primary goniotrepanation procedure. Postoperatively the anterior chamber was flattened in 10 eyes and in one eye it disappeared completely, so that in three patients it had to be surgically reconstructed. However, since success in pressure regulation is dependent upon filtration, one should not forgo the advantage of a large intrascleral space allowing for slightly excessive filtration.