[Experimental and clinical experiences with silicone catheters in fistulizing glaucoma surgery].

1. A historical revue of seton operations is presented, which were actually explored for the first time by Rollet in 1907. 2. The paramount importance of the selection of the appropriate material for the setons is stressed. 3. Ocular tolerance especially of silicone tubings has been investigated by animal experiments. Excellent tolerance of silicone intraocularly as well as subconjunctivally has been found. This fact confirms experimental investigations by other authors. 4. In animal experiments for the first time a surgical technique securing firm anchorage of a sole silicone tubing could be developed. Insertion of a silicone catheter was combined with thermal sclerostomy; ocular hypotony was not encountered. 5. A study exploring aqueous egress following the new surgical procedure has been conducted by means of injection of fluorescein into the anterior chamber. Various exit-sites of aqueous were recorded: diffuse outflow through the filtration cleft as well as the catheter lumen, and also via channels either within lymph vessels or secondary aqueous veins. 6. Aqueous outflow following the seton operation has also been studied by scintigraphic means; the first description of this method in glaucoma-operated eyes is presented. Applying this technique not only the existence of a filtering bleb is documented, but in addition the speed of aqueous transit through the filtering bleb was measured. This transit has been found to be a rapid one. 7. The clinical results of this type of seton operation do confirm the experimental evidence of excellent ocular tolerance of silicone tubings as well as the reliability of their firm anchorage. Postoperative tension with or without additional antiglaucomatous medication proved quite satisfactory. 8. The proposed surgical procedure is recommendable especially in patients exhibiting haemorrhagic glaucoma, were conventional methods are likely to fail in the majority of cases.