[Krupin's valve. Remarks on the surgery of glaucoma. Personal results apropos of 20 Krupin-Denver valves].

The literature concerning different kinds of draining implants used since the beginning of this century to increase the reliability of filtering operations to relieve glaucoma has been reviewed. The Krupin-Denver valve implant, which allows a filtration surgery with a pressure sensitive, unidirectional valve implant function drew the author's attention. This device consists in an open supramid tube sealed to a silastic tube ending with a slit valve which opens under a 11 to 14 mmHg intra ocular pressure. The supramid tube is inserted 1 to 4 mm long into the anterior chamber from the corneoscleral limbus, and the silastic tube is set under a scleral flap. Personal results are exposed from february 1981 to december 1983, 15 eyes have been treated (5 neovascular glaucomas, 5 glaucomas in aphakia, 4 congenital glaucomas and one chronic glaucoma). After mean follow up time of 13 months (1 to 34 months), the Krupin valve insertion controls the intraocular pressure in 14 eyes, without antiglaucoma medication in 5, and 7 cases are controlled with an additional local therapy, and further 2 cases with a general treatment. In the discussion, the improvements brought by this valve implant are studied facing the three great reasons of failure in the filtering operations as defined in 1980 by Molteno and Cairns: immediate post surgical hypotony, blockage of the internal end of the draining fistula, blockage of the external end of the draining fistula.