KRUPIN EYE VALVE WITH DISK FOR FILTRATION SURGERY

Purpose: The authors evaluate a long posterior tube shunt device with a pressure sensitive valve for filtration surgery in eyes with recalci trant glaucoma. Methods: The device consisted of an anterior chamber t ube connected to an oval (13 X 18 mm) episcleral explant. The explant was designed to maximize the area of surrounding encapsulation while s till allowing implantation within one quadrant. A pressure-sensitive a nd unidirectional slit valve in the tube provided resistance to aqueou s humor flow. One-stage implantation without the use of restrictive su tures was performed in 50 eyes with various types of glaucoma unrespon sive to prior glaucoma surgery. Results: Mean (+/- standard error of t he mean) preoperative intraocular pressure (IOP) of 36.4 +/- 1.6 mmHg was reduced significantly (P < 0.001) to 8.3 +/- 1.3 mmHg on the first postoperative day. Mean anterior chamber depth (scale, 0-4+) was 3.4 +/- 0.1. Mean IOP 1 month after surgery was 14.1 +/- 1.3 mmHg. The imp lant was removed from four eyes due to IOP failure(l eye), external er osion (2 eyes), or endophthalmitis (1 eye). A suprachoroidal hemorrhag e occurred in one eye on the first postoperative day. Diplopia develop ed in one eye after surgery. Mean IOP at last follow-up examination (m ean, 25.4 +/- 2.4 months; range, 16-36 months) was 13.1 +/- 1.3 mmHg. Intraocular pressure was 19 mmHg or lower in 80% of the eyes, 59% of w hich were without adjunctive antiglaucoma medications. Conclusions: De sign features of the Krupin Eye Valve with Disk result in a large area of encapsulation in a single ocular quadrant which functions as an ex ternal reservoir for passage of aqueous humor. The valve portion facil itates maintenance of anterior chamber depth during the early postoper ative interval. This new therapeutic device can be effective in the lo ng-term control of IOP in glaucomatous eyes not responsive to prior fi ltration surgery with adjunctive antimetabolite therapy.