Long-term results of Krupin-Denver valve implants in filtering surgery for neovascular glaucoma

The long-term results obtained with the Krupin eye short valve shunt in 28 eyes with neovascular glaucoma were retrospectively analyzed by means of Kaplan-Meier survival curve. The preoperative intraocular pressures (IOPs) ranged from 28 to 62 mm Hg (mean, 36.8+/-5.8 mm Hg). Success was considered an IOP of less than 22 mm Hg and greater than 5 mm Hg without medication (complete success) or with medication (qualified success) without additional glaucoma filtering surgery or devastating complications. Postoperative success was obtained in 10 out of 28 eyes after a mean follow-up period of 58.4+/-23.02 months (range, 10-108 months). The 3- and 6-year life table success rates were 66 and 34%, respectively. Early complications were: shallow or flat anterior chamber (15 patients, 53.6%), hypotony (16 patients, 57.1%), hypertony (7 patients, 25%), serous choroidal effusion (7 patients, 25%), fibrinous uveitis (5 patients, 17.9%), blockage of the intracameral portion of the tube by fibrin (5 patients, 17.9%), choroidal hemorrhage (2 patients, 7.1%). Late complications were: external conjunctival bleb failure (12 patients, 42.9%), blockage of the intracameral portion of the tube by fibrovascular tissue (5 patients, 17.9%), cataract (2 patients, 7.1%), bullous keratopathy (2 patients, 7.1%), external erosion of the Silastic valve (2 patients, 7.1%), phthisis bulbi (2 patients, 7.1%). Mortality during long-term follow-up was high in our series. The complications of an underlying diabetes mellitus were the most common causes of death (15 out of 22 patients). The high mortality of patients subjected to valve implantation makes it difficult to interpret the results of long-term studies. However, the valve implant is still today an alternative surgical procedure for controlling IOP in eyes with neovascular glaucoma that have visual potential.