Management of glaucoma implants occluded by vitreous incarceration

PURPOSE: To review the authors' experience in the management of aphakic or pseudophakic patients without an intact posterior capsule who had undergone glaucoma implant surgery complicated by vitreous incarceration in the tube, resulting in increased intraocular pressure or combined rhegmatogenous and tractional retinal detachment. METHODS: Retrospective review of the clinical features, treatment, and outcomes of eight patients who had vitreous incarceration in a glaucoma implant drainage tube. In each patient, a model 425 (7 patients) or model 350 (1 patient) Baerveldt glaucoma implant was used. RESULTS: Vitreous incarceration in the tube was first diagnosed 1 day to 49 weeks after surgery (mean, 7.5 weeks; median, 1 week). The interval between glaucoma implant surgery and pars plana vitrectomy ranged from 22 to 365 days (mean, 125 days). Before management with pars plana vitrectomy or neodymium:yttrium-aluminum-garnet laser vitreolysis, intraocular pressure ranged from 25 to 62 mm Hg (mean, 40 mm Hg). Four patients were initially treated with neodymium:yttrium-aluminum-garnet laser vitreolysis, which was successful in only one patient. Six patients were successfully treated with pars plana vitrectomy, and one patient declined surgery. Follow-up after treatment of the incarceration ranged from 5 weeks to 15 months (mean, 8.3 months). After pars plana vitrectomy, intraocular pressure ranged from 9 to 24 mm Hg (average, 14 mm Hg). Postoperative visual acuity remained within one line of the preoperative visual acuity in each of the six patients undergoing pars plana vitrectomy. CONCLUSIONS: Pars plana vitrectomy is effective in managing vitreous incarceration in glaucoma implant tubes. Previous anterior vitrectomy does not prevent incarceration.