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 an d tractional retinal detachment. Methods: Retrospective review of the clinical features, treatment, and outc omes 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 p atient) 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 betwee n glaucoma implant surgery and pars plana vitrectomy ranged from 22 to 365 days (mean, 125 days). Before management with pars plana vitrectomy or neod ymium:yttrium aluminum-garnet laser vitreolysis, intraocular pressure range d from 25 to 62 mm Hg (mean, 40 mm Hg). Four patients were initially treate d with neodymium:yttrium-aluminum-garnet laser vitreolysis, which was succe ssful in only one patient. Six patients were successfully treated with pars plana vitrectomy, and one patient declined surgery. Follow-up after treatm ent 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 li ne of the preoperative visual acuity in each of the six patients undergoing pars plana vitrectomy. Conclusions: Pars plana vitrectomy is effective in managing vitreous incarc eration in glaucoma implant tubes. Previous anterior vitrectomy does not pr event incarceration.