Combined pars plana vitrectomy and glaucoma drainage implant placement for refractory glaucoma

PURPOSE: To report visual acuity and intraocular pressure outcomes among patients who have undergone combined pars plana vitrectomy and placement of a glaucoma drainage implant. METHODS: The medical records of all patients who underwent combined pars plana vitrectomy and placement of a glaucoma drainage implant at the Bascom Palmer Eye Institute by one of the authors between January 1, 1990, and February 28, 1998, were reviewed. Forty patients (40 eyes) were identified, including 14 patients with neovascular glaucoma secondary to proliferative diabetic retinopathy or central retinal vein occlusion, 15 patients with other posterior segment disease, seven patients with secondary angle-closure glaucoma, and four patients with aphakia with ruptured anterior hyaloid face. Main outcome measures included visual acuity and intraocular pressure at 1 year postoperatively. RESULTS: At 1 year postoperatively, 31 (77.5%) of 40 patients had stable or improved visual acuity; three eyes (7.5%) had a final visual acuity of no light perception and three additional eyes (7.5%) were enucleated (because of chronic pain in two eyes and endophthalmitis in one eye). Mean preoperative intraocular pressure was 34 mm Hg and the median number of preoperative antiglaucoma medications was two. At 1 year postoperatively, mean intraocular pressure was 13 mm Hg and the median number of antiglaucoma medications was zero. Twenty- two patients (55.0%) achieved an intraocular pressure greater than 5 mm Hg and less than or equal to 21 mm Hg without antiglaucoma medication, and an additional seven patients (17.5%) achieved this level of intraocular pressure control with medication. Only one patient (2.5%) underwent further glaucoma surgery for uncontrolled intraocular pressure. CONCLUSIONS: Although combined pars plana vitrectomy and placement of a glaucoma drainage implant is often a successful management option in selected patients with refractory glaucoma, visual outcome may be poor because of severe underlying ocular disease and postoperative complications.