Pars plana tube insertion of glaucoma drainage implants and penetrating keratoplasty in patients with coexisting glaucoma and corneal disease.

Abstract

To determine the efficacy and associated complications of glaucoma drainage implant (GDI) surgery with pars plana tube insertion and penetrating keratoplasty (PK) in eyes with glaucoma and corneal disease. Retrospective, interventional case series. All patients who underwent both GDI surgery with pars plana tube insertion and PK before September 1997 were included. The medical records of 34 consecutive patients (34 eyes) who had undergone GDI (Baerveldt, Pharmacia & Upjohn, Kalamazoo, MI; Molteno, IOP INC:, Costa Mesa, CA; Krupin, Hood Laboratories, Pembroke, MA; or Ahmed, New World Medical, Rancho Cucamonga, CA) insertion before, concurrent with, or after PK were reviewed retrospectively. All corneal grafts were clear before GDI surgery for patients who underwent glaucoma surgery after PK. Outcomes were evaluated using Kaplan-Meier life-table analysis. Clinical outcome assessment included corneal graft clarity, intraocular pressure (IOP), visual acuity, and identification of complications. Mean follow-up after completion of both GDI surgery and PK was 12.1 +/- 8.4 months (range, 0-31.8 months). Twelve- and 24-month life-table rates for complete success after both GDI and PK were 63% and 33%, respectively. Twelve- and 24-month life-table success rates for IOP control and corneal graft clarity were 85% and 62%, and 64% and 41%, respectively. Final postoperative visual acuity was the same as or better than (> or =2 Snellen lines) the preoperative level in 29 patients (85%). One or more posterior segment complications occurred in 15 (44%) patients. Pars plana tube insertion of GDIs is a reasonable option for patients who have undergone PK or in whom PK is anticipated, despite the need for a complete pars plana vitrectomy. Although complications related to limbal tube placement are avoided, the incidence of posterior segment complications may be higher for pars plana insertion. The potential for enhanced corneal graft survival with pars plana versus anterior segment tube placement warrants further investigation.