GLAUCOMA DRAINAGE DEVICE AND PENETRATION KERATOPLASTY: GRAFT SURVIVAL AND IOP CONTROL

Francisco Fantes M.D, Claudia Arroyave M.D, Ingrid Scott M.D and Tim Murray M.D

Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami, Miami-Florida, USA

Objective: To investigate corneal graft survival rates and intraocular pressure (IOP) control in patients following penetrating keratoplasty (PK) and glaucoma drainage device (GDD) implantation.

Design: Consecutive case series.

Participants: All patients who underwent PK and GDD implantation at the Bascom Palmer Eye Institute between January 1, 1993 and October 31, 1998. Patients with less than 1 year of follow-up were excluded.

Methods: Consecutive case series.

Main outcome Measures: Graft clarity and IOP control.

Results: Of the 72 patients identified, 47 (65%) underwent combined PK and GDD implantation, and 25 (35%) underwent GDD placement following PK, in a time of 2 to 30 months, median 13 months. The GDD was placed in the anterior chamber in 54 (75%) patients and in the vitreous cavity in 18 (25%). The preoperative IOP was 5 to 21 mm Hg with or without antiglaucoma medications in 16 (30%) of patients with the GDD implanted in anterior chamber and 4 (22%) in patients with the GDD placed in vitreous cavity.

At 1 year following GDD implantation, the graft was clear in 26 (48%) patients with the GDD in the anterior chamber compared with 15 (83%) patients with the GDD in the vitreous cavity (p<0.013). Forty-eight (89%) patients with the GDD in the anterior chamber and 18 (100%) of patients with the GDD in the vitreous cavity had IOP between 5 to 21 mm Hg with or without antiglaucoma medications (p<0.33). The mean reduction in IOP, 1 year postoperatively, was 12 mm Hg among patients with the GDD in the anterior chamber, compared with 17 mm Hg among patients with the GDD in the vitreous cavity (p=0.13)

Conclusions: Corneal graft survival at 1 year is significantly higher among patients with the GDD implanted in the vitreous cavity compared with the anterior chamber. The IOP was significantly lower at 1 year postoperatively compared to preoperatively in both groups, although the IOP was lower in patients with the GDD placed in the vitreous cavity. There was no significant difference in corneal graft survival or IOP control between patients with the GDD implanted concurrently with the PK versus following the PK.