Intraocular Pressure Control and Corneal Graft Survival After Implantation of Ahmed Valve Device in High-Risk Penetrating Keratoplasty

Abstract

To analyze the control of intraocular pressure (IOP) and corneal graft survival after implantation of Ahmed glaucoma device (AGD) in eyes that had high-risk penetrating keratoplasty (PK). This is a retrospective noncomparative case series of 59 eyes that had high-risk PK and underwent AGD insertion. The primary outcome measures are the control of IOP between 6 and 21 mm Hg and corneal graft survival. The secondary outcome measures are risk factors associated with IOP control and corneal graft survival. The mean IOP reduced significantly after the AGD procedure (26.45 ± 6.8 mm Hg preoperatively vs. 16.85 ± 7.4 mm Hg, 16.95 ± 4.6 mm Hg, 17.97 ± 5.7 mm Hg, 15.78 ± 5.2 mm Hg, and 15.59 ± 5.5 mm Hg, at 1 month, 6 months, 1 year, 2 years, and at the last follow-up postoperatively; P < 0.0001). Over a median follow-up of 78 months (range, 9-175 months) after AGD insertion, IOP control was successful in 44 eyes (75.8%). IOP control was successful in 96% of the eyes at 1 year, 87% at 2 years, 83% at 3 years, and 83% at 5 years. The percentage of clear corneal grafts after 1, 2, 3, and 5 years following the AGD insertion were 87%, 77%, 65%, and 47%, respectively. Further surgery after AGD insertion was associated with 1.79 times greater risk of failure of IOP control. AGD was effective in controlling the IOP associated with high-risk PK over a 5-year period. Postvalve surgery doubles the risk of failure of IOP control.