Long Term Graft Survival in Combined Ahmed Glaucoma Valve Implantation and Penetrating Keratoplasty

Abstract

Abstract: : Purpose: To assess the survival rate of corneal grafts and intraocular pressure (IOP) control after simultaneous penetrating keratoplasty and Ahmed glaucoma valve implantation (PK-AGV). Methods: Office charts and surgical records of 50 eyes of 49 patients that underwent PK-AGV at Long Island Jewish Hospital from August 1994 to April 1999 were retrospectively reviewed. Demographic information, corneal graft survival, visual acuity, IOP, and glaucoma medication use were recorded. Results: Thirty-nine eyes had greater than 1 year of follow-up and were available for analysis. All graft failures were included regardless of the number of months to failure. Mean age of the subjects was 72.6 +/- 11.5 years (range 40 -85 years). There were 18 men (46.2%) and 21 women (53.8%). The predominant pre-operative corneal diagnosis was pseudophakic bullous keratopathy (27/39 eyes, 69.2%). All patients had preexisting glaucoma. Primary open angle glaucoma was present in 24 patients (61.5%). Corneal graft survival by Kaplan-Meier estimation at one year and three years was 89.7% and 73.7%, respectively. Mean IOP was 24.7 +/- 9.4 mmHg (range, 12-50 mmHg) pre-operatively, 15.1 +/- 5.7 mmHg (range, 5-38 mmHg) at 1 year and 13.9 +/- 4.3 mmHg (range, 7-24 mmHg) at 3 years post-operatively. Mean number of glaucoma drops decreased from 2.6 +/- 1.1 pre-operatively to 1.1 +/- 1.1 at final follow-up. Pre-operative visual acuity of ≤ 20/400 was present in 36 of 39 eyes (92.3%). At final follow-up, the number of patients with ≤ 20/400 visual acuity had decreased to 23 (23/39, 59.0%) with 10 patients (25.6%) having visual acuity of 20/100 or better. Conclusions: PK-AGV in patients with preexisting glaucoma results in long-term corneal graft survival. Implantation of an Ahmed glaucoma valve at the time of penetrating keratoplasty results in significant and long-term IOP control, as well.

Keywords: transplantation • intraocular pressure • anterior segment