Objective: To evaluate the safety and efficacy of Ahmed glaucoma valve implantation for the management of glaucoma associated with chronic uveitis.
Design: Retrospective, noncomparative case series.
Participants: Nineteen patients (21 eyes) with chronic uveitis underwent Ahmed glaucoma valve implantation for uncontrolled glaucoma between 1995 and 1998.
Intervention: All patients had their uveitis controlled before surgery via immunomodulatory therapy. Ahmed glaucoma valve implantation was performed. Immunosuppression was continued in the early postoperative period for strict control of inflammation.
Main outcome measures: Control of intraocular pressure (IOP). A secondary outcome measure was the number of antiglaucoma medications required to achieve the desired IOP. Visual acuity and complications associated with the surgery were monitored.
Results: The postoperative follow-up averaged 24.5 months. At the most recent visit, all 21 eyes had IOPs between 5 and 18 mmHg. The average pressure reduction after Ahmed glaucoma valve implantation was 23.7 mmHg. The average number of antiglaucoma medicines required to achieve the desired IOP was reduced from 3.5 before surgery to 0.6 after surgery. No eye lost even a single line of Snellen acuity at the most recent postoperative visit. Two eyes developed hypotony in the course of follow-up. One resolved without specific intervention, and the other eye required two autologous blood injections and tube ligature to correct the hypotony. One eye underwent Ahmed glaucoma valve replacement for abrupt valve failure. Two eyes underwent penetrating keratoplasty for reasons believed to be unrelated to the glaucoma surgery. Kaplan-Meier life-table analysis showed a cumulative probability of success after Ahmed glaucoma valve implantation of 94% at 1 year.
Conclusions: Ahmed glaucoma valve implantation can be an effective and safe method in the management of uveitic glaucoma. The authors hypothesize that control of the patients' uveitis, through preoperative and long-term postoperative immunomodulatory therapy, may have contributed to the success rate reported herein.