Initial clinical experience with the Ahmed Glaucoma Valve implant in pediatric patients

Objective: To evaluate the Ahmed Glaucoma Valve implant, an aqueous shunting device with a unidirectional valve mechanism, in patients younger than 18 years. Design: Prospective case series. Setting: Tertiary care hospital. Patients: Twenty-one consecutive patients younger than 18 years. The median age of patients was 4.8 years (range, 0.23-17.9 years). Intervention: Placement of an Ahmed Glaucoma Valve implant between April 1992 and April 1994. Main Outcome Measure: Time after surgery without failure. Success was defined as an average intraocular pressure less than 22 mm Hg for the last 2 follow-ups in eyes with preoperative intraocular pressure greater than 22 mm Hg, or an intraocular pressure that was lowered by at least 20% from preoperative values in eyes with preoperative intraocular pressure less than 22 mm Hg, and no additional glaucoma surgeries or visually devastating complications. Results: Cumulative probabilities of success at 12 and 24 months were 77.9%+/-8.8% and 60.6%+/-13.7%, respectively. One eye had a flat anterior chamber and suprachoroidal hemorrhage on the first postoperative day. No other eyes had flat or shallow anterior chambers that required reformation. In 3 eyes the implant extruded from underneath the conjunctiva and was removed. In 2 other eyes the average intraocular pressure for the last 2 follow-ups was greater than 22 mm Hg. In 1 eye with an intraocular pressure less than 22 mm Hg preoperatively, the intraocular pressure was not reduced by at least 20%, although the number of antiglaucoma medications was reduced. Conclusion: The 12- and 24-month success rates of the Ahmed Glaucoma Valve implant are similar to those of other implants when used in a pediatric population.