The Ahmed valve in refractory pediatric glaucoma

PURPOSE: To evaluate the efficacy of the Ahmed Glaucoma Valve implant in pediatric patients with refractory glaucoma. METHODS: A retrospective chart review was conducted of 27 eyes from 23 consecutive pediatric patients (younger than 18 years) with refractory glaucoma treated with Ahmed Glaucoma Valve implant placement. The main outcome measure was time after surgery without failure. Success was defined as an intraocular pressure of 21 mm Hg or less without visually devastating complications or additional glaucoma surgery (exclusive of tube revision). Previous cycloablation, which was present in a subset of eyes, was examined as a possible influence on postoperative intraocular pressure control, glaucoma medication dependence, and surgical success. RESULTS: The median patient age was 4.8 years (range, 0.3 to 16.8 years), with a follow-up of 3 to 31 months (mean, 12.6 +/- 8.2 months). Intraocular pressure was reduced from a preoperative mean of 32.8 +/- 7.5 mm Hg to 16.7 +/- 5.4 mm Hg at 18 months postoperatively, with an overall success rare of 85.2% at last. follow-up. Cumulative probabilities of success by Kaplan-Meier analysis were 90.6% at 12 months and 58.3% at 24 months. Compared with those that did not undergo previous cycloablation, eyes that had undergone previous cycloablation had, a lower mean postoperative intraocular pressure at 3- and 6-month follow-up (P < .001 and P = .057, respectively) and required fewer glaucoma medications at postoperative examination time points up to 18 months (P less than or equal to .01 at each time point). Fifteen eyes (56%) required glaucoma medications after surgery. The most common complication was corneal-tube contact, which occurred in five eyes (18.5%). One eye with a wound leak required anterior chamber reformation. Retinal detachment occurred in one aphakic eye 2 years postoperatively, resulting in loss of vision. One eye with neovascular glaucoma required enucleation after an enlarging (presumably preexisting) medulloepithelioma was discovered. CONCLUSIONS: Ahmed Glaucoma Valve implantation is a useful therapy for the treatment of refractory pediatric glaucoma, and it may be safely used in a subgroup of eyes with uncontrolled intraocular pressure despite previous cycloablation procedures. (C) 1999 by Elsevier Science Inc. All rights reserved.