Ahmed Valve Tube Extension in Pediatric Glaucoma

Abstract

PRéCIS:: Ahmed valve tube extender showed good long-term outcomes for retracted tubes in pediatric glaucoma. The procedure is safe with limited complications.

Purpose: To analyze the long-term outcomes of Ahmed valve tube extension in pediatric glaucoma patients.

Patients and methods: This study analyzed the records of all children who underwent surgery involving extension of a pediatric Ahmed valve tube, treated at a tertiary medical center between 2007 and 2018. Surgical success was defined as intraocular pressure between 6 and 22 mm Hg and reduced by at least 20% from its preoperative value, with or without intraocular pressure lowering medications, without additional surgical procedures and without vision loss.

Results: Fourteen eyes of 11 children were treated with the Ahmed tube extender during the study period. Mean age of all children was 5.7±4.7 years (range, 3 mo to 16 y). The most common type of glaucoma was congenital glaucoma (n=6, 42.9%). The mean age at the time of initial valve implant was 2.39±3.89 years and the mean duration from initial insertion to the extension was 3.39±2.95 years. The mean follow-up was 72.8±43.3 months (range, 12 to 140 mo), with 85.7% followed for >2 years. The mean survival was 34.1±37.2 months after the extension. Three surgeries (21.4%) were primary failures, 8 patients (57.1%) failed during follow-up (mean, 40.6±44.4 mo after the extension; range, 1 to 125 mo), whereas 3 patients (21.4%) maintained the successful outcome until their last follow-up visit (mean, 37.7±24.1 mo; range, 12 to 70 mo).

Conclusions: The Ahmed valve extender can often save a retracted or obstructed tube. The procedure has limited complications and long-term efficacy in one third of the patients.