Ahmed Valve Tube Extension in Pediatric Glaucoma

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

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

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.

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).

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.