Study: Ahmed valve survival rate at 63% in patients younger than 2 years

Br J Ophthalmol. 2009;93(6):795-798.

Patients under the age of 2 years who received an Ahmed valve implantation had a cumulative valve survival rate of more than 60%, with postoperative tube malpositioning the most common postop complication, according to a study.

A retrospective, institutional case series examined 42 eyes of 36 patients. Of those, 28 eyes had primary congenital glaucoma, five eyes had aphakic glaucoma, and five eyes had Peters' anomaly. Sturge-Weber syndrome, aniridia, congenital rubella and steroid-induced glaucoma were each diagnosed in one eye. Three eyes in the study had not previously undergone surgery.

All patients had an Ahmed valve implanted before the age of 2 years, at a mean of 11.83 months, and patients were followed for 2 years.

"Cumulative probabilities of valve survival (IOP ≤ 22 mm Hg with or without medication) by Kaplan-Meier analysis were 73.8% and 63.3% at 12 months and 24 months, respectively," the study authors said.

The study also found that the most common significant postoperative complications were tube malpositioning that needed intervention in 26.2% of cases, endophthalmitis in 7.1% of cases and retinal detachment in 7.1% of cases.

In addition, 85.8% of eyes had to continue glaucoma medications to reduce IOP to an adequate level, the study authors said.