Purpose: To compare the outcome of the intraocular pressure (IOP) of Ahmed glaucoma valve (AGV) revision to visco-trabeculotomy (VT) in children's eyes with failed AGV.
Patients and methods: A prospective randomized study conducted on 41 children (41 eyes) with uncontrolled glaucoma with an AGV presenting to the pediatric ophthalmology clinic of Mansoura Ophthalmic Center between 2011 and 2016. Study eyes were randomized to AGV revision or VT. Success (true and qualified) (IOP<21 mm Hg without any sight-threatening complications) was studied at the end of 12-month follow-up. Operative complications were noted. The primary outcome was the IOP before and after the study intervention.
Results: The mean±SD age of the study children was 7.9±2.6 and 7.7±2.6 years in the AGV revision (19 eyes) and VT groups (22 eyes), respectively (P=0.654). The most common glaucoma type was primary congenital glaucoma in both groups. The mean±SD of the duration between the last glaucoma procedure and the current study intervention was 24.9±4.8 and 25.2±5.8 months in the AGV revision and VT groups, respectively. The mean±SD preoperative IOP and at 12-month follow-up was 32.1±3.2 and 23.2±3.5 mm Hg in the AGV revision group and was 33.3±2.2 and 20.0±3.5 mm Hg in the VT group. The total success rates at 12 months were 31.6% and 63.7% in the AGV revision and VT groups, respectively.
Conclusions: Both VT and AGV revision are reasonably successful and safe interventions for refractory childhood glaucoma after the failure of an AGV. VT is significantly better than AGV revision, resulting in higher success rates and a decrease in IOP-lowering medication use.