Hypotony after glaucoma drainage device surgery for refractory pediatric uveitic glaucoma

PURPOSE: To evaluate incidence, management, and outcomes of hypotony following glaucoma drainage device (GDD) implantation in children with refractory pediatric uveitic glaucoma (PUG). METHODS: The medical records of consecutive PUG cases undergoing GDD implantation at a tertiary center from 2005 to 2024 were reviewed retrospectively. Hypotony was defined as intraocular pressure (IOP) of ≤5 mm Hg. Early hypotony was defined within the first 2 postoperative weeks and delayed hypotony between 4 and 6 weeks. Descriptive outcomes were reported per eye (n = 13), and statistical analyses were restricted to one eye per patient (n = 10) to maintain independence. RESULTS: Thirteen eyes of 10 children (mean age, 12.4 ± 3.4 years) underwent GDD implantation (8 valved, 5 nonvalved), with a mean follow-up of 27.2 ± 13.8 months. Hypotony occurred in 11 of 13 eyes (84.6%), including early hypotony in 8 of 13 eyes (mean duration, 32.1 ± 54.5 days; 6 required anterior chamber reformation) and delayed hypotony in 3 of 13 eyes (mean duration, 510.3 ± 488.9 days). Two of 13 eyes did not develop hypotony; both had preoperative IOP >40 mm Hg and were treated with valved devices. Two of 13 eyes developed late recurrence after initial resolution. Most episodes resolved without vision loss; however, 2 of 13 eyes developed vision-threatening complications. CONCLUSIONS: Hypotony after GDD implantation in PUG was frequent but often transient and compatible with stable visual outcomes. No significant associations were found between hypotony and type of GDD. Given the limited sample size and descriptive nature, further studies are needed. Careful monitoring remains essential, because hypotony may occur at different time points.