Ahmed to Baerveldt glaucoma drainage device exchange in pediatric patients

Background: There is no consensus and few reports as to the surgical management of encapsulated Ahmed glaucoma drainage devices (GDD) which no longer control intraocular pressure (IOP), especially within the pediatric population. The purpose of this study was to report outcomes of exchanging the Ahmed GDD for a Baerveldt GDD in children with refractory glaucoma.

Methods: Retrospective review of children (< 18yrs) who underwent removal of Ahmed FP7 and placement of Baerveldt 350 (2016-2021) with ≥ 3-month follow-up. Surgical success was defined as IOP 5-20 mmHg without additional IOP-lowering surgeries or visually devastating complications. Outcomes included change in best-corrected visual acuity (BCVA), intraocular pressure (IOP), and number of glaucoma medications.

Results: Twelve eyes of 10 patients underwent superotemporal Ahmed FP7 to Baerveldt 350 GDD exchange at 8.8 ± 3.6 years. Time to Ahmed failure was 2.7 ± 1.9 years with 1-, 3-, and 5-year survival rates of 83% with a 95% CI[48,95], 33% with a 95% CI[10, 59], and 8% with a 95% CI[0, 30]. At final follow-up (2.5 ± 1.8 years), success rate for Baerveldt 350 GDDs was 75% (9 of 12 eyes) with 1 and 3-yr survival rates of 100% and 71% with 95% CI[25,92], respectively. IOP (24.1 ± 2.9 vs. 14.9 ± 3.1 mmHg) and number of glaucoma medications (3.7 ± 0.7 vs. 2.7 ± 1.1) were significantly decreased (p < 0.004). BCVA remained stable. Two eyes required cycloablation and 1 eye developed a retinal detachment.

Conclusions: Ahmed removal with Baerveldt placement can improve IOP control with fewer medications in cases of refractory pediatric glaucoma. However, more eyes with greater follow-up are required to determine long-term outcomes.