Downsizing a Baerveldt Glaucoma Implant for the Management of Persistent Postoperative Hypotony: A Case Series

Purpose:The purpose of this study was to describe a surgical technique for treating persistent hypotony after Baerveldt glaucoma implant (BGI) surgery.Materials and Methods:The medical records of 10 patients with persistent postoperative hypotony who underwent truncation of one or both wings of a previously placed BGI, combined with external ligation of the tube using a polypropylene suture, were retrospectively reviewed.Results:All 10 eyes that underwent BGI truncation and placement of a single, external, nonabsorbable (polypropylene) tube ligature exhibited resolution of hypotony within 24 hours and resolution of choroidal effusions within the first 2 postoperative weeks. The median time interval between primary BGI surgery and truncation was 5 months (range, 1.5 mo to 8 y). Median postrevision follow-up time was 12 months (range, 5 mo to 16.2 y). The mean preoperative intraocular pressure (IOP) was 2.11.0 mm Hg, and the mean IOP rose to 29.213.9 mm Hg on postoperative day 1. Mean IOP at week 1, month 1, and month 3 was 20.510.4, 19.711.8, and 18.08.2 mm Hg, respectively, using an average of 1.41.4 glaucoma medications at postoperative month 3. Ligature release after BGI revision was performed in 9 (90%) of the 10 patients. The median time to ligature release was 1.5 months (range, 3 wk to 4 y). There was no recurrence of hypotony in any of these patients. At most recent follow-up, the mean IOP was 12.96.0 mm Hg on an average of 1.51.3 glaucoma medications. Five patients demonstrated improvement in visual acuity from their prerevision best-corrected visual acuity.Conclusions:Truncation of one or both wings of a BGI and complete closure of the tube with nonabsorbable, but releasable, suture ligature is an effective and safe method for reversing persistent postoperative hypotony while maintaining IOP control.