Ocular hypotony precipitated by Tube Trimming in a uveitic eye with Descemet Membrane Stripping Automated Endothelial Keratoplasty and prior tube revision

Abstract

Background To describe ocular hypotony precipitated by trimming of a glaucoma shunt tube in an eye with uveitic glaucoma, a failed Descemet Membrane Stripping Automated Endothelial Keratoplasty (DSAEK) and prior tube revisions.Case Presentation: A patient in her thirties with uveitic glaucoma of the right eye had endothelial decompensation of a DSAEK graft secondary to corneal endothelial touch from two previous glaucoma drainage implants. She underwent ab-interno tube trimming and subsequently developed postoperative hypotony with intraocular pressure (IOP) of 2 mm Hg. Intraoperative Trypan blue was effectively utilized to make the diagnosis of an over-filtering glaucoma drainage device, despite the presence of an intraluminal stent. Tube ligation was performed, and the IOP increased to 8 mmHg. IOP has remained stable at a 6-month follow-up review.Conclusions Glaucoma shunt tube trimming may be associated with development of ocular hypotony despite minimal manipulation or removal of the associated intraluminal stent in non-valved glaucoma drainage devices. Trypan blue may be considered as a useful diagnostic adjunct for determining the underlying cause of hypotony in such cases.