Tube Length Adjustment and Tube Trimming Technique in Refractory Glaucoma

Abstract

Secondary glaucoma may develop after vitreoretinal surgery as it is a known risk factor for its development. When the risk factors are more than one, for instance along with neovascular glaucoma (NVG), the secondary glaucoma may become recalcitrant and very difficult to manage. Surgical intervention is often warranted to control intraocular pressure (IOP) and prevent progressive glaucomatous damage in patients with refractory glaucoma, and glaucoma drainage implant may be preferred as the primary choice. We describe a patient who develop secondary glaucoma after vitrectomy and silicone oil (SO) injection due to unresolved vitreous hemorrhage in proliferative diabetic retinopathy (PDR) and subsequent NVG. Baerveldt glaucoma implant (BGI) was carried out and placed in the superotemporal quadrant with longer anterior chamber tube placement to prevent escape of SO through the tube. Qualified success was achieved with additional one fixed-drug combination (FDC). However, 3 years later, the tube was blocked by the iris tissue at the inferior edge of the pupil. Tube trimming was performed efficiently using a simple technique. The distal end of the tube was pulled out of the anterior chamber through a paracentesis just next to the tube entrance and trimmed to the appropriate length. More than a year after the surgery, IOP was still well controlled with the same FDC. Unfortunately, the visual acuity could not be recovered due to advanced PDR.

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

“…The ab externo approach to tube trimming involves conjunctival dissection, removal of the tube from the anterior chamber, tube shortening, and subsequent reinsertion and suturing. In contrast, ab interno approaches have been more recently described as a quicker and simpler surgery without the need for conjunctival dissection, potentially reducing conjunctival scarring and subsequent tube failure (3)(4)(5).…”

Glaucoma Valve Repositioning During DSAEK

“…The straight needle was then removed allowing the tube end to return to its position posterior to The presence of a glaucoma shunt tube in the anterior chamber can present challenges during DSAEK surgery, especially when unfolding and centering the lenticule. Although various techniques have been described for AGV tube end trimming, [6][7][8] it was unsuitable in this case due to the position of the tube and shallow anterior chamber. The technique we describe is controlled and effective to enable positioning of the AGV and centration of the graft without undue manipulation of the graft endothelial surface.…”