A woman in her 50s with advanced primary open-angle glaucoma presented 1 year postinsertion of an ab interno gelatin microstent (Xen; Allergan) with mitomycin C (MMC).1,2 On examination, her intraocular pressure (IOP) was 21 mm Hg while taking 3 glaucoma medications. Her microstent was patent in the anterior chamber. Her bleb was flat and fibrosed (Figure, A). After obtaining consent, needling with MMC and an ophthalmic viscosurgical device was initiated. Under topical anesthetic, 0.2 mL of 0.4-mg/mL MMC was injected superotemporally in the subconjunctival space and milked over the implant. Twenty minutes later, the subconjunctival space was entered superotemporally with a bent 27-gauge needle. Scar tissue was released above and below the implant and the sharp edge of the needle was rotated perpendicular to the stent to amputate its distal end. A ProVisc ophthalmic viscosurgical device was instilled around the stent and throughout the bleb. Her IOP was 8 mm Hg with a large diffuse bleb at 1 hour (Figure, B) and 14 mm Hg 3 weeks postneedling.
Szigiato A, Schlenker M, Ahmed IIK. Bleb Morphology After Needling With Viscoelastic of an Ab Interno Microstent Assessed by Optical Coherence Tomography. JAMA Ophthalmol. 2017;135(1):e164668. doi:10.1001/jamaophthalmol.2016.4668