Iris Obstruction Following PRESERFLO™ Microshunt Implantation and Surgical Management

Abstract

The aim was to present a case of lumen obstruction after implantation of microshunt with subconjunctival drainage and subsequent management.Case Report: A 56-year-old male with primary open angle glaucoma underwent uneventful PRESERFLO MicroShunt (PMS) implantation in both eyes. Five months after surgery the patient presented with an intraocular pressure (IOP) of 26 mm Hg in the right eye because of iris obstruction. Results:The iris fibers were severed and removed surgically to free the lumen. Follow-up showed a normalized IOP of 10 mm Hg and a free lumen. Conclusion:Uncontrolled IOP because of iris obstruction following PMS was addressed by surgical removal of iris fibers at the lumen entrance without the need for tube repositioning.

Preserflo MicroShunt: Efficacy and Endothelial Cell Density

“…Four eyes (28.6%) required surgical revision. Bleb revision because of conjunctival scarring (n=2), intracameral viscoelastic for postoperative hypotony, and removal of iris fibers obstructing the shunt lumen (n=1 each) 3 . Two eyes (14%) needed postoperative subconjunctival injections of 5-fluorouracil injection for modulation of wound healing, 5 and 14 times, respectively.…”

“…1 Disease progression is avoided by lowering the intraocular pressure (IOP) with either medical therapy, laser treatment, or surgery. [1][2][3] In terms of adherence to topical medication, patient compliance is known to be often limited. 4 Trabeculectomy is a widely performed surgery and is currently the gold standard in uncontrolled, moderate to severe glaucoma.…”

“…A fin-like enlargement segment of 4.5 mm from the tip serves for intraskleral fixation. 3,6 One of the main safety concerns, associated with the new glaucoma implants, mainly regarding their use in the longterm, is the corneal endothelial cell loss (ECL). Although the pathomechanism leading to ECL with minimally invasive glaucoma surgery implants is not fully understood, one of the proposed mechanisms is mechanical damage resulting by the proximity of the device to the endothelium.…”

“…Glaucoma, a group of eye diseases defined by retinal ganglion cell death resulting in cupping of the optic nerve head and visual field loss, is still one of the most common causes of blindness worldwide 1 . Disease progression is avoided by lowering the intraocular pressure (IOP) with either medical therapy, laser treatment, or surgery 1–3 . In terms of adherence to topical medication, patient compliance is known to be often limited 4 …”

“…The Preserflo MicroShunt (formerly InnFocus MicroShunt) is an 8.5-mm long stent, with an outer diameter of 0.35 mm and an internal lumen of 0.07 mm (equate to 70 µm) of polystyrene-block-isobutylene-block-styrene. A fin-like enlargement segment of 4.5 mm from the tip serves for intraskleral fixation 3,6 …”