Conclusions: This series describes three cases of complications following XEN Gel Stent Implantation and Mitomycin C use that highlight the need for further studies on alternative anti-fibrotic agents for use during glaucoma filtration surgery.

Objective: We report the surgical management of three cases of postoperative bleb complications following XEN Gel stent implantation that are attributed to the use of mitomycin C (MMC).

Methods: Case 1: 76-year-old male with primary open angle glaucoma (POAG) underwent XEN Gel stent with MMC in the left eye. He presented with neurotrophic keratitis and thin conjunctiva with overlying epithelial defect and underlying avascular sclera consistent with scleromalacia four years following XEN surgery. He underwent scleral patch graft with conjunctival pedicle advancement flap and amniotic membrane transplant. He has progression of scleromalacia and consequently underwent five additional surgeries for scleral patch graft placement with cryopreserved amniotic membrane transplant in addition to conjunctival autograft from the contralateral eye.Case 2: 81-year-old male with POAG underwent XEN Gel stent placement with MMC in the right in superotemporal quadrant. Due to persistently elevated intraocular pressures, he subsequently underwent Baerveldt tube shunt implantation in the superotemporal quadrant in the right eye. He presented to our clinic 3 years later with Baerveldt tube erosion and surrounding scleral melt. He underwent tube shunt removal with scleral patch graft.Case 3: 59-year-old male with POAG in both eyes who underwent cataract extraction and XEN Gel placement with MMC in both eyes. Two years after XEN surgery he developed bilateral non-healing conjunctival epithelial defects over the blebs with minimal improvement on medical therapy. He required removal of the XEN gel stent with bleb revision and placement of inferonasal Baerveldt tube shunt in both eyes.

Conclusions: Xen Gel Stent implantation with mitomycin C was associated with scleral melt and blebitis, similar to reports following trabeculectomy. Adjunctive antimetabolite use should consider individualized patient risk profiles.