Is the Xen® Gel Stent really minimally invasive?

To describe a case of severe Streptococcus pneumoniae endophthalmitis in a patient with a cystic, avascular filtering bleb who had been implanted with a Xen® Gel Stent 21 months previously.

A 64-year-old woman with open-angle glaucoma developed severe endophthalmitis 21 months after Xen® Gel Stent implantation. On presentation, visual acuity was limited to light perception. Examination revealed a 100% hypopyon, blebitis and an exposed stent, along with orbital cellulitis. Immediate explantation of the exposed Xen® was performed, and intravitreal antibiotics were administered. S. pneumoniae was isolated from an anterior chamber paracentesis. Based on the antibiogram, the patient was treated with topical fortified piperacillin, gentamicin and vancomycin along with appropriate systemic antibiotics (intravenous imipenem and oral levofloxacin). After 3 days of antibiotics, she received a daily intravenous bolus of methylprednisolone at a dose of 1 mg/kg/day for three days. Despite these measures, the patient's condition declined, with purulent melting of the globe requiring evisceration.

As for other filtering surgeries, blebitis and severe endophthalmitis can occur after Xen® Gel Stent implantation. Patients with thin conjunctiva and/or cystic blebs over the stent should be followed particularly closely.