Explantation of the CyPass implant in acase series of patients with corneal decompensation

Abstract

In microinvasive glaucoma surgery (MIGS) the CyPass microstent (Alcon Inc.) was implanted in the suprachoroidal space to increase the uveoscleral outflow, thereby lowering the intraocular pressure. Due to the excessive loss of corneal endothelial cells, the implant was withdrawn from the global market in August 2018. Aloss of corneal endothelial cells was observed in 6patients (8eyes in total) with early to moderate primary open-angle glaucoma 3years after CyPass implantation. One eye developed abullous keratopathy. In all patients an implant migration in the anterior chamber compared to the original postoperative position was detected, with more than one ring of the CyPass implant being visible in the anterior chamber. In all eight cases the CyPass implant was removed. The local therapy with cortisone eye drops in combination with a5% sodium chloride solution did not improve chronic corneal edema in one patient. Therefore, aDescemet membrane endothelial keratoplasty (DMEK) was performed with postoperative improvement of visual acuity. In patients with more than one visible ring of the CyPass implant in the anterior chamber and subsequent localized loss of corneal endothelial cells, CyPass trimming or removal is recommended to avoid the progression of generalized corneal endothelial cell reduction and the onset of refractory, chronic corneal edema.