Vitreous Hemorrhage Following Combined Cataract And Istent Surgery : A Case Report.

To report a complication of iStent trabecular bypass stent implantation in a patient undergoing combined cataract and microinvasive glaucoma surgery.

iStent inject^® is designed to increase outflow by directly bypassing the inner wall of Schlemm's canal. The stents are placed ab internally through the trabecular meshwork into Schlemm’s Canal. Implantation is completed either following phacoemulsification (in combined-cataract cases) or as a standalone procedure. iStent inject^®  is intended to reduce intraocular pressure in patients diagnosed with primary open-angle glaucoma, pseudo-exfoliative glaucoma, or pigmentary glaucoma.

A 72-year-old male with a history of glaucoma under fixed combination of bimatoprost-timolol and oral anticoagulation consulted for decreased vision (visual acuity and visual field).His intra-ocular pressure (IOP) was 24 mm Hg in right eye (OD) and 23 mm Hg in left eye (OS) with an altered ocular surface.The decision was made to perform combined cataract extraction with iStent implantation left eye then right eye. On postoperative day 1 (OS) patient presented with 15 mmHg IOP, stage 2 hyphema and grade 3 intravitreal hemorrhage. Hyphema resolved with conservative medical management. The vitreous hemorrhage persisted for two months and required vitrectomy. Appropriate placement was confirmed by gonioscopy. Six months after vitrectomy the patient has ,had complete resolution of symptoms without recurrence of hyphema and vitreous hemorrhage. (IOP) was 14 mm Hg in right eye (OD) and 16 mm Hg in left eye (OS). Possible mechanism that we considered was spill-over hemorrhage from the anterior chamber hyphema. Even if the preoperative examination did not find pseudoexfoliation, this has been associated with zonular instability,which would allow for communication between the anterior and posterior segments.

This case illustrates a complication of iStent placement. Nothing suggested after the preoperative examination the occurrence of an intravitreal hemorrhage. We describe the evolution of the symptoms, diagnosis and treatment of this patient by putting forward physiopathological hypotheses that may explain the origin of the vitreous hemorrhage. It is generally accepted that intraocular bleeding after phacoemulsification cataract surgery does not justify the withdrawal of anticoagulant agents, there is no clear guidance for combined cataract and MIGS.