gms | German Medical Science

Background: To demonstrate feasibility and safety of implantation and removal surgery of completely wireless EPIRET3 retinal implants in six blind subjects.

Methods: The EPIRET3 device was implanted in six blind subjects suffering from Retinitis Pigmentosa enrolled in a prospective exploratory clinical trial. Surgery included vitrectomy, removal of the lens and implantation via a corneal incision. The following 28 days repetitive clinical examinations included visual acuity, slit lamp examination, intraocular pressure, funduscopy and fluorescein angiography. According to the schedule of the clinical trial explantation was performed four weeks after implantation.

Results: Implantation was successful in all patients. While the anterior part was fixed via transscleral sutures, the stimulating foil was placed onto the posterior pole using retinal tacks. The Implant was well tolerated in five eyes showing moderate postoperative inflammation while the position of the implant remained stable until surgical removal. In one case a severe non-bacterial inflammation with sterile hypopyon temporally appeared in the anterior chamber and required surgical intervention to gain complete recovery. Explantation of the device was successful in all cases. In one eye removal of the retinal tack during explantation surgery was necessary because of gliosis formation on the retinal surface. This maneuver caused a localized retinal defect which led to the decision to use a silicone oil endotamponade at the end of surgery.

Conclusions: Implantation surgery and removal of the device were successfully performed in all cases. In spite of the appearance of tolerable adverse events in two patients the general feasibility and safety of the surgical procedures could be proved.