gms | German Medical Science

Retina implants designed for epi- or subretinal stimulation are setting completely new challenges concerning the surgical management (critical anatomical sites of implantation, complex high risk interventions) and long-term biocompatibility of relatively large intraocular objects. Problems to be solved are mechanical implant stabilization, foreign body reaction, retinal long-term survival and the induction of proliferative reactions. It is the aim of the minimal invasive retinal implant project (miRI) to overcome the obvious disadvantages of large scale intraocular implant deposition by designing a new retina implant system. It is the principle of this new design that all components of the implant are deposited externally to the sclera and only the stimulating electrodes are penetrating the eye via sclera and choroid. Obviously this concept is in conflict with the general assumption that multiple ab externo penetration of the choroid might be a harmful procedure and that implants penetrating the eye permanentely would cause undesired tissue reactions. To evaluate the feasibility and principle design of implants for direct stimulation of the retina by penetrating electrodes a set of in vitro- and in vivo experimental series including eyes of rabbits and monkeys were performed. Results so far show that miRI-type devices can safely implanted by a minimal surgical approach without the necessity to perform a vitrectomy or any other intraocular manipulation beside of the penetration of stimulation electrodes.

This lecture is available as video recording (Attachment 1 [Attach. 1]).