Purpose:
To design and test a new retina implant for the restoration of vision in patients with retinal degenerations that minimizes the necessary surgical trauma and implantation of foreign material into the eye.
Methods:
The permutative development process was including a logistic sequence of technical implant development, fabrication, and several steps of in vitro– and in vivo–experimental testing of devices. The latter included long–term (up to 10 months) observation of electrodes penetrating the sclera, choroid, and retina in rabbits and a series of prototype implantations with a variant number of electrodes in monkeys (n=5) with long–term observation (6 months).
Results:
The technical design process was resulting in a retina implant system as demonstrated in Fig. 1. The external unit includes a camera (CAM) integrated into a glass frame, the external electronic unit EEU (energy supply, image processor, encoder, transmitter) and a transmitting coil (t–coil). Implant components are: receiving coil (r–coil), internal electronic units (IEU) and stimulating electrodes. The latter electrodes penetrate the intact sclera, choroid and retina and represent the only intraocular part of the system. Results of experimental implantation of prototypes in rabbits and monkeys clearly demonstrate that perforating electrodes can easily be implanted without complications and are well tolerated in long term observation.
Conclusions:
Results of experimental implantation of a minimal invasive retina implant with penetrating stimulation electrodes clearly demonstrate that this approach seems to be a promising technical option for the restoration of orientation in patients with degenerative retinal diseases.
Keywords: retina • retinal degenerations: hereditary • vitreoretinal surgery