|Programm||"Degeneration und Regeneration– Grundlagen, Diagnostik und Therapie"|
New Developments in Electronic Visual Prosthesis
Worldwide, four main strategies are pursued in order to partially restore vision that has been impaired due to retinal degeneration. Two of these strategies are directly targeting the retina by stimulating either the inner retina via the sub-retinal implantation of an active micro-photodiode array, or the ganglion cells via the epi-retinal implantation of a multi-electrode array. Another strategy is targeting the optic nerve through an implant enveloping the fibres, and the last strategy is directly targeting the primary visual cortex, implanting a subcranial, cortical surface multi-electrode array. Depending on the targeting site of the implant, different, more or less sophisticated encoding of the stimulus signals is achieved through electronic devices. With the exception of the sub-retinal approach which generates a direct input signal, the input signal for these devices is delivered through video chips incorporated into glasses. All four strategies share the problems of biocompatibility, durability, stable fixation of the prosthesis and at the same time ease of its potential removal. Furthermore, initial clinical tests within the USA have revealed the critical importance of neuropsychological care during the training phase. Since 1995, the developing of retinal prosthesis in Germany receives financial support from the federal government which has also set up a board of experts supervising the different initiatives.