Are Subretinal Microphotodiodes Suitable as a Replacement For Degenerated Photoreceptors?

Subretinal electrical stimulation of the rabbit retina with acutely implanted electrode arrays

“…The novel transchoroidal approach has been highly successful in all experimental animals of this study in providing a way to the SRS aside of the classical, transvitreal access. Although many studies have been successfully performed by our consortium [13,14,26,32,33,34,44,45,46,47], many questions, such as the shape of the phosphenes elicited by the implants, their interpretation by the cortex, andtheir color will have to be answered by volunteers who can report on their perceptions.…”

“…It has been shown that these retinae tolerate a chronic implant without obvious damage [14,22,32]. In contrast to epiretinal implants, where the problem of permanent stability arises, experience in subretinal implantations has shown that the implant remains at the original position for years [14,22,32,33,43,44,45,46,47].…”

Perceptual Efficacy of Electrical Stimulation of Human Retina with a Microelectrode Array during Short-Term Surgical Trials

“…[1][2][3][4][5][6][7][8][9][10][11][12][13] A crucial milestone yet to be achieved is the demonstration that such devices improve the quality of life for blind patients. This psychophysical study is an initial feasibility assessment toward that milestone.…”

Investigation of thermal effects of infrared lasers on the rabbit retina: a study in the course of development of an active subretinal prosthesis

“…In this configuration, an external IR laser source irradiates a subretinally implanted IR receiver diode connected to the microphotodiode array (MPDA). The device consists of 1,500 light-sensitive microphotodiodes [36] and 1,500 microelectrodes made of titanium nitride [3,11,25,30,[43][44][45], which contact the retina from the subretinal space. Energy from the IR laser falls onto a separate, larger, IR-sensitive photodiode on the subretinal foil strip and is stored in a capacitor.…”