Artificial retina device with stimulating and ground return electrodes disposed on opposite sides of the neuroretina and method of attachment

Abstract

An artificial retinal device, implanted in the subretinal space of the eye in persons with certain types of retinal blindness, induces artificial vision by electrical stimulation of the remaining viable cells of the retina. The artificial retina device includes a stimulating electrode unit preferably placed in the subretinal space, and a tail-like extension housing a distant electrical return ground electrode unit that may be placed in the vitreous cavity. The stimulating electrode unit includes an array of electrode subunits. Each electrode subunit includes one or more microphotodiodes electrically connected, for example, in series to provide increased voltage and current to its microelectrode. The stimulating electrode unit and the ground return electrode of the ground return electrode unit are preferably disposed on opposite sides of the neuroretina to allow for efficient and high resolution transretinal electrical stimulation of the neuroretinal cells. Additional photodiodes may be incorporated into the circuitry of the artificial retina device to provide additional bias voltage and current to the microelectrode subunits of the stimulating electrode unit. In another preferred embodiment, the ground return electrode in the tail-like extension is disposed in the capsular bag of the eye, after lens nucleus and cortex removal, where it is electrically connected to an additional bias photodiode or photodiodes.