Transretinal electrical stimulation by an intrascleral multichannel electrode array in rabbit eyes

Abstract

Our technique for STS with an intrascleral microelectrode array is safe in rabbit eyes, and EEPs were elicited by current densities that did not induce tissue damage. These results suggest that STS via intrascleral multichannel electrodes is a feasible method for stimulating the retina.

Implantable CMOS biomedical devices

“…Based on this principle, a retinal prosthesis device stimulates retinal cells with a patterned electrical signal so that a blind patient may sense a patterned phosphene, or something like an image. According to the site at which the retinal stimulator is placed, the retinal prosthesis device is classified into three categories: epi-retinal stimulation [18][19][20][21], sub-retinal stimulation [22][23][24][25], and suprachoroidal transretinal stimulation (STS) [25,26], which has recently been developed. The stimulation site may be located not only in retinal cells, but also in the pathways to the brain, such as the optic nerves [27], which are the transmission lines of visual information, and, of course, in the visual cortex [28], which is the terminal of the visual information.…”

“…As mentioned previously, this method is classified into three types according to the stimulator implantation site: epi-retinal stimulation [18][19][20][21], sub-retinal stimulation [22][23][24], and STS [25,26]. Figure 6 illustrates these three types of retinal implantation.…”

Comparative Study of Sevoflurane and Isoflurane Anesthesia for the Long-term Safety Evaluation of Visual Prosthesis with Rabbits

“…(5) Injected anesthetics, such as ketamine/xylazine or pentobarbital, were used in the previous study. (7) These injected anesthetics caused difficulties in controlling the depth of anesthesia, and a high potential for death due to repeated anesthesia was noted. (8) In addition, VEPs were only recorded during a short period just before awakening, since they disappeared in deep anesthesia and their amplitudes varied with the depth of anesthesia; hence, VEP measurement under fixed conditions is difficult.…”

Rabbit Retinal Ganglion Cell Activation Thresholds in Response to Various Electrical Stimulation Waveforms using a Different Spatial Resolution Electrode Array

“…Phosphene perception has been reported clinically for these prosthetics [4]. Although implantation is easier in terms of surgery and there is less risk of retinal detachment, these prosthetics do not provide the same spatial resolution that can be achieved by other approaches, and they require higher threshold currents to stimulate the retina because of the relatively long distance between the retina and the sclera [5][6][7]. With subretinal implants, electrodes are placed between the photoreceptor layer and retinal pigment epithelium layer.…”