Advances in retinal prosthesis systems

Abstract

Retinal prosthesis systems have undergone significant advances in the past quarter century, resulting in the development of several different novel surgical and engineering approaches. Encouraging results have demonstrated partial visual restoration, with improvement in both coarse objective function and performance of everyday tasks. To date, four systems have received marketing approval for use in Europe or the United States, with numerous others undergoing preclinical and clinical evaluation, reflecting the established safety profile of these devices for chronic implantation. This progress represents the first notion that the field of visual restorative medicine could offer blind patients a hope of real and measurable benefit. However, there are numerous complex engineering and biophysical obstacles still to be overcome, to reconcile the gap that remains between artificial and natural vision. Current developments in the form of enhanced image processing algorithms and data transfer approaches, combined with emerging nanofabrication and conductive polymerization techniques, herald an exciting and innovative future for retinal prosthetics. This review provides an update of retinal prosthetic systems currently undergoing development and clinical trials while also addressing future challenges in the field, such as the assessment of functional outcomes in ultra-low vision and strategies for tackling existing hardware and software constraints.

Graphene Oxide–Based Nanomaterials: An Insight into Retinal Prosthesis

“…The technology of retinal prosthesis has developed gradually, allowing chip implants to electrically stimulate normal neurons to transmit signals. However, many problems still exist, including problems with the design of optical wireless transmission channels, signal resolution processing, and solar cell miniaturization [28][29][30][31]. On the other hand, there is a lack of research on the self-repair and regeneration of RGCs on these chips under electrical stimulation [32].…”

In-Vivo Microsystems: A Review

“…Although this does not give a high-quality image, it does allow a blind person sufficient image quality to function and navigate around objects. This work has shown the feasibility of the approach, and work is continuing to improve the image quality [ 76 , 77 ], including increasing the area of the electrode array and increasing the density of electrodes [ 78 , 79 ]. Another approach is to implant arrays of the probe directly into the optical cortex at the back of the brain [ 80 ].…”

Morphologic and electrophysiologic findings of retinal degeneration after intravitreal sodium iodate injection following vitrectomy in canines

“…Recently, visual prosthetics was implanted in humans with retinitis pigmentosa (RP) and choroideremia, although there was still a limit to visual improvement and safety 4,5 . Although restoration of visual field and visual acuity, and improvement in activities of daily life could be obtained by the implantation of visual prosthetics in advanced stage of retinal disorders, resolution of visual signal was still low to distinguish objects 6,7 . Furthermore, the cost of visual prosthetics is very expensive 8 and surgery of visual prosthetics implantation is difficult and could cause complication such as retinal detachment and dislocation of device 7,9 .…”

“…Although restoration of visual field and visual acuity, and improvement in activities of daily life could be obtained by the implantation of visual prosthetics in advanced stage of retinal disorders, resolution of visual signal was still low to distinguish objects 6,7 . Furthermore, the cost of visual prosthetics is very expensive 8 and surgery of visual prosthetics implantation is difficult and could cause complication such as retinal detachment and dislocation of device 7,9 . RP is one of inherited retinal dystrophies and one of the causes of irreversible vision loss.…”