Overview of the boston retinal prosthesis: Challenges and opportunities to restore useful vision to the blind

Abstract

A small, hermetic, wirelessly-controlled retinal prosthesis was developed for pre-clinical studies in Yucatan mini-pigs. The device was implanted on the outside of the eye in the orbit, and it received both power and data wirelessly from external sources. The prosthesis drove a sub-retinal thin-film array of sputtered iridium oxide stimulating electrodes. The implanted device included a hermetic titanium case containing the 16-channel stimulator chip and discrete circuit components. Feedthroughs in the hermetic case connected the chip to secondary power- and data-receiving coils, which coupled to corresponding external power and data coils driven by a power amplifier. Power was delivered by a 500 KHz carrier, and data were delivered by frequency shift keying. Stimulation pulse strength, duration and frequency were programmed wirelessly from an external computer system. Through an 'outbound' telemetry channel, electrode impedances were monitored by an on-board analog to digital converter that sampled the output voltage waveforms. The final assembly was tested in vitro in physiological saline and in vivo in two mini-pigs for up to three months by measuring stimulus artifacts generated by the implant's current drivers.

Improvement in vision: a new goal for treatment of hereditary retinal degenerations

“…For example, the development of a retinal prosthesis has a long history and there have been recent clinical trials; and further advances are expected. With evidence of extremely impaired vision, little or no measurable photoreceptors by OCT and presence of inner retinal laminae, this becomes one option 65 , 66 , 67 , 68 , 69 . Another evolving method uses optogenetics to transform remaining inner retinal cells into light sensors [70] .…”

Optogenetics, visual prosthesis and electrostimulation for retinal dystrophies

“…The field has progressed tremendously since then with a number of different investigators working on various types of visual prostheses [26,27]. Direct cortical stimulation remains an attractive strategy.…”

Therapeutische Ansätze bei Patienten mit Retinitis pigmentosa

“…Die längste Benutzungsdauer liegt bei einem Jahr [44]. Weitere Arbeitsgruppen führen präklinische Studien mit subretinalen Implantaten durch [45,46].…”