Artificial vision with wirelessly powered subretinal electronic implant alpha-IMS

TLDR

The study seeks to replace photoreceptor functions in patients blind from untreatable hereditary retinal degenerations. A 9 mm² microelectronic neuroprosthesis with 1500 microphotodiode‑amplifier‑electrode elements, powered transdermally, was subretinally implanted in nine patients, with performance tested against power‑off controls. In nine patients, the implant restored light perception (8/9), localization (7/9), motion detection (5/9), grating acuity up to 3.3 cpd, and limited visual acuity (20/546 in 2/9), improved object discrimination, enabled spontaneous letter reading in three subjects, and produced daily‑life visual perceptions in five subjects, demonstrating useful visual function restoration.

Abstract

This study aims at substituting the essential functions of photoreceptors in patients who are blind owing to untreatable forms of hereditary retinal degenerations. A microelectronic neuroprosthetic device, powered via transdermal inductive transmission, carrying 1500 independent microphotodiode-amplifier-electrode elements on a 9 mm(2) chip, was subretinally implanted in nine blind patients. Light perception (8/9), light localization (7/9), motion detection (5/9, angular speed up to 35 deg s(-1)), grating acuity measurement (6/9, up to 3.3 cycles per degree) and visual acuity measurement with Landolt C-rings (2/9) up to Snellen visual acuity of 20/546 (corresponding to decimal 0.037° or corresponding to 1.43 logMAR (minimum angle of resolution)) were restored via the subretinal implant. Additionally, the identification, localization and discrimination of objects improved significantly (n = 8; p < 0.05 for each subtest) in repeated tests over a nine-month period. Three subjects were able to read letters spontaneously and one subject was able to read letters after training in an alternative-force choice test. Five subjects reported implant-mediated visual perceptions in daily life within a field of 15° of visual angle. Control tests were performed each time with the implant's power source switched off. These data show that subretinal implants can restore visual functions that are useful for daily life.