Devices

An epiretinal implant that sends camera-derived stimulation to a platinum electrode array tacked over the fovea. FDA humanitarian device approval in 2013; discontinued by its maker in 2019, leaving more than 350 users with an unsupported implant.

Device — Other

Argus II retinal prosthesis

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retinal prosthesis · epiretinal · visual prosthesis · Second Sight · FDA HDE · discontinued · human · dead end

Argus II retinal prosthesis

One-line verdict: The first retinal prosthesis to reach routine clinical use in the US, and a case study in what happens to implanted users when the company behind a device fails.

Quick tags: Stimulation · Retina · Human · FDA HDE decision: 13 February 2013

Overview

What it is: A visual prosthesis for people with severe to profound retinitis pigmentosa and bare or no light perception in both eyes. The FDA labeling states it provides electrical stimulation of the retina to induce visual perception.

How it works: Glasses carry a miniature video camera and radio-frequency coils. A battery-powered video processing unit turns the video into stimulation data, which the glasses send with power to the implant by telemetry.

What is implanted: An electronics case and coil, held around the eyeball by a scleral band, and an electrode array tacked onto the retina. The array has 55 enabled platinum electrodes on a polymer cable and is secured over the fovea with a spring retinal tack.

What happened: IEEE Spectrum reports that Second Sight discontinued the implant in 2019 and nearly went out of business in 2020, and that more than 350 people with its implants were left with technology that is obsolete and unsupported.

Spec Card Grid

Identity

  • Regulatory: FDA humanitarian device exemption H110002, received 4 May 2011, decision 13 February 2013
  • Original maker: Second Sight Medical Products; the FDA record now lists Cortigent, Inc. as applicant

Architecture

  • Electrodes: 55 enabled, platinum, on a polymer cable
  • Placement: epiretinal, over the fovea, held by a retinal tack
  • Implant body: electronics case and coil on the eye, scleral band equivalent to a 240 band
  • External: camera glasses with RF coils, video processing unit worn in a pouch

Evidence and limits

  • Not covered here: implant dimensions and electrode diameter, which are in the FDA labeling figures; no 3D model yet
  • Approval note: the label says the device’s effectiveness for this use has not been demonstrated, as is standard for a humanitarian device

References