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Review
. 2014 Jan;11(1):23-30.
doi: 10.1586/17434440.2014.862494. Epub 2013 Nov 22.

The functional performance of the Argus II retinal prosthesis

H Christiaan Stronks  1 , Gislin Dagnelie
Affiliations
Review

The functional performance of the Argus II retinal prosthesis

H Christiaan Stronks et al. Expert Rev Med Devices. 2014 Jan.

Abstract

Visual prostheses are devices to treat profound vision loss by stimulating nerve cells anywhere along the visual pathway, typically with electrical pulses. The Argus II implant, developed by Second Sight Medical Products (SSMP, Sylmar, CA, USA), targets the retina and features 60 electrodes that electrically stimulate the surviving retinal neurons. Of the approximately 20 research groups that are actively developing visual prostheses, SSMP has the longest track record. The Argus II was the first visual prosthesis to become commercially available: it received the European conformity mark in 2011 and FDA approval was granted in early 2013 for humanitarian use in the USA. Meanwhile, the Argus II safety/benefit study has been extended for research purposes, and is still ongoing. In this review, we will discuss the performance of the Argus II in restoring sight to the blind, and we will shed light on its expected developments in the coming years.

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Figures

Fig. 1
Fig. 1
Schematic organization of the eye and the retina. (A) Schematic cross section through the human eye with an enlargement of the retina. (B) Different implant locations in the eye: Epiretinal (Argus II, EPIRET), subretinal (alpha-IMS), and suprachoroidal (Bionic Vision Australia). The epiretinal location favors ganglion cell stimulation, while subretinal implants favor the activation of bipolar cells. Reproduced with permission from Webvision [61]. Copyright © 2013 Webvision.
Fig. 2
Fig. 2
External and implanted parts of the Argus II retinal prosthesis. (A) Photograph of the external parts of the Argus II prosthesis system (Second Sight Medical Products, Inc., Sylmar, CA) showing the glasses with the camera and external radiofrequency (RF) coil, and video-processing unit (VPU) with rechargeable battery. B) Illustration of the implanted parts of the Argus II prosthesis system, including the 6 × 10 electrode array, electronics case, and subconjunctival RF coil. The RF link established between the external and implanted coil provides the implant with the necessary information for stimulation, as well as the necessary electrical energy. C) Fundus photograph of an implanted Argus II array in the macular region. The array is secured to the retina with a retinal tack. The handle is used by the retinal surgeon to manipulate the array during surgery [7, 50, 62]. Pictures reproduced with permission from Second Sight Medical Products, Inc., Sylmar, CA.
Fig. 3
Fig. 3
Schematic representation of a part of the Argus II electrode array to show the theoretical grating visual acuity (VA) limit of the Argus II device. The electrodes have a diameter of 200 μm and center-to-center electrode spacing is 575 μm. The finest grating that can be represented on an electrode grid with these dimensions has a cycle of 1150 μm on the retina. Assuming that 1° covers 288 μm retinal surface [63], the maximum VA achievable with the Argus II is 4°. Note that the Argus II array has 6 × 10 electrodes and the entire electrode grid spans approximately 20° of the field of view along the diagonal.
See this image and copyright information in PMC

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References

    1. Humayun MS, De Juan E, Jr, Dagnelie G, et al. Visual perception elicited by electrical stimulation of retina in blind humans. Arch Ophthalmol. 1996;114(1):40–46. - PubMed
    1. Humayun MS, Weiland JD, Fujii GY, et al. Visual perception in a blind subject with a chronic microelectronic retinal prosthesis. Vision Res. 2003;43(24):2573–2581. - PubMed
    1. Yanai D, Weiland JD, Mahadevappa M, et al. Visual performance using a retinal prosthesis in three subjects with retinitis pigmentosa. Am J Ophthalmol. 2007;143(5):820–827. - PubMed
    1. De Balthasar C, Patel S, Roy A, et al. Factors affecting perceptual thresholds in epiretinal prostheses. Invest Ophthalmol Vis Sci. 2008;49(6):2303–2314. - PMC - PubMed
    1. Caspi A, Dorn JD, Mcclure KH, et al. Feasibility study of a retinal prosthesis: spatial vision with a 16-electrode implant. Arch Ophthalmol. 2009;127(4):398–401. - PubMed
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