Cited by 229Neuroscience and Neural EngineeringRetinal Diseases and TreatmentsRetinal Development and Disorders

Photovoltaic Restoration of Central Vision in Atrophic Age-Related Macular Degeneration

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Palanker, Daniel, Le Mer, Yannick, Mohand-Said, Saddek, Muqit, Mahiul, Sahel, Jose A.·2020·Ophthalmology

Abstract

PURPOSE: Loss of photoreceptors in atrophic age-related macular degeneration results in severe visual impairment, although some peripheral vision is retained. To restore central vision without compromising the residual peripheral field, we developed a wireless photovoltaic retinal implant (PRIMA; Pixium Vision, Paris, France) in which pixels convert images projected from video glasses using near-infrared light into electric current to stimulate the nearby inner retinal neurons. DESIGN: We carried out a first-in-human clinical trial to test the safety and efficacy of the prosthesis in patients with geographic atrophy (ClinicalTrials.gov identifier, NCT03333954). PARTICIPANTS: Five patients with geographic atrophy zone of at least 3 optic disc diameters, no foveal light perception, and best-corrected visual acuity of 20/400 to 20/1000 in the worse-seeing study eye. METHODS: The 2-mm wide, 30-μm thick chip, containing 378 pixels (each 100 μm in diameter), was implanted subretinally in the area of atrophy (absolute scotoma). MAIN OUTCOME MEASURES: Anatomic outcomes were assessed with fundus photography and OCT for up to 12 months of follow-up. Prosthetic vision was assessed by mapping light perception, bar orientation, letter recognition, and Landolt C acuity. RESULTS: In all patients, the prosthesis was implanted successfully under the macula, although in 2 patients, it was implanted in unintended locations: within the choroid and off center by 2 mm. All 5 patients could perceive white-yellow prosthetic visual patterns with adjustable brightness in the previous scotomata. The 3 with optimal placement of the implant demonstrated prosthetic acuity of 20/460 to 20/550, and the patient with the off-center implant demonstrated 20/800 acuity. Residual natural acuity did not decrease after implantation in any patient. CONCLUSIONS: Implantation of the PRIMA did not decrease the residual natural acuity, and it restored visual sensitivity in the former scotoma in each of the 5 patients. In 3 patients with the proper placement of the chip, prosthetic visual acuity was only 10% to 30% less than the level expected from the pixel pitch (20/420). Therefore, the use of optical or electronic magnification in the glasses as well as smaller pixels in future implants may improve visual acuity even further.

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Crossref · 10.1016/j.ophtha.2020.02.024

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  • The PRIMA device achieved a visual resolution of approximately 1.2 pixels.

    “testing showed a good correlation between the number of stimulators and visual acuity, achieving a visual resolution of approximately 1.2 pixels.”
  • Comparison of visual acuity with the device switched ON and OFF showed improvement only for the PRIMA and Argus II devices.

    “By this metric, comparison of visual acuity with the device switched ON and OFF showed improvement only for the PRIMA35 and Argus II9 devices.”
  • Subretinal devices have a size providing a maximum restored visual angle of about 10°, suitable only for applications where a small part of the visual field is lost, such as AMD.

    “Devices have a size providing a maximum restored visual angle of about 10 • , suitable only for applications where a small part of the visual field is lost, such as AMD [48,49].”
  • The highest visual acuities reported to date, measured with the Landolt-C test, were 20/460 with the subretinal implant PRIMA (in AMD patients) and 20/546 with the subretinal implant Alpha-AMS (in RP patients).

    “The highest visual acuities reported to date, as measured with the Landolt-C test, were 20/460 with the subretinal implant PRIMA (in AMD patients) [48] and 20/546 with the subretinal implant Alpha-AMS (in RP patients) [133].”
  • The ideal case of avoiding fading is rarely reached and has only been reported for the PRIMA device and some patients with Alpha IMS, most likely with preserved eye movements.

    “However, this ideal case is rarely reached and has only been reported for the PRIMA device [48] and some patients with Alpha IMS, most likely with preserved eye movements [154].”

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Research works printed but not linked: 2

  1. [23]Mathieson K, Loudin J, Goetz G, Photovoltaic retinal prosthesis with high pixel density. Nature Photonics 2012; 6: 391– 7. 23049619 PMC3462820
  2. [25]Ho E, Smith R, Goetz G, Spatiotemporal characteristics of retinal response to network-mediated photovoltaic stimulation. J Neurophysiol 2018; 119: 389– 400. 29046428 PMC5867391

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Authors
Palanker, D., Le Mer, Y., Mohand-Said, S., Muqit, M., & Sahel, J. A.
Affiliations
  • Stanford University (US)
  • Moorfields Eye Hospital NHS Foundation Trust (GB)
Corresponding author
Palanker, Daniel
Venue
Ophthalmology
Publisher
Elsevier BV
Published
2020-08
Volume
127
Issue
8
Pages
1097-1104
ISSN
0161-6420 (ISSN-L)
OpenAlex
W3006860701
Cited by
227
References
36
Citations by year
2026: 31 · 2025: 29 · 2024: 26 · 2023: 37 · 2022: 37 · 2021: 44 · 2020: 22 · 2019: 1
FWCI
16.03
Type
journal article
Language
en
Open access
Locations
  • Ophthalmology (publishedVersion, cc-by)
  • PubMed (publishedVersion)
  • PubMed Central (acceptedVersion)
  • UCL Discovery (University College London) (submittedVersion)
Funders
National Institutes of Health
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neural Engineering
  • Health Sciences › Medicine › Ophthalmology › Retinal Diseases and Treatments
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Retinal Development and Disorders
Keywords
dry age-related macular degeneration, geographic atrophy, PRIMA, subretinal implantation, scotoma, photoreceptor loss, implant safety and efficacy, pixel pitch
MeSH terms
Electrodes, Implanted, Feasibility Studies, Female, Humans, Macula Lutea, Macular Degeneration, Male, Middle Aged, Visual Perception, Recovery of Function, Tomography, Optical Coherence, Visual Prosthesis

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