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Cited by 44Neuroscience and Neural EngineeringTactile and Sensory InteractionsPain Management and Treatment

Advances in visual prostheses: engineering and biological challenges

Open access
Borda, Eleonora, Ghezzi, Diego·2022·Progress in Biomedical Engineering
DOI 10.1088/2516-1091/ac812c
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Abstract

Vision is an extraordinary sense through which we can appreciate the beauty of the world we live in, gain invaluable knowledge and communicate with others using visual expression and arts. On the contrary, blindness is a threatening medical condition disrupting the life of affected people and their families. Therefore, restoring sight is one of the open challenges of our society. Today, the synergistic convergence of science and technology holds the potential to provide blind patients with artificial vision using visual prostheses: a type of implantable medical device able to reactivate visual neurons using electrical stimulation. Although clinical trials showed that vision restoration is still far away, significant technological advances make visual prostheses a valuable solution for blind patients. This review is not only a description of the state-of-the-art. Instead, it provides the reader with an update on recent developments, a critical discussion of the open challenges, and an overview of promising future directions.

AI snapshot

Written from the paper’s full text.

TL;DR

This review synthesizes engineering and biological challenges of visual prostheses across the retina, optic nerve, LGN, and V1, noting that retinal implants are the most clinically advanced but still provide vision substitution rather than full restoration. It highlights quantitative limits in visual field and resolution, electrode–tissue interface issues, image encoding, wireless power, biological variability, and market/regulatory lessons from first-generation devices.

Key findings

  • Visual prostheses are classified by target along the visual pathway: retina, optic nerve, LGN, and V1. Only retinal prostheses have reached clinical approval, and only for retinitis pigmentosa (RP): Argus® II, IRIS® II, and Alpha IMS/AMS; none remain on the market.
  • Best reported visual acuities were 20/460 with the subretinal PRIMA implant in AMD patients and 20/546 with the subretinal Alpha-AMS in RP patients. Grating acuities ranged from 20/1260 with the epiretinal Argus® II to 20/364 with the subretinal Alpha-AMS.
  • A visual angle of 30°–35° was identified as the minimal requirement for mobility and daily tasks under simulated prosthetic vision. POLYRETINA is described as a high-density wide-field epiretinal prosthesis with 10,498 photovoltaic pixels over approximately 43° (about 140 mm²).
  • Temporal limits include phosphene fading; flicker fusion (30 Hz or above) was achieved only for the PRIMA device in AMD patients. Market challenges include RP affecting about 1.5–2 million people, but only 12% having visual acuity worse than counting fingers and 0.5% having no light perception; Argus® II cost 115,000 EUR in Europe to 150,000 USD in the USA, with one patient estimating total device, surgery, and rehabilitation costs at 497,000 USD.

Methods

  • Narrative review; the paper states that no new data were created or analysed.
  • Synthesizes literature on the visual system, device categories by anatomical target, clinical and preclinical trials, and quantitative, technological, biological, and market/regulatory challenges.
  • No systematic search strategy, inclusion criteria, or quantitative meta-analysis is described.

Limitations

  • The paper does not include a formal limitations section; as a narrative review, it lacks systematic search/selection criteria and quantitative synthesis (evident from the text).
  • The authors state key knowledge gaps: insufficient understanding of the neural visual code in blind individuals, unclear predictiveness of animal models, and variable retinal remodelling and plasticity across patients.
  • Evident from the text: many cited outcomes come from heterogeneous, device-specific clinical and preclinical reports, and first-generation approved retinal prostheses were discontinued, limiting long-term generalizability and patient support.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1088/2516-1091/ac812c

Cites

223 of 223 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Claims the paper makes

0 of 185 cited sources checked · 0 supported · 0 flagged

  • Premisereasoning

    Retinal prostheses can offer artificial vision only to blind patients with outer retinal diseases causing progressive loss of retinal photoreceptors.

    “Therefore, they can offer artificial vision only to blind patients with outer retinal diseases, causing the progressive loss of retinal photoreceptors.”
    Quote in the paperNot a substantial claim
  • Premisenone given

    Visual prostheses bypass the damaged segment of the visual path and electrically stimulate downstream surviving visual neurons to induce artificial vision.

    “Visual prostheses bypass the damaged segment of the visual path and electrically stimulate the downstream surviving visual neurons to induce artificial vision.”
    Quote in the paperSubstantial claim
  • Premisecitation

    The device position and the characteristics of the electrical pulses determine which cell population is predominantly activated.

    “The device position (epiretinal, subretinal or suprachoroidal) and the characteristics of the electrical pulses (such as duration and waveform) determine which cell population is predominantly activated [28,29].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [28] Boinagrov, 2014, Selectivity of direct and network-mediated stimulation of the retinal ganglion cells with epi-, sub- and intraretinal electrodes, J. Neural Eng. source

      Not checked in the free run.

    • cites [29] Chenais, 2019, Capacitive-like photovoltaic epiretinal stimulation enhances and narrows the network-mediated activity of retinal ganglion cells by recruiting the lateral inhibitory network, J. Neural Eng. source

      Not checked in the free run.

  • Interpretationreasoning

    Visual prostheses represent a viable therapeutic solution to improve mobility and daily-life activities in blind individuals.

    “With multiple devices granted Food and Drug Administration (FDA) approval and CE mark for clinical use and many others in preclinical and clinical validation, visual prostheses represent a viable therapeutic solution to improve mobility and daily-life activities in blind individuals.”
    Quote in the paperSubstantial claim
  • Premisecitation

    Network-mediated stimulation is also possible from an epiretinal device if long (more than 8 ms) or non-rectangular pulses are used.

    “However, the network-mediated stimulation is also possible from an epiretinal device if long (more than 8 ms) or non-rectangular pulses are used [29][30][31].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [29][30][31]

      Not checked in the free run.

  • Classified as probably not a substantial claim. 25
  • May combine two claims. 52

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    The LGN in the thalamus has potential for individuals with either retinal or optic nerve pathologies.

    “The LGN in the thalamus has potential for individuals with either retinal or optic nerve pathologies.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Prospective approaches such as gene and cell therapies or optogenetics only focus on the retina and are ineffective when pathologies irremediably damage the retina or the optic nerve.

    “Prospective approaches, like gene and cell therapies or optogenetics, only focus on the retina [5,6], and they are ineffective when pathologies irremediably damage the retina or the optic nerve [7,8].”
    Quote in the paperSubstantial claim0 of 4 sources checked
    • cites [5] Scholl, 2016, Emerging therapies for inherited retinal degeneration, Sci. Transl. Med. source

      Not checked in the free run.

    • cites [6] Xue, 2020, Correcting visual loss by genetics and prosthetics, Curr. Opin. Physiol. source

      Not checked in the free run.

    • cites [7] Mirochnik, 2019, Contemporary approaches to visual prostheses, Mil. Med. Res. source

      Not checked in the free run.

    • cites [8] Cehajic-Kapetanovic, 2022, Bioengineering strategies for restoring vision, Nat. Biomed. Eng. source

      Not checked in the free run.

  • May combine two claims.

    Premisenone given

    Multiple visual prostheses have been granted FDA approval and CE mark for clinical use, and many others are in preclinical and clinical validation.

    “With multiple devices granted Food and Drug Administration (FDA) approval and CE mark for clinical use and many others in preclinical and clinical validation, visual prostheses represent a viable therapeutic solution to improve mobility and daily-life activities in blind individuals.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    RP is a set of rare inherited retinal rod-cone dystrophies causing loss of night vision and constriction of the visual field, later followed by cone dysfunction and eventually total blindness.

    “Unlike AMD, RP is a set of rare inherited retinal rod-cone dystrophies, causing loss of night vision and the constriction of the visual field (tunnel vision), later followed by cone dysfunction and eventually total blindness (figure 4(c)) [5,22].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [5] Scholl, 2016, Emerging therapies for inherited retinal degeneration, Sci. Transl. Med. source

      Not checked in the free run.

    • cites [22] Hamel, 2006, Retinitis pigmentosa, Orphanet J. Rare Dis. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Premisenone given

    AMD is the most preeminent pathology amongst outer retinal diseases.

    “AMD is the most preeminent pathology amongst outer retinal diseases.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationreasoning

    Significant technological advances make visual prostheses a valuable solution for blind patients.

    “Although clinical trials showed that vision restoration is still far away, significant technological advances make visual prostheses a valuable solution for blind patients.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Outer retinal diseases are the major causes of incurable blindness in the western world.

    “These diseases are the major causes of incurable blindness in the western world [21].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [21] Gregory-Evans, 1998, Genetic blindness: current concepts in the pathogenesis of human outer retinal dystrophies, Trends Genet. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisereasoning

    Most work to date has focused on retinal stimulation, which quickly became the preferred strategy because it uses the downstream natural process of visual information.

    “Most of the work to date has been focused on retinal stimulation, which quickly became the preferred strategy since it uses the downstream natural process of visual information.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based). May combine two claims.

    Interpretationnone given

    The optic nerve is a target to elicit phosphenes and could have a broader range of applications than retinal prostheses.

    “The optic nerve is also a target to elicit phosphenes and could have a broader range of applications than retinal prostheses.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    The visual cortex is a target for all blindness except cortical injuries and stroke.

    “Similarly, the visual cortex is a target for all blindness, but cortical injuries and stroke.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    The presence of debris due to photoreceptor degeneration might increase the distance from the electrodes to BCs and reduce resolution and stimulation efficiency.

    “However, the presence of debris due to photoreceptor degeneration might increase the distance from the electrodes to BCs and reduce resolution and stimulation efficiency [50].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [50] Flores, 2018, Optimization of pillar electrodes in subretinal prosthesis for enhanced proximity to target neurons, J. Neural Eng. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    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].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [48] Palanker, 2020, Photovoltaic restoration of central vision in atrophic age-related macular degeneration, Ophthalmology source

      Not checked in the free run.

    • cites [49] Palanker, 2022, Simultaneous perception of prosthetic and natural vision in AMD patients, Nat. Commun. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    After a few months of training, the patient distinguished line orientations and identified characters despite having only four electrodes.

    “After a few months of training, the patient distinguished line orientations and identified characters despite having only four electrodes [65][66][67].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [65][66][67]

      Not checked in the free run.

  • May combine two claims.

    Premisereasoning

    Phosphenes were irregular in shape and not stable over time.

    “However, phosphenes were irregular in shape and not stable over time.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The LGN presents retinotopic organisation and well-defined physical separation of the parvocellular and magnocellular pathways.

    “Third, LGN presents retinotopic organisation and well-defined physical separation of the parvocellular and magnocellular pathways, respectively relaying information about small, slow, colourful things (parvocellular; high spatial frequency information; low temporal frequency information) and large, fast, and colourless things (magnocellular; low spatial frequency; high temporal frequency) [37,80].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [37] Lewis, 2015, Restoration of vision in blind individuals using bionic devices: a review with a focus on cortical visual prostheses, Brain Res. source

      Not checked in the free run.

    • cites [80] Abbasi, 2021, Advances in neuroscience, not devices, will determine the effectiveness of visual prostheses, Semin. Ophthalmol. source

      Not checked in the free run.

  • May combine two claims.

    Premisereasoning

    Suprachoroidal prostheses aim at the stimulation of BCs, but the considerable distance between the electrodes and the retina is a major issue.

    “Suprachoroidal prostheses aim at the stimulation of BCs, but the considerable distance between the electrodes and the retina is a major issue.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Retinal tacks lose mechanical stability over time, which can increase the distance between electrodes and the retina and consequently increase the current required for retinal stimulation and reduce resolution.

    “Retinal tacks also lose mechanical stability over time, which can increase the distance between electrodes and the retina and, in consequence, increase the current required for retinal stimulation and reduce resolution [43][44][45].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [43][44][45]

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Premisenone given

    The relatively small diameter of the optic nerve facilitates the electrical stimulation of a wide visual field.

    “Moreover, the relatively small diameter of the optic nerve facilitates the electrical stimulation of a wide visual field.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisereasoning

    Subretinal prostheses do not need fixation with retinal tacks and have greater mechanical stability.

    “Therefore, they do not need fixation with retinal tacks and have greater mechanical stability.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Suprachoroidal prostheses have good mechanical stability without fixation with retinal tacks and, like epiretinal prostheses, good heat dissipation capacity and allow the insertion of large arrays.

    “Like subretinal prostheses, they have good mechanical stability without fixation with retinal tacks [56,58] and, like epiretinal prostheses, they have good heat dissipation capacity and allow the insertion of large arrays [57].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [56] Eggenberger, 2021, Implantation and long-term assessment of the stability and biocompatibility of a novel 98 channel suprachoroidal visual prosthesis in sheep, Biomaterials source

      Not checked in the free run.

    • cites [58] Fujikado, 2016, One-year outcome of 49-channel suprachoroidal-transretinal stimulation prosthesis in patients with advanced retinitis pigmentosa, Investigative Ophthalmol. Vis. Sci. source

      Not checked in the free run.

    • cites [57] Ayton, 2014, First-in-human trial of a novel suprachoroidal retinal prosthesis, PLoS One source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The LGN is a stratified compact structure in the thalamus receiving input from the optic nerve and relaying information to the primary visual cortex.

    “The LGN is a stratified compact structure in the thalamus receiving input from the optic nerve and relaying information to the primary visual cortex [7].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [7] Mirochnik, 2019, Contemporary approaches to visual prostheses, Mil. Med. Res. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The patient reported phosphenes and described them by their position, shape, number of dots, colour and dimension.

    “The patient reported phosphenes and described them by their position, shape, number of dots, colour and dimension.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationreasoning

    The C-Sight implant is too rigid compared to the nerve tissue and is therefore unsuitable for chronic implantation.

    “However, this implant is too rigid compared to the nerve tissue and is therefore unsuitable for chronic implantation.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Due to the considerable distance from BCs, high current amplitudes are required for retinal stimulation, possibly leading to damage due to overstimulation.

    “Due to the considerable distance from BCs, high current amplitudes are required for retinal stimulation, possibly leading to damage due to overstimulation [35,61].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [35] Ayton, 2019, An update on retinal prostheses, Clin. Neurophysiol. source

      Not checked in the free run.

    • cites [61] Bloch, 2019, Advances in retinal prosthesis systems, Ther. Adv. Ophthalmol. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    GENNARIS consists of 11 modules with 43 electrodes each.

    “The GENNARIS (Monash Vision Group) consists of 11 modules with 43 electrodes each (figure 6(d)) [106].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [106] Rosenfeld, 2020, Tissue response to a chronically implantable wireless intracortical visual prosthesis (Gennaris array), J. Neural Eng. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationnone given

    Quantitative limitations in artificial vision are a product of both technological and biological challenges.

    “Quantitative limitations in artificial vision are a product of both technological and biological challenges, which will be addressed in the following paragraphs, together with potential solutions.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    The first cortical prosthesis had only four intracortical electrodes but was able to evoke some visual percepts in the subject.

    “The first cortical prosthesis had only four intracortical electrodes [86,87] but was able to evoke some visual percepts in the subject [88].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [86] JC, 1958, Electronics brings light to the blind, Radio Electron.

      Not checked in the free run.

    • cites [87] Button, 1962, Visual responses to cortical stimulation in the blind, J. Iowa Med. Soc.

      Not checked in the free run.

    • cites [88] Lewis, 2016, Electrical stimulation of the brain and the development of cortical visual prostheses: an historical perspective, Brain Res. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Intracortical prostheses are more invasive but take advantage of the close contact between the electrodes and the neurons to provide a more selective stimulation at much lower current amplitudes.

    “Intracortical prostheses are more invasive but take advantage of the close contact between the electrodes and the neurons to provide a more selective stimulation at much lower current amplitudes [100, 101].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [100] Chen, 2020, Shape perception via a high-channel-count neuroprosthesis in monkey visual cortex, Science source

      Not checked in the free run.

    • cites [101] Caspi, 2021, Eye movements and the perceived location of phosphenes generated by intracranial primary visual cortex stimulation in the blind, Brain Stimul. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Evoked phosphenes with intracortical prostheses are smaller and closer.

    “Therefore, evoked phosphenes are smaller and closer.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    So far, retinal prostheses have reached marketing approval, and other devices are in preclinical and clinical testing.

    “So far, retinal prostheses have reached marketing approval [23,53,111], and other devices are in preclinical and clinical testing.”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [23] Muqit, 2019, Six-month safety and efficacy of the intelligent retinal implant system II device in retinitis pigmentosa, Ophthalmology source

      Not checked in the free run.

    • cites [53] Edwards, 2018, Assessment of the electronic retinal implant alpha AMS in restoring vision to blind patients with end-stage retinitis pigmentosa, Ophthalmology source

      Not checked in the free run.

    • cites [111] Luo, 2016, The Argus® II retinal prosthesis system, Prog. Retin. Eye Res. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    CORTIVIS uses a Utah array with 100 electrodes.

    “The CORTIVIS (Miguel Hernández University of Elche) uses a Utah array with 100 electrodes [107].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [107] Fernández, 2021, Visual percepts evoked with an intracortical 96-channel microelectrode array inserted in human occipital cortex, J. Clin. Invest. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    In animals, LGN microstimulation produced simple discrete visual percepts and visual cortical responses similar to those elicited by natural vision.

    “In animals, LGN microstimulation produced simple discrete visual percepts [81] and visual cortical responses similar to those elicited by natural vision [82].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [81] Pezaris, 2007, Demonstration of artificial visual percepts generated through thalamic microstimulation, Proc. Natl Acad. Sci. source

      Not checked in the free run.

    • cites [82] Panetsos, 2011, Consistent phosphenes generated by electrical microstimulation of the visual thalamus. An experimental approach for thalamic visual neuroprostheses, Front. Neurosci. source

      Not checked in the free run.

  • May combine two claims.

    Premisenone given

    The volunteer, a blind subject with glaucoma, perceived phosphenes and recognised simple patterns.

    “The volunteer, a blind subject with glaucoma, perceived phosphenes and recognised simple patterns.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Epicortical prostheses are less invasive since they do not penetrate the brain, as confirmed by a post-mortem study on a patient implanted by Dobelle who retained the epicortical array for 36 years.

    “Epicortical prostheses are less invasive since they do not penetrate the brain, as confirmed by a post-mortem study on a patient implanted by Dobelle, who retained the epicortical array for 36 years (figure 6(c)) [77].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [77] Towle, 2020, Postmortem investigation of a human cortical visual prosthesis that was implanted for 36 years, J. Neural Eng. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    ICVP is developing a wireless floating microelectrode array with 16 microelectrodes.

    “The ICVP (Illinois University of Technology) is developing a wireless floating microelectrode array with 16 microelectrodes [108].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [108] Troyk, 2016 source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The distance between epicortical electrodes and neurons reduces the spatial resolution of artificial vision, and high currents might be unsafe due to the risk of seizures.

    “This distance reduces the spatial resolution of artificial vision [99], and high currents might be unsafe due to the risk of seizures [88].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [99] Schmidt, 1996, Feasibility of a visual prosthesis for the blind based on intracortical micro stimulation of the visual cortex, Brain source

      Not checked in the free run.

    • cites [88] Lewis, 2016, Electrical stimulation of the brain and the development of cortical visual prostheses: an historical perspective, Brain Res. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S4 (based).

    Interpretationnone given

    Object identification and recognition require devices that are able to provide a high enough resolution during artificial vision.

    “Object identification and recognition require devices that are able to provide a high enough resolution during artificial vision.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    The two approaches to avoid axonal stimulation (selective direct stimulation and epiretinal network-mediated stimulation) point towards different directions, and today they seem mutually exclusive.

    “The two approaches to avoid axonal stimulation (selective direct stimulation and epiretinal network-mediated stimulation) point towards different directions, and today they seem mutually exclusive.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Most of the primary visual cortex surface lies in the interhemispheric area and the calcarine fissure, creating a hurdle for developing wide-angle cortical prostheses.

    “Most of the primary visual cortex surface lies in the interhemispheric area and the calcarine fissure [102], creating a hurdle for developing wide-angle cortical prostheses.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [102] Schira, 2012, Brain mapping: the (un)folding of striate cortex, Curr. Biol. source

      Not checked in the free run.

  • May combine two claims.

    Premisereasoning

    The wireless photovoltaic solution avoids a trans-scleral cable, which is known to limit the maximum number and density of electrodes and to induce post-operative complications such as eye inflammation or leakage through the incision.

    “This wireless solution avoids a trans-scleral cable which are known to limit the maximum number and density of electrodes on the device and to induce post-operative complications such as eye inflammation or leakage through the incision.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Interpretationcitation

    Electrode size is not the only limiting factor, and further reducing the electrode diameter might not correlate to better resolution.

    “However, the electrode size is not the only limiting factor, and further reducing the electrode diameter might not correlate to better resolution [142].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [142] Behrend, 2011, Resolution of the epiretinal prosthesis is not limited by electrode size, IEEE Trans. Neural Syst. Rehabil. Eng. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Both the optic nerve and LGN are compact, making it easier to access the entire visual field of one eye (optic nerve) or a whole hemifield (LGN) with a single implant.

    “Both the optic nerve and LGN are compact, making it easier to access the entire visual field of one eye (optic nerve) or a whole hemifield (LGN) with a single implant.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Subretinal prostheses are typically small in size, since large subretinal implants might encounter considerable difficulty in the surgical placement and represent a high risk of retinal detachment.

    “Subretinal prostheses are typically small in size, since large subretinal implants might encounter considerable difficulty in the surgical placement and represent a high risk of retinal detachment [32].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [32] Yue, 2016, Retinal stimulation strategies to restore vision: fundamentals and systems, Prog. Retin. Eye Res. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    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].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [48] Palanker, 2020, Photovoltaic restoration of central vision in atrophic age-related macular degeneration, Ophthalmology source

      Not checked in the free run.

    • cites [133] Zrenner, 2016 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Interpretationreasoning

    Epiretinal prostheses with higher pixel density and targeting network-mediated stimulation might overcome these issues and provide high resolution.

    “Epiretinal prostheses with higher pixel density and targeting network-mediated stimulation might overcome these issues and provide high resolution.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Interpretationcitation

    Placing the electrodes in higher visual areas could be a possible solution to enlarge artificial vision.

    “Although placing the electrodes in higher visual areas [103] could be a possible solution to enlarge artificial vision.”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [103] Meikle, 2022, Neurophysiological considerations for visual implants, Brain Struct. Funct. source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationnone given

    An open challenge for both subretinal (PRIMA) and epiretinal (POLYRETINA) photovoltaic implants is projecting wide-angle images through the pupil necessary to increase the visual field size.

    “Yet, an open challenge for both subretinal (PRIMA) and epiretinal (POLYRETINA) photovoltaic implants is projecting wide-angle images through the pupil necessary to increase the visual field size.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Interpretationcitation

    A fixed electrode number reduces the electrode density if electrodes are spread over a wider surface area, which might worsen visual resolution.

    “A fixed electrode number reduces the electrode density if electrodes are spread over a wider surface area, which might worsen visual resolution [125].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [125] Waschkowski, 2014, Development of very large electrode arrays for epiretinal stimulation (VLARS), Biomed. Eng. source

      Not checked in the free run.

  • May combine two claims.

    Premisenone given

    Subretinal implants are further away from the GL, and usually induce circular phosphenes.

    “Subretinal implants are further away from the GL, and usually induce circular phosphenes.”
    Quote in the paperNot a substantial claim

  • Classified as probably not a substantial claim.

    Interpretationcitation

    One solution to improve resolution in epiretinal stimulation would be to selectively activate individual RGCs by establishing a one-to-one connection between RGCs and electrodes.

    “One solution would be to selectively activate individual RGCs by establishing a one-to-one connection between RGCs and electrodes [137].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [137] Gogliettino, 2022, High-fidelity restoration of visual signals by electrical stimulation in the central primate retina source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisenone given

    Most studies regarding spatial resolution have been conducted with retinal implants.

    “So far, most studies regarding spatial resolution have been conducted with retinal implants.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

    Interpretationreasoning

    In retinal stimulation, photovoltaic technology is intuitive since the retina is designed to absorb the light entering from the pupil.

    “In retinal stimulation, photovoltaic technology is intuitive since the retina is designed to absorb the light entering from the pupil.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Premisecitation

    Increasing the pulse duration or using non-rectangular pulses facilitates network-mediated stimulation.

    “Otherwise, increasing the pulse duration [31] or using non-rectangular pulses [29] facilitates network-mediated stimulation.”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [31] Weitz, 2015, Improving the spatial resolution of epiretinal implants by increasing stimulus pulse duration, Sci. Transl. Med. source

      Not checked in the free run.

    • cites [29] Chenais, 2019, Capacitive-like photovoltaic epiretinal stimulation enhances and narrows the network-mediated activity of retinal ganglion cells by recruiting the lateral inhibitory network, J. Neural Eng. source

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Interpretationnone given

    Increasing spatial resolution means increasing the number of separable phosphenes per unit area evoked in the patient's visual field.

    “In other words, increasing spatial resolution means increasing the number of separable phosphenes per unit area evoked in the patient's visual field.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Exploiting conformable or foldable substrates has two advantages: ease of insertion during surgery and improved contact with neural tissue.

    “Exploiting conformable or foldable substrates has two advantages: ease of insertion during the surgical procedure and improved contact with the neural tissue [176].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [176] Fallegger, 2020, Conformable hybrid systems for implantable bioelectronic interfaces, Adv. Mater. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    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].”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [48] Palanker, 2020, Photovoltaic restoration of central vision in atrophic age-related macular degeneration, Ophthalmology source

      Not checked in the free run.

    • cites [154] Hafed, 2016, Oculomotor behavior of blind patients seeing with a subretinal visual implant, Vis. Res. source

      Not checked in the free run.

  • Classified as probably not a substantial claim. May combine two claims.

    Interpretationreasoning

    Visual prostheses could benefit from current-steering approaches that would limit the extent of the activated tissue during stimulation, reducing the risk of cross-talk and increasing the spatial selectivity.

    “Visual prostheses could benefit from current-steering approaches that would limit the extent of the activated tissue during stimulation, reducing the risk of cross-talk and increasing the spatial selectivity.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    POLYRETINA is a foldable and injectable photovoltaic epiretinal prosthesis that can be safely delivered with a 6 mm size cut through the sclera and conform better to the curvature of the eye.

    “To overcome this issue, POLYRETINA is a foldable and injectable photovoltaic epiretinal prosthesis that can be safely delivered with a 6 mm size cut through the sclera and conform better to the curvature of the eye [39,38].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [39] Vagni, 2022, POLYRETINA restores light responses in vivo in blind Göttingen minipigs, Nat. Commun. source

      Not checked in the free run.

    • cites [38] Ferlauto, 2018, Design and validation of a foldable and photovoltaic wide-field epiretinal prosthesis, Nat. Commun. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Smaller electrodes have higher charge density stimulation threshold and lower dynamic range, as shown in explanted retinas.

    “Smaller electrodes have higher charge density stimulation threshold and lower dynamic range, as shown in explanted ratinas [160,161].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [160] Damle, 2021, Minimizing iridium oxide electrodes for high visual acuity subretinal stimulation, Eneuro source

      Not checked in the free run.

    • cites [161] Corna, 2018, Electrode-size dependent thresholds in subretinal neuroprosthetic stimulation, J. Neural Eng. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    All biocompatible materials used so far provoke an inflammatory response and some degree of foreign body reaction.

    “It has been shown that all biocompatible materials used so far provoke an inflammatory response and some degree of foreign body reaction [174,175].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [174] Anderson, 2008, Foreign body reaction to biomaterials, Semin. Immunol. source

      Not checked in the free run.

    • cites [175] Salatino, 2017, Glial responses to implanted electrodes in the brain, Nat. Biomed. Eng. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Conductive polymers are considerably softer than metals, flexible and conformable, and have a high charge injection capacity.

    “Conductive polymers have been widely used in implantable devices for research as they are considerably softer than metals, flexible and conformable, and have a high charge injection capacity [166][167][168][169][170].”
    Quote in the paperNot a substantial claim0 of 3 sources checked
    • cites [166] Hassarati, 2014, Stiffness quantification of conductive polymers for bioelectrodes, J. Polym. Sci. B source

      Not checked in the free run.

    • cites [167] Ferlauto, 2018, Development and characterization of PEDOT:PSS/alginate soft microelectrodes for application in neuroprosthetics, Front. Neurosci. source

      Not checked in the free run.

    • cites [168] Fanelli, 2021, Transient neurovascular interface for minimally invasive neural recording and stimulation, Adv. Mater. Technol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Phosphene fading affects retinal prostheses and makes continuous perception above flicker fusion nearly impossible.

    “which affects retinal prostheses and makes continuous perception above flicker fusion nearly impossible.”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [148] Fornos, 2012, Temporal properties of visual perception on electrical stimulation of the retina, Investigative Opthalmol. Vis. Sci. source

      Not checked in the free run.

    • cites [149] Stronks, 2014, The functional performance of the Argus II retinal prosthesis, Expert Rev. Med. Device source

      Not checked in the free run.

    • cites [150] Stingl, 2013, Artificial vision with wirelessly powered subretinal electronic implant alpha-IMS, Proc. R. Soc. B source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Leads-wires breakage is common and leads to malfunctioning or not functioning of the device.

    “Leads-wires breakage is common [35] and leads to malfunctioning or not functioning of the device.”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [35] Ayton, 2019, An update on retinal prostheses, Clin. Neurophysiol. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Selection for retinal prostheses is based on retinal imaging to verify structural integrity and corneal stimulation with lens electrodes to verify retinal excitability.

    “Among other criteria, the selection for retinal prostheses is based on retinal imaging to verify structural integrity [217] and corneal stimulation with lens electrodes to verify the retinal excitability [217][218][219].”
    Quote in the paperSubstantial claim0 of 3 sources checked
    • cites [217] Finn, 2018, Argus II retinal prosthesis system: a review of patient selection criteria, surgical considerations, and post-operative outcomes, Clin. Ophthalmol. source

      Not checked in the free run.

    • cites [218] Yanai, 2003, The value of preoperative tests in the selection of blind patients for a permanent microelectronic implant, Trans. Am. Ophthal. Soc.

      Not checked in the free run.

    • cites [219] Naycheva, 2012, Phosphene thresholds elicited by transcorneal electrical stimulation in healthy subjects and patients with retinal diseases, Investigative Opthalmol. Vis. Sci. source

      Not checked in the free run.

  • May combine two claims.

    Interpretationcitation

    So far, retinal prostheses have been implanted in end-stage RP patients which are not enough to make a profitable market.

    “So far, retinal prostheses have been implanted in end-stage RP patients which are not enough to make a profitable market [228].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [228] Strickland, 2022, What happens when a bionic body part becomes obsolete?, IEEE Spectr. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    The Argus II device is now obsolete, and users declared not having technical support if their implant will stop working.

    “The device is now obsolete, and users declared not having technical support if their implant will stop working [228].”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [228] Strickland, 2022, What happens when a bionic body part becomes obsolete?, IEEE Spectr. source

      Not checked in the free run.

  • May combine two claims.

    Premisecitation

    Companies have had to face economic problems related to limited market size, cost of research and development, regulatory approval, and low acceptance of the device by clinicians and patients.

    “Companies have had to face economic problems related to limited market size, cost of research and development, regulatory approval, and low acceptance of the device by clinicians and patients [229].”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [229] Chevrie, 2020, Navigating the regulatory pathway for an innovative bionic vision system source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    Machine learning could play a role in optimising stimulation parameters to create more naturalistic electrical stimulation patterns, as shown for optic nerve and cortical prostheses.

    “Machine learning could also play a role in optimising stimulation parameters to create more naturalistic electrical stimulation patterns, as shown for optic nerve [192] and cortical [193] prostheses.”
    Quote in the paperNot a substantial claim0 of 2 sources checked
    • cites [192] Romeni, 2021, A machine learning framework to optimize optic nerve electrical stimulation for vision restoration, Patterns source

      Not checked in the free run.

    • cites [193] Lozano, 2019, Understanding the brain function and emotions

      Not checked in the free run.

  • May combine two claims.

    Interpretationreasoning

    Light-based technologies are convenient for retinal implants but are not well suited for other visual prostheses which do not have a natural transparent window to light.

    “While light-based technologies are convenient for retinal implants, they are not well suited for other visual prostheses which do not have a natural transparent window to light.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim. May combine two claims.

    Premisecitation

    The number of people affected by RP is estimated to be about 1.5-2 million, but only 12% of these have a visual acuity worse than counting fingers and 0.5% have no perception of light.

    “The number of people affected by RP is estimated to be about 1.5-2 million [226], but only 12% of these have a visual acuity worse than counting fingers and 0.5% have no perception of light [227].”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [226] Allen, 2021, Retinal prostheses: where to from here?, Clin. Exp. Ophthalmol. source

      Not checked in the free run.

    • cites [227] Grover, 1999, Visual acuity impairment in patients with retinitis pigmentosa at age 45 years or older, Ophthalmology source

      Not checked in the free run.

70 of 70

  • The authors state this as an assumption.

    Neuroplasticity triggered by learning and rehabilitation will improve artificial vision over time.

    “Initially, phosphenes might be irregular and difficult to interpret, but it is assumed that neuroplasticity triggered by learning and rehabilitation will improve artificial vision over time (figure 3(b)) [20].”

  • The paper relies on this without support.

    The entire visual field is mapped over the anatomical area in all structures mentioned (retina, optic nerve, LGN and V1).

    “The entire visual field is mapped over the anatomical area in all the structures mentioned (retina, optic nerve, LGN and V1).”

  • The paper relies on this without support.

    Stimulation parameters play a crucial role in the characteristics of phosphenes, such as brightness, duration, size or colour.

    “The stimulation parameters play a crucial role in the characteristics of phosphenes, such as brightness, duration, size or colour.”

  • The paper relies on this without support.

    When stimulation resolution is low, phosphenes might fuse into a blob during synchronous activation of multiple electrodes.

    “When the stimulation resolution is low, as it is for the Argus® II or epicortical visual prostheses, it has been shown that phosphenes might fuse into a blob during synchronous activation of multiple electrodes.”

  • The paper relies on this without support.

    Artificial vision can be hampered by poor temporal resolution.

    “Artificial vision can also be hampered by poor temporal resolution.”

  • The paper relies on this without support.

    Little is known about visual targets other than the retina.

    “Meanwhile, little is known about other visual targets.”

  • The paper relies on this without support.

    Decreasing electrode size imposes constraints on the electrode material to maintain low impedance and high charge injection capacity.

    “However, decreasing the electrode size imposes constraints on the electrode material to maintain low impedance and high charge injection capacity.”

  • The paper relies on this without support.

    Exceeding the charge injection limit of electrodes will cause irreversible damage to both electrodes and tissue.

    “Exceeding the charge injection limit of electrodes will cause irreversible damage to both electrodes and tissue.”

  • The paper relies on this without support.

    Matching neural tissue mechanical properties with implanted ones would help improve long-term stability and efficacy of stimulation.

    “For visual prostheses, regardless of whether they are epineural or intraneural, matching the neural tissue mechanical properties with the implanted ones would help in improving the long-term stability and efficacy of the stimulation.”

  • The paper relies on this without support.

    Visual information processing is a crucial step.

    “Visual information processing is a crucial step.”

  • The paper relies on this without support.

    Saliency detection works efficiently for image or static object recognition tasks.

    “This method works efficiently for image or static object recognition tasks.”

  • The paper relies on this without support.

    A drawback of machine learning methods is the high training cost required for good accuracy.

    “A drawback of these methods is the high training cost required for good accuracy.”

  • The paper relies on this without support.

    Phosphene maps are specific to each patient and might change over time.

    “Such a customised approach is needed because phosphenes maps are specific to each patient and might change over time.”

  • The paper relies on this without support.

    Most image processing algorithms and closed-loop approaches have been tested so far in-silico or in-vitro.

    “Most of the image processing algorithms and the closed-loop approaches have been tested so far in-silico or in-vitro.”

  • The paper relies on this without support.

    Neurostimulation has been routinely performed with electrodes wired to an electric pulse generator.

    “Neurostimulation has been routinely performed with electrodes wired to an electric pulse generator.”

  • The paper relies on this without support.

    In general, a prosthesis is validated for its efficacy in animal models.

    “In general, a prosthesis is validated for its efficacy in animal models.”

  • The paper relies on this without support.

    It remains unclear whether experimental animals are appropriate models to predict efficacy in humans.

    “However, it remains unclear whether experimental animals are appropriate models to predict efficacy in humans.”

  • The paper relies on this without support.

    Even when blind animal models are used, it is difficult to establish how well they reflect human diseases.

    “Even when blind animal models are used, it is difficult to establish how well they reflect human diseases.”

  • The paper relies on this without support.

    Remodelling might be extremely variable from patient to patient.

    “In addition, remodelling might be extremely variable from patient to patient.”

  • The paper relies on this without support.

    Variability could also be found in residual oculomotor behaviour, cellular preservation along the visual pathway, and remaining neuroplasticity.

    “Variability could also be found in the residual oculomotor behaviour, cellular preservation along the visual pathway, and remaining neuroplasticity.”

  • The paper relies on this without support.

    The downside of qualitative functional vision tests is limited relevance out of a controlled laboratory environment.

    “The downside of these tests is the limited relevance out of a controlled laboratory environment.”

  • The paper relies on this without support.

    Medical device regulation is a crucial step for any kind of neuroprosthetic device.

    “Medical device regulation is another crucial step for any kind of neuroprosthetic device.”

  • The paper relies on this without support.

    Neurotechnology is a rapidly growing field, with several new companies entering the business.

    “Neurotechnology is a rapidly growing field, with several new companies entering the business.”
23 of 23

Cites

Flagged first, then by citations

Research works printed but not linked: 5

  1. LeRoy, 1755, Mémoire où l’on rend compte de quelques tentatives que l’on a faites pour guérir plusieurs maladies par l’électricité, Hist. Acad. R. Sci., 60, 87
  2. Foerster, 1929, Beitrage zur pathophysiologie der sehbahn und der spehsphare, J. Psychol. Neurol., 39, 435
  3. JC, 1958, Electronics brings light to the blind, Radio Electron., 29, 53
  4. Button, 1962, Visual responses to cortical stimulation in the blind, J. Iowa Med. Soc., 52, 17
  5. Michael, 2020, Video-mode percepts are smaller than sums of single-electrode phosphenes with the Orion® visual cortical prosthesis, Investigative Ophthalmol. Vis. Sci., 61, 927

Cited by

Sorted by citations

Related

Authors
Borda, E., & Ghezzi, D.
Affiliations
École Polytechnique Fédérale de Lausanne (CH)
Corresponding author
Ghezzi, Diego
ORCID
Ghezzi, Diego
Venue
Progress in Biomedical Engineering
Publisher
IOP Publishing
Published
2022-07-01
Volume
4
Issue
3
Pages
032003
ISSN
2516-1091 (ISSN-L)
DOI
10.1088/2516-1091/ac812c
OpenAlex
W4285495317
Semantic Scholar
3b6925ab0142dc85a604e582d0eb39235b7e56ed
Cited by
44
References
222
Citations by year
2026: 1 · 2025: 14 · 2024: 17 · 2023: 11 · 2022: 1
FWCI
4.75
Type
journal article
Language
en
Open access
Licence
Locations
  • Progress in Biomedical Engineering (publishedVersion, cc-by)
  • Infoscience (Ecole Polytechnique Fédérale de Lausanne) (submittedVersion, cc-by-nc-nd)
Funders
  • Medtronic
  • École Polytechnique Fédérale de Lausanne
Topics
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neural Engineering
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Tactile and Sensory Interactions
  • Health Sciences › Medicine › Anesthesiology and Pain Medicine › Pain Management and Treatment
Keywords
retinal prosthesis, blindness, vision restoration, biomedical implants, artificial vision, open problems

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Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Claims read by deepseek-v4.1-flash under definition version 3 (extract-v3) on 2026-10-08.

Classified by jev-1.13-20260917 (gold-guideline-v0.2) on 2026-10-08.

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