The Argus II epiretinal prosthesis system allows letter and word reading and long-term function in patients with profound vision loss

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The Argus II epiretinal prosthesis system
allowsletter and word reading and long-term
functionin patients with profound vision loss

• Lyndon da Cruz, Brian F Coley, Jessy Dorn,
  Francesco Merlini, Eugene Filley,
• Punita Christopher, Fred K Chen, Varalakshmi
  Wuyyuru, Jose Sahel,
• Paulo Stanga, Mark Humayun, Robert J Greenberg,
  Gislin Dagnelie, for the
• Argus II Study Group

Br J Ophthalmol 2013015. doi
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Overview

• Clinical Problem RP
• Overview of Retinal Prosthesis
• Argus II Basic Design and function
• Aim
• Methods
• Results
• Discussion
• Challenges/Limitations
• Conclusion
• Questions

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Retinitis Pigmentosa
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Retinal Prosthesis History

• Charles LeRoy in
• 1755 discharged a large
• capacitor through the
• head of a blind person,
• who described flames
• descending downwards
• (Marg, 1991)

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Retinal Prosthesis Concept
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Retinal Prosthesis Options

• Argus II
• Visual Cortical Implant
• Virtual Retinal Display (VRD)
• Microsystem-based Visual Prosthesis (MIVIP)
• Artificial Silicon Retina (ASR)
• Tübingen MPDA Project Alpha IMS
• Implantable Miniature Telescope
• Dobelle Eye

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The external equipment

• The external equipment includes glasses, a video
  processing unit (VPU) and a cable.

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• How Is Argus II Designed To Produce Sight?

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Testimonials

• The F.D.A. Approves a Bionic Eye Argus II Device
  Helps the Blind YouTube
• Argus II, Manchester User Testimonial -
  Artificial Retina - Bionic Eye - YouTube

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Aim

• To determine whether a group of patients blinded
  by outer retinal dystrophies and fitted with the
  Argus II system, could identify letters and words
  on a computer screen.
• (effective spatial resolution, in the context
  of a device that is stable, portable and capable
  of long-term function)

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Subjects
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Methods

• Test I letter identification
• Test II letter size reduction
• Test III word recognition
• Conditions System off and both eyes unpatched
  system on in scrambled mode with eyes patched
  and unpatched and system in standard mode with
  eyes patched and unpatched

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Results
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Figure 2
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Figure 3
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Challenges

• Safety
• Surgery
• Effectiveness
• Suitability
• Cost
• Contraindications
• Electrodes packaging

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Conclusion

• Multiple blind subjects fitted with the Argus II
  system consistently identified letters and words
  using the device, indicating reproducible spatial
  resolution.
• This, in combination with stable, long-term
  function, represents significant progress in the
  evolution of artificial sight.

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Questions

• What is Argus II ?
• What are advantages of Argus II?
• Argus II has therapeutic potential for what other
  types of retinal diseases?
• Argus II vs. other Retinal Prosthesis
• What experiments would you suggests to further
  test effectiveness of Argus II?