The Argus II epiretinal prosthesis system allowsletter and word reading and long-term function

in 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 theArgus II Study Group

Br J Ophthalmol 2013;0:1–5. doi

Overview

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

Retinitis Pigmentosa

Charles LeRoy in

1755 discharged a large

capacitor through the

head of a blind person,

who described “flames

descending downwards”

(Marg, 1991)

Retinal Prosthesis History

Retinal Prosthesis Concept

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

The external equipment

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

• How Is Argus® II Designed To Produce Sight?

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

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)

Subjects

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

Results

Figure 2

Figure 3

Challenges

• Safety

• Surgery

• Effectiveness

• Suitability

• Cost

• Contraindications

• Electrodes packaging

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.

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?