Argus® II Retinal Stimulation System Feasibility Protocol

Investigational Phase of the Study:

The objective of this feasibility study is to evaluate the safety and utility of the Argus II Retinal Stimulation System in providing visual function to blind subjects with retinitis pigmentosa.

Post-Approval Phase of the Study:

To collect post-approval data in order to monitor the ongoing safety and reliability of the Argus II System

During the post-approval phase, subjects will undergo annual eye exams, assessments of medical status and adverse events, and measurement of stimulation thresholds. In addition, at the mutual agreement of the investigator and the subject, subjects will have the option of participating in psychophysical research which could occur as frequently as monthly. Functional tests at 10 years: photographic flash, square localization, direction of motion and grating visual acuity.

Eligibility Criteria:
Inclusion Criteria:

* A confirmed history of retinitis pigmentosa (all centers) or outer retinal degeneration (France, U.K., Switzerland, Mexico only) with remaining visual acuity of bare light perception (all centers) or 2.3 logMAR (France, U.K., Switzerland, Mexico only) or worse in both eyes.
* Functional ganglion cells and optic nerve as determined by a measurable electrically evoked response or documented light perception.
* A history of former useful form vision in the worse-seeing eye.
* Must be at least the following age at the time of enrollment: 25 (USA, Switzerland) or 18 (France, U.K., and Mexico) years old
* Must reside within 2 hours (USA, UK and Mexico) or 3 hours (France and Switzerland) distance (by ground transportation) of the investigational site.
* Must be willing and able to comply with the protocol testing and follow-up requirements.

Exclusion Criteria:

* Optic Nerve disease

  * History of glaucoma
  * Optic neuropathy or other confirmed damage to optic nerve or visual cortex damage
* Diseases or conditions that effect retinal function including but not limited to:

  * Central retinal artery/vein occlusion (CRAO or CRVO)
  * End-stage diabetic retinopathy
  * Retinal detachment or history of retinal detachment
  * Trauma
  * Infectious or inflammatory retinal diseases
* Diseases or conditions that prevent adequate visualization of the retina including, but not limited to corneal degeneration that cannot be resolved before implant.
* Diseases or conditions of the anterior segment that prevent the ability to adequately perform the physical examination including but not limited to trauma or lid malpositions.
* Diseases of the ocular surface including but not limited to keratitis sicca.
* An ocular condition that predisposes the subject to eye rubbing.
* Any disease or condition that prevents understanding or communication of informed consent, study demands, and testing protocols, including:

  * Cognitive decline including diagnosed forms of dementia and/or progressive neurological disease
  * Psychiatric Disease including diagnosed forms of depression
  * Does not speak a principal language associated with the region
  * Deafness or selective frequency hearing loss that prevents hearing device alarms and alerts.
* Pregnancy
* Subject has another active implantable device (e.g. cochlear implant), or any form of metallic implant in the head
* Conjunctival thinning which may predispose the subject to conjunctival erosion in the area where the implant will be installed extra-ocularly.
* Subject is participating in another investigational drug or device study that may conflict with the objectives, follow-up or testing of this study
* Any health concern that makes general anesthesia inadvisable.
* Subject has unrealistic expectations of the implant.
* Known allergy or contraindication to anticipated pre-operative, intra-operative or post-operative medications.
* Conditions likely to limit life to less than 1 year from the time of screening.
* Diseases or conditions that, in the judgement of the surgeon, impede the ability to implant the device or would prevent the system from functioning for the duration of the study (e.g. strabismus)
* Axial eye length \<21.5 mm or \>26.0 mm in the implanted eye as measured by ultrasound (US only)