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Argus® II Retinal Stimulation System Feasibility Protocol

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00407602
Recruitment Status : Completed
First Posted : December 5, 2006
Results First Posted : December 30, 2021
Last Update Posted : January 20, 2022
National Eye Institute (NEI)
Information provided by (Responsible Party):
Second Sight Medical Products

Brief Summary:

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

Condition or disease Intervention/treatment Phase
Retinitis Pigmentosa Device: Implant of Argus II Retinal Prosthesis Not Applicable

Detailed Description:
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.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 30 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Argus® II Retinal Stimulation System Feasibility Protocol
Study Start Date : September 2006
Actual Primary Completion Date : December 31, 2019
Actual Study Completion Date : December 31, 2019

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Implant of Argus II Retinal Prosthesis
This is a single group study where the status and performance of the implanted eye prior to surgery serves as the comparator.
Device: Implant of Argus II Retinal Prosthesis
epiretinal implantation of device

Primary Outcome Measures :
  1. Visual Acuity [ Time Frame: 10 years ]
    Grating Visual Acuity is performed at Baseline and at various timepoints throughout the study. As of the 10 year final testing, the total number of subjects that were able to score on the logMAR scale are indicated below. The device has a scale from 1.6 to 2.9 logMAR. Maximum likelihood estimation of visual acuity is based on BEST-PEST algorithm.

  2. Number of Participants With Adverse Events [ Time Frame: 10 years ]
    Evaluate ocular adverse events reported for all subjects from day of implant through 10 years of study participation

Secondary Outcome Measures :
  1. Massof Activity Inventory [ Time Frame: 3 years ]
    The Massof Activity Inventory measures changes in ability to perform activities of daily living in terms of Goals and Tasks in logits (log-odds units). A logit scale is an equal interval linear scale that represents probability values in terms of real numbers. There is no minimum or maximum scale used in this testing. In this case, a Rasch distribution (using an Andrich rating model) was used to find the maximum likelihood of difficulty of achieving Goals and Tasks, represented in logits. The change in mean logit value between baseline and the 36Month visit for each subject are provided below along with the 95% confidence interval (CI) for the change. A positive change in the Goals or Tasks score which is greater than 0.2 (with a CI less than the mean logit value), is interpreted as a clinically significant increase in functional ability (better outcome).

  2. Quality of Life - Tasks for Daily Living [ Time Frame: 3 years ]
    Quality of life is being measured using the VisQOL survey. This instrument, developed by researchers at the University of Melbourne, Australia, is a vision and quality of life-related utility measure intended to evaluate healthcare interventions for the visually impaired. The utility score is a preference-based measure of vision-related quality of life (Dimension 7 score (Health Dimension Score (1=Best, 0=Worst)). It measures subjective quality of life on a scale of 0 to 1, where 0 represents worst possible quality of life and 1 represents perfect quality of life.

  3. Orientation and Mobility [ Time Frame: 5 years ]
    Argus II System for orientation and mobility, each subject completed two tests (walking to a high-contrast "door" on the wall and following a straight line on the floor) at various timepoints throughout the study. Accuracy (percent of trials where the subject successfully reached the target) was measured with the device system ON and system OFF. Average % success rates across the analysis population are provided for each modality and for each test at the 60 month time point.

  4. Visual Function [ Time Frame: 10 years ]
    Square localization (SL) and Direction of Motion (DOM) testing performed at specific protocol intervals. SL tests ability of subjects to locate high-contrast square on black screen. DOM tests ability of subjects to determine the direction a white bar is moving over a black screen. Each test is performed with the system ON and then compared to performance with the system OFF. Number of subjects who performed significantly better with the system ON is indicated below.

  5. Stability of Implant - 5 Years Post Implant [ Time Frame: 5 years ]
    Stability of electrode array on the retina. Qualitative review of imaging: retinal and array landmarks compared from all time points post implant.

  6. Device Reliability [ Time Frame: 10 years ]
    Number of participants with functional devices 10 years post implant

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

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)

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00407602

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United States, California
Doheny Eye Institute
Los Angeles, California, United States, 90033
University of California San Francisco
San Francisco, California, United States, 94143
United States, Maryland
Johns Hopkins, Wilmer Eye Institute
Baltimore, Maryland, United States, 21205
United States, New York
Columbia University, Department of Ophthalmology, Edward S. Harkness Eye Institute
New York, New York, United States, 10032
United States, Pennsylvania
University of Pennsylvania, Scheie Eye Institute
Philadelphia, Pennsylvania, United States, 19104
Wills Eye Hospital
Philadelphia, Pennsylvania, United States, 19107
United States, Texas
Retina Foundation of the Southwest
Dallas, Texas, United States, 75231
Centre d'Investigation Clinique, Service d'Ophtalmologie, Quinze-Vingts National Eye Hospital, 28 rue de Charenton, 75557 Cedex 12
Paris, France
Puerta de Hierro, Centro Medico, Centro de Retina
Zapopan, Jalisco, Mexico, 51116
Clinique d'Ophthalmologie Hopitaux, Universitaires de Geneve 22 rue Alcide Jentzer 1205
Geneva, Switzerland
United Kingdom
Moorfields Eye Hospital, Vitreoretinal Research Unit
London, United Kingdom, EC1V 2PD
Manchester Royal Eye Hospital
Manchester, United Kingdom
Sponsors and Collaborators
Second Sight Medical Products
National Eye Institute (NEI)
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Study Director: Anne-Marie Ripley Second Sight Medical Products
  Study Documents (Full-Text)

Documents provided by Second Sight Medical Products:
Publications of Results:
Other Publications:
Publications automatically indexed to this study by Identifier (NCT Number):

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Responsible Party: Second Sight Medical Products Identifier: NCT00407602    
Other Study ID Numbers: CP-003-001
National Eye Institute (NEI) ( Other Grant/Funding Number: 2R01EY012893-06A1 )
First Posted: December 5, 2006    Key Record Dates
Results First Posted: December 30, 2021
Last Update Posted: January 20, 2022
Last Verified: January 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No
Keywords provided by Second Sight Medical Products:
retinitis pigmentosa
retinal implant
retinal prosthesis
outer retinal degeneration
Additional relevant MeSH terms:
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Retinitis Pigmentosa
Retinal Diseases
Eye Diseases
Eye Diseases, Hereditary
Retinal Dystrophies
Retinal Degeneration
Genetic Diseases, Inborn