Observational Study of the Argus® II Retinal Prosthesis System

Study Overview
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Brief Summary
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The Argus II Retinal Implant is a revolutionary new device, which offers vision to patients who are blind from retinal degeneration - retinitis pigmentosa. These patients have no alternatives. Patients typically can achieve ambulatory vision.

Detailed Description
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This study is an investigator-sponsored, observational, controlled, prospective, single-center study. The purpose of this current study is how it affects people's visual function and activities of daily living and to collect additional data on Argus II users in order to monitor the System's safety. In addition, data about the long-term reliability of the System will be gathered. The Argus II retinal implant will be surgical implanted into patients who are blind but the surgical procedure is not a part of this observational study. Our hypothesis is that the visual results in our hands will be comparable to those reported in the FDA study. We will use the results of this study to plan future enhancements to the service and to explore the use of the device for other blinding conditions.

Official Title
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Observational Study of the Argus® II Retinal Prosthesis System

Conditions
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Retinitis Pigmentosa

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: •Adults, age 25 years or older with severe to profound outer retinal degeneration. but some residual light perception. If no residual light perception remains, the retina must be able to respond to electrical stimulation and previous history of useful form vision. Exclusion Criteria: Ocular diseases or conditions that could prevent the Argus II System from working (e.g. optic nerve disease, central retinal artery or vein occlusion, history of retinal detachment, trauma, severe strabismus). Ocular structures or conditions that could prevent the successful implantation of the Argus II Implant or adequate healing from surgery (e.g. extremely thin conjunctiva, axial length <20.5 mm or > 26 mm, corneal ulcers, choroidal neovascularisation in the area of the intended tack location, etc.). Ocular diseases or conditions (other than cataracts) that prevent adequate visualisation of the inner structures of the eye (e.g. corneal opacity, etc.). Inability to tolerate general anaesthesia or the recommended antibiotic and steroid regimen associated with the implantation surgery. Predisposition to eye rubbing.

Ages Eligible for Study
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Minimum Age: 25 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Safety | The primary endpoint in the study is safety. Safety will be assessed by calculating the proportion of subjects who experience individual procedure- and device-related adverse events. In addition, the proportion of subjects who experience a significant ocular event will also be reported. | Patients will be observed for 1 year post-implant. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Visual function | Visual function: Visual function means how the eye works (e.g. visual acuity). Visual function will be measured using the following tests: Square Localization; Direction of Motion; Grating Visual Acuity (GVA). Functional vision: Functional vision means how subjects perform in vision-related activities of daily living. Function vision will be assessed using the Functional Low-Vision Observer Rated Assessment (FLORA). A utilization questionnaire will also be administered to track how subjects are using the Argus II System. | 1 year |