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Experimental and Clinical Studies of Retinal Stimulation

Primary Purpose

Retinitis Pigmentosa

Status
Recruiting
Phase
Not Applicable
Locations
United States
Study Type
Interventional
Intervention
New visual processing unit (VPU) with asymmetric waveforms
New VPU with bipolar stimulation
Sponsored by
University of Michigan
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional other trial for Retinitis Pigmentosa

Eligibility Criteria

25 Years - 89 Years (Adult, Older Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • Must be implanted with an Argus II Retinal Prosthesis system.
  • Have 5 or more electrodes that create a perception with stimulation.
  • Must be willing and able to comply with the protocol testing requirements.

Exclusion Criteria:

  • Subjects participating in another investigatory drug or device study
  • Any disease or condition that prevents understanding or communication of informed consent, study demands, and testing protocols.

Sites / Locations

  • University of MichiganRecruiting

Arms of the Study

Arm 1

Arm Type

Experimental

Arm Label

Retinal stimulation

Arm Description

Alternative stimulus patterns will be tested (vs. baseline). The intervention is the alternative stimulus pattern. The intervention will be tested only in the clinic vs. baseline. The subject will go home with baseline settings. The two alternative stimulus patterns to be tested are asymmetric waveforms and bipolar stimulus.

Outcomes

Primary Outcome Measures

Percent change in stimulus thresholds
Compare baseline threshold with threshold of modified stimulus parameters. Threshold is measured in microCoulumbs ( the product of stimulus duration and stimulus amplitude).
Change in shape perception
As measured by elongation ratio. The elongation ratio is the ratio of major axis length to minor axis length of an ellipse. Subjects will draw shapes on a touch screen and these shapes will be fit to an ellipse.

Secondary Outcome Measures

Full Information

First Posted
July 26, 2018
Last Updated
December 12, 2022
Sponsor
University of Michigan
Collaborators
National Eye Institute (NEI)
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1. Study Identification

Unique Protocol Identification Number
NCT03635645
Brief Title
Experimental and Clinical Studies of Retinal Stimulation
Official Title
Experimental and Clinical Studies of Retinal Stimulation
Study Type
Interventional

2. Study Status

Record Verification Date
December 2022
Overall Recruitment Status
Recruiting
Study Start Date
October 30, 2017 (Actual)
Primary Completion Date
October 30, 2023 (Anticipated)
Study Completion Date
October 30, 2023 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
University of Michigan
Collaborators
National Eye Institute (NEI)

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
Yes
Device Product Not Approved or Cleared by U.S. FDA
Yes

5. Study Description

Brief Summary
The study will evaluate new methods of retinal stimulation and training with the goal of improving the visual ability of retinal prosthesis participants.
Detailed Description
The study will test new ways to make the retinal prosthesis visual perception easier with auditory-visual training and how to make the retinal prosthesis work better at perceiving shapes.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Retinitis Pigmentosa

7. Study Design

Primary Purpose
Other
Study Phase
Not Applicable
Interventional Study Model
Single Group Assignment
Masking
None (Open Label)
Allocation
N/A
Enrollment
20 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Retinal stimulation
Arm Type
Experimental
Arm Description
Alternative stimulus patterns will be tested (vs. baseline). The intervention is the alternative stimulus pattern. The intervention will be tested only in the clinic vs. baseline. The subject will go home with baseline settings. The two alternative stimulus patterns to be tested are asymmetric waveforms and bipolar stimulus.
Intervention Type
Device
Intervention Name(s)
New visual processing unit (VPU) with asymmetric waveforms
Intervention Description
A VPU will apply asymmetric and symmetric stimulation pulses.
Intervention Type
Device
Intervention Name(s)
New VPU with bipolar stimulation
Intervention Description
A VPU will apply bipolar stimulus pulses.
Primary Outcome Measure Information:
Title
Percent change in stimulus thresholds
Description
Compare baseline threshold with threshold of modified stimulus parameters. Threshold is measured in microCoulumbs ( the product of stimulus duration and stimulus amplitude).
Time Frame
Baseline, 8 hours
Title
Change in shape perception
Description
As measured by elongation ratio. The elongation ratio is the ratio of major axis length to minor axis length of an ellipse. Subjects will draw shapes on a touch screen and these shapes will be fit to an ellipse.
Time Frame
Baseline, 8 hours

10. Eligibility

Sex
All
Minimum Age & Unit of Time
25 Years
Maximum Age & Unit of Time
89 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Must be implanted with an Argus II Retinal Prosthesis system. Have 5 or more electrodes that create a perception with stimulation. Must be willing and able to comply with the protocol testing requirements. Exclusion Criteria: Subjects participating in another investigatory drug or device study Any disease or condition that prevents understanding or communication of informed consent, study demands, and testing protocols.
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
James Weiland
Phone
661-713-4603
Email
weiland@umich.edu
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
James Weiland
Organizational Affiliation
University of Michigan
Official's Role
Principal Investigator
Facility Information:
Facility Name
University of Michigan
City
Ann Arbor
State/Province
Michigan
ZIP/Postal Code
48105
Country
United States
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
James Weiland
Phone
661-713-4603
Email
weiland@umich.edu

12. IPD Sharing Statement

Learn more about this trial

Experimental and Clinical Studies of Retinal Stimulation

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