Experimental and Clinical Studies of Retinal Stimulation

Not Applicable

Recruiting

• Conditions: Retinitis Pigmentosa
• Interventions: Device: New visual processing unit (VPU) with asymmetric waveforms; Device: New VPU with bipolar stimulation

• Registration Number: NCT03635645
• Lead Sponsor: University of Michigan

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.

Study Timeline

• Study Start: 2017-10-30
• Study First Submitted: 2018-07-26
• Study First Submitted QC: 2018-08-15
• Study First Posted: 2018-08-17
• Status Verified: 2022-12
• Last Update Submitted: 2022-12-12
• Last Update Posted: 2022-12-14
• Primary Completion: 2023-10-30
• Study Completion: 2023-10-30

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 20

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.

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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.

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Retinal stimulation	New VPU with bipolar stimulation	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.
Retinal stimulation	New visual processing unit (VPU) with asymmetric waveforms	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.

Primary Outcome Measures

Name	Time	Method
Percent change in stimulus thresholds	Baseline, 8 hours	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	Baseline, 8 hours	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.

Trial Locations

Locations (1)

University of Michigan; 🇺🇸 Ann Arbor, Michigan, United States