NCT03635645

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.

Trial Health

57
Monitor

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Trial has exceeded expected completion date
Enrollment
20

participants targeted

Target at below P25 for not_applicable

Timeline
Completed

Started Oct 2017

Longer than P75 for not_applicable

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

October 30, 2017

Completed
9 months until next milestone

First Submitted

Initial submission to the registry

July 26, 2018

Completed
22 days until next milestone

First Posted

Study publicly available on registry

August 17, 2018

Completed
5.2 years until next milestone

Primary Completion

Last participant's last visit for primary outcome

October 30, 2023

Completed
Same day until next milestone

Study Completion

Last participant's last visit for all outcomes

October 30, 2023

Completed
Last Updated

December 14, 2022

Status Verified

December 1, 2022

Enrollment Period

6 years

First QC Date

July 26, 2018

Last Update Submit

December 12, 2022

Conditions

Retinitis Pigmentosa

Outcome Measures

Primary Outcomes (2)

  • 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).

    Baseline, 8 hours

  • 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.

    Baseline, 8 hours

Study Arms (1)

Retinal stimulation

EXPERIMENTAL

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.

Device: New visual processing unit (VPU) with asymmetric waveformsDevice: New VPU with bipolar stimulation

Interventions

New visual processing unit (VPU) with asymmetric waveformsDEVICE

A VPU will apply asymmetric and symmetric stimulation pulses.

Retinal stimulation
New VPU with bipolar stimulationDEVICE

A VPU will apply bipolar stimulus pulses.

Retinal stimulation

Eligibility Criteria

Age25 Years - 89 Years
Sexall
Healthy VolunteersNo
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • 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.

You may not qualify if:

  • 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.

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

University of Michigan

Ann Arbor, Michigan, 48105, United States

RECRUITING

MeSH Terms

Conditions

Retinitis Pigmentosa

Condition Hierarchy (Ancestors)

Eye Diseases, HereditaryEye DiseasesRetinal DystrophiesRetinal DegenerationRetinal DiseasesGenetic Diseases, InbornCongenital, Hereditary, and Neonatal Diseases and Abnormalities

Study Officials

  • James Weiland

    University of Michigan

    PRINCIPAL INVESTIGATOR

Central Study Contacts

James Weiland

CONTACT

661-713-4603weiland@umich.edu

Study Design

Study Type
interventional
Phase
not applicable
Allocation
NA
Masking
NONE
Purpose
OTHER
Intervention Model
SINGLE GROUP
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor of Biomedical Engineering

Study Record Dates

First Submitted

July 26, 2018

First Posted

August 17, 2018

Study Start

October 30, 2017

Primary Completion

October 30, 2023

Study Completion

October 30, 2023

Last Updated

December 14, 2022

Record last verified: 2022-12

Locations

US(1)