ClinicalTrials.gg
Active, not recruitingNCT02747589Updated Jan 8, 2026

Feasibility of Stimulating the Visual Cortex in Blind

An interventional study of Surgical device implant in brain in Blindness,Acquired, sponsored by University of California, Los Angeles. Active, not recruiting at 1 site in United States. Open to participants aged 18 Years to 74 Years. Per ClinicalTrials.gov, last updated 2026-01-08.

Sponsored by University of California, Los Angeles · Not applicable, Interventional, and Basic science

Phase
Not applicable
Study type
Interventional
Enrollment
5
Allocation
Not applicable
Ages
18 Years to 74 Years
Sex
All
01

Study summary

In this study, the investigators intend to evaluate the use of a commercially available neurostimulator system, NeuroPace RNS System to stimulate the visual cortex. The NeuroPace RNS System has a proven record of safety and reliability was approved by the FDA in November 2013. The RNS System is indicated for use in patients with epilepsy and includes a skull implanted neurostimulator. No modification to the RNS System is required for this study. This study will use this device to better understand the effect of stimulation on the visual parts of the brain.

The main purposes of this study are to confirm the desired location to implant a device in the visual cortex, determine the amount of energy needed to elicit vision, and assess the nature of the vision that is produced. This information is important to have early in the process of designing a visual cortical prosthesis that could eventually be used for commercial use.

02

Conditions studied

  • Blindness,Acquired

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03

In context

Blindness

144 studies on the registry are indexed under Blindness; 33 are open to participants now.

This study's planned enrollment of 5 is below the median of 37 across 101 interventional studies indexed under Blindness.

Browse Blindness studies →

Lead sponsor

University of California, Los Angeles is the lead sponsor of 1,170 studies on the registry; 195 are open to participants now.

Of its 95 completed or terminated interventional studies of FDA-regulated products, 70 (74%) have results posted.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 74 Years
Sexes eligible
All
Accepts healthy volunteers
No

Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.

Inclusion criteria

  1. Subject is blind (i.e. bare light perception or no light perception in both eyes).
  2. Subject has a history of useful form vision.
  3. Subject is between the age of 18-74.
  4. Subject resides within 2 hours distance (by ground transportation) of the site.
  5. Subject is (a) male or (b) a female of with a negative pregnancy test who is using a reliable method of or is at least two years .
  6. Subject is able to complete regular office and telephone appointments per the protocol requirements.
  7. Subject is medically fit for neurosurgical intervention.
  8. Subject is considered a good candidate to be implanted with the investigational device.

Exclusion criteria

Exclusion Criteria:

  1. Subject is blind due to cortical etiology (e.g. injury to the visual cortex).
  2. Subject is eligible for another commercially available vision restoration therapy (e.g. retinal prosthesis).
  3. Subject is at high risk for surgical complications such as active systemic infection, coagulation disorders (such as the use of anti-thrombotic therapies) or count below 100,000.
  4. Subject has history of bleeding or immune compromise.
  5. Subject is taking chronic anticoagulants or antiplatelet agent or subject has an abnormally elevated preoperative coagulation profile (either or PT/INR).
  6. Subject has had prior craniotomy or brain surgery.
  7. Subject has evidence of active intracranial disease that would preclude elective neurosurgical intervention, such as unruptured intracranial aneurysm or brain tumor, or aberrant visual cortex anatomy, such as prior stroke or arteriovenous malformation.
  8. Subject has a significant abnormality on preoperative brain MRI
  9. Subject has a prior history of seizures or epilepsy.
  10. Subject has Parkinson's disease
  11. Subject has a prior history of serious head injury with loss of consciousness.
  12. Subject has a progressive central nervous system disease.
  13. Subject has history of implant-related infection.
  14. Implantation of the device would present unacceptable risk.
  15. Subject requires or is likely to require any of the following medical procedures while implanted with the NeuroPace RNS System: MR imaging, diathermy, electroconvulsive therapy (ECT), or transcranial magnetic stimulation (TMS). These medical procedures are for patients with an implanted RNS® System. Energy from these procedures can be sent through the implanted brain stimulation system and cause permanent brain damage which may cause severe injury, coma, or death. Brain damage can occur from any of the listed procedures even if the RNS® Neurostimulator is turned off or if the Leads are not connected to the Neurostimulator, and can occur even if the Neurostimulator has been removed and any Leads (or any part of a Lead) or the cranial prosthesis remain. Refer to the Contraindications section of the RNS System User Manual for further details.
  16. Subject is implanted with any neurostimulation or neuromodulation device in the head including, but not limited to cochlear implant, deep brain stimulator, or auditory brain implant.
  17. Subject has a or unstable medical condition including uncontrolled systemic hypertension with values above 170/100; cardiac or pulmonary disease; uncorrected coagulation abnormalities; diabetes; or any condition that would render the patient unable to safely cooperate with the study tests as judged by the screening physician.
  18. Subject has had an alcohol or illicit substance use disorder within the last 6 months, unstable remission of substance abuse, or chart evidence that co-morbid substance use disorder could account for lack of treatment response.
  19. Subject has uncontrolled chronic pain.
  20. Subject has significant neurocognitive impairment in memory domain (based on -BLIND \<18 or WAIS-IV \<80, described below).
  21. Subject had moderate or severe depression, as determined by a score of at least 17 on the HAMD.
  22. Subject has had a suicide attempt in the last two years, presence of a suicide plan (an answer of "Yes" to Question C4 in Section C-Suicidality of MINI International Neuropsychiatric Interview), or a "yes" answer to any one of the ten suicidal ideation and behavior questions on the C-SSRS.
  23. Subject has a disease or condition that prevents understanding or communication of , study demands, and testing protocols, including:

    1. Cognitive decline including diagnosed forms of dementia and/or progressive neurologic disease
    2. Psychiatric disease including diagnosed forms of depression
    3. Does not speak a principal language associated with the region
    4. Deafness or selective frequency hearing loss that prevents adequate communication with the researchers.
  24. Subject is pregnant or planning on becoming pregnant in the next year.
  25. Subject is enrolled in another therapeutic investigational drug or device trial
Terms in these criteria, in plain language(10)

Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.

Investigational drug or device

A drug or device being studied in a clinical trial.

It may be new, or already approved and being studied for another use, dose or form. Criteria often leave out people who took part in another study of one within a recent period, commonly 30 days or five half-lives.

Childbearing potential

Able to become pregnant: from the first period until menopause, unless permanently unable to through surgery (removal of the womb, or of both ovaries or both fallopian tubes).

Criteria for people of childbearing potential usually ask for a negative pregnancy test and for contraception during the study and for a time after it.

Contraception

Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.

Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.

Postmenopausal

Periods have stopped for good: usually no period for 12 months in a row without another medical reason, sometimes confirmed by a blood test (FSH).

Platelets

Blood cells that help blood clot. Too few raises the risk of bleeding and bruising. A usual adult range is about 150–400 × 10⁹/L (150,000–400,000 per µL); each lab has its own reference range.

INR, PT and aPTT (clotting tests)

Blood tests of how long blood takes to clot. The INR is the prothrombin time (PT) put on a common scale; about 1 is usual for someone not taking a blood thinner.

Criteria often make an exception for people on a blood thinner such as warfarin, whose INR is raised on purpose.

Contraindication

A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.

Clinically significant

Judged by the study doctor to matter for your health or for the study. It is a doctor’s decision, so ask the study team if you are unsure whether something counts.

MMSE and MoCA

Short tests of memory and thinking, each scored out of 30. Lower scores suggest more difficulty; criteria give a range, either to include people with memory problems or to leave them out.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Not applicable
Primary purpose
Basic science
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
5 participants (estimated)

Study arms

  • Experimental
    Treatment Group

    Subjects will be implanted to assess the feasibility of stimulating visual cortex to restore vision in blind volunteers.

    Procedure: Surgical device implant in brain

Interventions

  • ProcedureSurgical device implant in brain

    Neuropace RNS implant ove visual cortex

06

What researchers measure

Primary outcomes

  1. Stimulation level required to elicit visual phosphene

    Quantitative outcome. Direct brain stimulation to reproduce visual phenomena has not been done. There are no predesigned outcome measures. For this outcome measure, we will determine how much stimulation (in amps) is required to induce a perception of vision.

    Time frame: 6 months

  2. Characterization of stimulation-induced visions

    Descriptive outcome. Subjects will be asked to describe the type of visual perception that is induced by direct brain stimulation.

    Time frame: 6 months

  3. Spatial localization of stimulation to produce visual phenomena with direct cortical stimulation.

    Anatomic outcome. No predetermined outcome scale exists. We will assess patients and the sites of brain stimulation to determine which areas of the brain produce reliable visual phenomena when stimulated.

    Time frame: 6 months

07

Study locations

1 site
  • UCLA Department of Neurosurgery
    Los Angeles, California 90095, United States
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Timeline

Tracking since Sep 25, 2026
ElapsedEstimatedEstimated, not yet reachedSimilar studies: half by the dot; the band is the middle halfHalf of similar studies reached it by the dot; the band is the middle half, from a quarter to three quarters

Started Aug 2016 (actual). Primary completion is estimated for Dec 2026, 124 months after the start.

Of 36 interventional studies with no phase under Blindness, half reached primary completion within 57 months of starting (the median), counting those still running; a quarter within 19. This study's planned 124 months is above that.

How these figures are worked out, and which studies are left out of them.

Registered
Apr 14, 2016
First posted
Apr 22, 2016
StartActual
Aug 2016
Primary completionEst.
Dec 31, 2026
CompletionEst.
Dec 31, 2026
Last update
Jan 8, 2026
What these dates mean
Start.
When the first participant enrolled; while estimated, when the study expects to open to recruitment.
Primary completion.
When the last participant was examined or treated to collect data for the study's main question, its primary outcome. A study that stopped early gives the date its data collection stopped.
Completion.
When the last participant's last visit took place, for every outcome, secondary ones and side effects included: the end of the study. Often later than primary completion, sometimes the same day.
Actual and Est.
Actual means the registry says the date has happened. Est. (estimated) is a date the sponsor plans or expects. It can still move, and the sponsor is expected to change it to actual once it has passed.
No changes since tracking began. The registry record was last updated on Jan 8, 2026, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT02747589
Responsible party
Ausaf A. Bari, MD, PhD (Principal Investigator, University of California, Los Angeles) — Principal investigator
First posted
Apr 22, 2016
Start date
Aug 2016
Primary completion
Dec 31, 2026 (estimated)
Completion
Dec 31, 2026 (estimated)
Last update
Jan 8, 2026

Study contacts

Ausaf Bari, MPH
principal investigator · University of California, Los Angeles

Oversight

Data monitoring committee
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is active, not recruiting, as verified in Nov 2025. You cannot join it, but the record below documents what was studied.

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Discussion

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