Parkinson's DiseaseDBS strabismusNCT06857851
Optimizing Deep Brain Stimulation to Improve Visuomotor Function in Parkinson's Disease
An observational study of Parkinson's Disease, run by VA Office of Research and Development at 1 site in United States.
Trial summary
Inability to align and refocus the eyes on the objects at different depths, i.e., vergence impairment and strabismus, frequently affects the quality of life in patients with Parkinson's disease. Read more about this study
- Who is it for?
- Any age
- Conditions the study is for
- Parkinson's Disease
- How many people
- 80 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Feb 2026to 1 Oct 2029
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages Any age
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: United States Military Veterans
Who may be able to join
- Parkinson's disease with bilateral STN DBS
- Availability of pre-operative MR images (with a T1-weighted, gradient-echo sequence) and ability to get post-operative MRI or CT scans
- Hoehn and Yahr stage 2-4 when off medication, and a stable antiparkinsonian medication regimen and DBS parameter settings
Who cannot join
- Previous surgical therapy for Parkinson's disease (other than DBS)
- Dementia
- Clinically significant untreated depression or anxiety
- Clinical features suggestive of atypical parkinsonism
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
Louis Stokes VA Medical Center, Cleveland, OH
Cleveland, Ohio, 44106-1702
Cheryl Dudek, 216-679-3800, cheryl.dudek@va.gov
Aasef G Shaikh, MD PhD, (216) 791-3800 ext. 60000, Aasef.Shaikh@va.gov
About this study
Inability to align and refocus the eyes on the objects at different depths, i.e., vergence impairment and strabismus, frequently affects the quality of life in patients with Parkinson's disease. The investigators study aims to understand the location-specific effects of subthalamic region deep brain stimulation on vergence and strabismus by integrating the patient-specific deep brain stimulation models and high-resolution eye-tracking measures. The knowledge gained will allow the investigators to find the most beneficial stimulation location and parameters for improving binocular coordination, strabismus, and vergence while preserving the ability to treat motor symptoms in Parkinson's disease.
Read the detailed description
The victims of very common condition Parkinson's disease (PD) are known to have tremor, rigidity, and slow movements. PD, in addition to its effects on human movements, also affects many other aspect of the brain's function. Impairment of vision is frequently seen in PD. These patients have difficulties with holding their eyes steady at a given point, seamlessly look around and read, and refocus their eyes from one image to the other while looking at objects that are at different depths. About third of the PD patients have problems coordinating the movement of two eyes together, i.e., abnormal vergence and strabismus. Latter results in disabling double vision and abnormal depth perception. Most treatment options available to PD patients are limited to their effects on tremor, stiffness, and slowness - their effects on visual function is very limited. Eye surgeries are not ideal treatment strategies for these conditions given constantly changing state of the PD brain due to its degenerative nature. Cutting edge deep brain stimulation (DBS) surgery has variable effects on the eye movements and vergence function and strabismus in PD. The goal of the investigators research program is to identify the best possible therapeutic strategy using DBS to improve vergence eye movements and strabismus in PD while continuing to offer its other benefits. The investigators multidisciplinary program has two aspects. One part of the study will examine the effects of DBS on vergence abnormalities and strabismus affecting their ability to focus at various depths. Using state of art, high-resolution, research grade ophthalmic equipment the investigators will examine fine details of how DBS alters the patients' ability to refocus and how it changes the alignment between the two eyes that can cause double vision and abnormal depth perception. Once the investigators identify these characteristic changes, the investigators will correlate them with the stimulated anatomical location within the same patient's brain determined using combination of novel computer simulations of DBS and the patient's own MRI. The knowledge gained will allow the investigators to find the ideal stimulation locations that is most beneficial to the patient for improvement in vision while continuing to offer benefits for tremor, rigidity, and slow movements.
- Conditions
- Parkinson's Disease
- Keywords
- Parkinson's disease, Deep brain stimulation, subthalamic nucleus
- Medical subject headings
- Parkinson Disease
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Parkinson's disease with DBS | This is the only group. The patients in this group will have bilateral subthalamic region deep brain stimulator. They will be recruited after they are therapeutically optimized on stimulation as well as medical therapy. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Eye alignment - vergence gain
The investigators will measure vergence gain as one outcome measure. This measure will be calculated by measuring ratio of observed versus expected difference between the horizontal angular positions of the right and left eye as participants move gaze from far to near or vice versa.
Measured: One month
Strabismus
The investigators will measure difference in position of right versus left eye as participants hold gaze on object of interest.
Measured: One month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Mar 2025
- Study start1 Feb 2026
- Primary completion30 Sep 2029 (estimated)
- Study completion1 Oct 2029 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Parkinson's DiseaseStudies of the same condition, open and under way.
- More trials run by VA Office of Research and DevelopmentThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 80 participants (estimated)
Sponsor and investigators
- Lead sponsor
- VA Office of Research and Development
- Sponsor type
- US federal agency
- Responsible party
- Sponsor
- Investigators
- Aasef G. Shaikh, MD PhD, Principal investigator, Louis Stokes VA Medical Center, Cleveland, OH
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06857851
- Sponsor's protocol ID
- C5298-R
- Other IDs
- I01RX005298-01A1
- Acronym
- DBS strabismus
- Status last verified
- Jul 2026
- First submitted
- 19 Feb 2025
- Last updated
- 7 Jul 2026
- Results posted
- No
- Data monitoring committee
- Yes
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 7 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Optimizing Deep Brain Stimulation to Improve Visuomotor Function in Parkinson's Disease
- ClinicalTrials.gov ID
- NCT06857851
- Acronym / sponsor ID
- DBS strabismus / C5298-R
- Conditions
- Parkinson's Disease
- Keywords
- Parkinson's disease, Deep brain stimulation, subthalamic nucleus
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 80 participants (estimated)
- Lead sponsor
- VA Office of Research and DevelopmentUS federal agency
- Study start
- 1 Feb 2026 (actual)
- Primary completion
- 30 Sep 2029 (estimated)
- Study completion
- 1 Oct 2029 (estimated)
- First posted
- 4 Mar 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Inability to align and refocus the eyes on the objects at different depths, i.e., vergence impairment and strabismus, frequently affects the quality of life in patients with Parkinson's disease. The investigators study aims to understand the location-specific effects of subthalamic region deep brain stimulation on vergence and strabismus by integrating the patient-specific deep brain stimulation models and high-resolution eye-tracking measures. The knowledge gained will allow the investigators to find the most beneficial stimulation location and parameters for improving binocular coordination, strabismus, and vergence while preserving the ability to treat motor symptoms in Parkinson's disease.
Detailed description
The victims of very common condition Parkinson's disease (PD) are known to have tremor, rigidity, and slow movements. PD, in addition to its effects on human movements, also affects many other aspect of the brain's function. Impairment of vision is frequently seen in PD. These patients have difficulties with holding their eyes steady at a given point, seamlessly look around and read, and refocus their eyes from one image to the other while looking at objects that are at different depths. About third of the PD patients have problems coordinating the movement of two eyes together, i.e., abnormal vergence and strabismus. Latter results in disabling double vision and abnormal depth perception. Most treatment options available to PD patients are limited to their effects on tremor, stiffness, and slowness - their effects on visual function is very limited. Eye surgeries are not ideal treatment strategies for these conditions given constantly changing state of the PD brain due to its degenerative nature. Cutting edge deep brain stimulation (DBS) surgery has variable effects on the eye movements and vergence function and strabismus in PD. The goal of the investigators research program is to identify the best possible therapeutic strategy using DBS to improve vergence eye movements and strabismus in PD while continuing to offer its other benefits. The investigators multidisciplinary program has two aspects. One part of the study will examine the effects of DBS on vergence abnormalities and strabismus affecting their ability to focus at various depths. Using state of art, high-resolution, research grade ophthalmic equipment the investigators will examine fine details of how DBS alters the patients' ability to refocus and how it changes the alignment between the two eyes that can cause double vision and abnormal depth perception. Once the investigators identify these characteristic changes, the investigators will correlate them with the stimulated anatomical location within the same patient's brain determined using combination of novel computer simulations of DBS and the patient's own MRI. The knowledge gained will allow the investigators to find the ideal stimulation locations that is most beneficial to the patient for improvement in vision while continuing to offer benefits for tremor, rigidity, and slow movements.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Parkinson's disease with DBS | – | –This is the only group. The patients in this group will have bilateral subthalamic region deep brain stimulator. They will be recruited after they are therapeutically optimized on stimulation as well as medical therapy. |
Who may qualify
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- United States Military Veterans
Key inclusion criteria (3 listed)
- Parkinson's disease with bilateral STN DBS
- Availability of pre-operative MR images (with a T1-weighted, gradient-echo sequence) and ability to get post-operative MRI or CT scans
- Hoehn and Yahr stage 2-4 when off medication, and a stable antiparkinsonian medication regimen and DBS parameter settings
Key exclusion criteria (4 listed)
- Previous surgical therapy for Parkinson's disease (other than DBS)
- Dementia
- Clinically significant untreated depression or anxiety
- Clinical features suggestive of atypical parkinsonism
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Eye alignment - vergence gain
Time frame: One month
The investigators will measure vergence gain as one outcome measure. This measure will be calculated by measuring ratio of observed versus expected difference between the horizontal angular positions of the right and left eye as participants move gaze from far to near or vice versa.
Strabismus
Time frame: One month
The investigators will measure difference in position of right versus left eye as participants hold gaze on object of interest.
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 7 Jul 2026.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Aasef G. Shaikh, MD PhD principal investigator
Louis Stokes VA Medical Center, Cleveland, OH
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Parkinson's Disease, run by VA Office of Research and Development at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 7 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Aasef G Shaikh, MD PhD ((216) 791-3800 ext. 60000, Aasef.Shaikh@va.gov), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Eye alignment - vergence gain (time frame: One month). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 7 Jul 2026.