Vision Training for Cortical Blindness

Overseen By Chrys Callan

Age: 18+

Sex: Any

Trial Phase: Academic

Sponsor: University of Rochester

Must not be taking: Neuroactive medications

Disqualifiers: Ocular disease, Brain injury, Drug abuse, others

No Placebo Group All trial participants will receive the active study treatment (no placebo)

Compensation: Varies

Number of Visits: Unknown

30 Participants Needed

Trial Summary

What is the purpose of this trial?

This project aims to develop a novel visual training paradigm for use in visually-intact participants and those sufferings from stroke-induced visual impairments. Our task design is built upon theories of statistical learning to reduce the overall training burden while still producing profound improvements to visual abilities. Efficacy will be first established in visually-intact controls before testing in stroke survivors to assess the feasibility of this form of learning in the damaged visual system.

Will I have to stop taking my current medications?

If you are currently taking neuroactive medications (drugs that affect the brain), you may need to stop, as these could impact the training. The decision will be made by the principal investigator (PI) of the study.

What data supports the effectiveness of the treatment Vision Training and Learning Task for cortical blindness?

Research shows that intensive training can help people with cortical blindness improve their ability to see motion in their blind field. Studies also suggest that systematic visual field training can restore visual functions in both adults and children with brain-related vision loss. ^{1 2 3 4 5}

Is vision training for cortical blindness safe for humans?

The research does not specifically address safety concerns, but it suggests that visual training can lead to improvements in vision for those with cortical blindness, indicating it may be safe for use in humans. ^{1 6 7 8 9}

How does the Vision Training and Learning Task treatment differ from other treatments for cortical blindness?

The Vision Training and Learning Task is unique because it uses visual training with both static and moving stimuli to help people with cortical blindness relearn visual discriminations beyond the limited abilities of blindsight. This approach is different from other treatments as it focuses on enhancing visual sensitivity and recovery through repeated stimulation and perceptual learning, even in cases of total cortical blindness. ^{1 7 9 10 11}

Eligibility Criteria

This trial is for individuals with vision loss due to stroke, including conditions like hemianopia and partial vision loss. It's open to those who have had either ischemic or hemorrhagic strokes that resulted in visual field defects. The study will first involve people without visual impairments before including stroke survivors.

Inclusion Criteria

Have successfully completed previous enrollment in Dr. Huxlin study (IRB #5966 or #75)

Reliable visual field defects in both eyes (homonymous defects) as measured by Humphrey visual fields. This deficit must be large enough to enclose a 5-deg diameter visual stimulus

Residents of the United States or Canada

Exclusion Criteria

History of traumatic brain injury

I am not on any brain-affecting meds that would interfere with the study.

Cognitive or seizure disorders

Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Visual Training

Participants undergo visual training based on statistical learning to improve visual abilities

8 weeks

Follow-up

Participants are monitored for safety and effectiveness after training

4 weeks

Treatment Details

Interventions

• Vision Training and Learning Task

Trial Overview The trial is testing a new type of visual training based on statistical learning theories. The goal is to improve vision with less training effort. Initially, the method will be tested on people with normal vision, then on those affected by stroke-related visual issues.

Participant Groups

Group I: Visual Training in Cortically Blind cohort Experimental Treatment 1 Intervention

Group II: Visual Training in Control cohort Experimental Treatment 1 Intervention

Who Is Running the Clinical Trial?

University of Rochester

Lead Sponsor

Trials

883

Recruited

555,000+

Findings from Research

In a study of 19 patients with visual field loss due to cerebral lesions, six months of Vision Restoration Training (VRT) significantly increased visual field size and improved cognitive functions, particularly attention.

The strongest predictor of visual field improvement was the size of areas of residual vision, while demographic and lesion-related factors had minimal impact on training success, suggesting that clinicians can use specific variables to predict training outcomes.

NCBI (Pubmed)

pubmed.ncbi.nlm.nih.gov

Multifactorial predictors and outcome variables of vision restoration training in patients with post-geniculate visual field loss. Poggel, DA., Mueller, I., Kasten, E., et al.[2008]

References

1. England pubmed.ncbi.nlm.nih.gov

Role of inter-hemispheric transfer in generating visual evoked potentials in V1-damaged brain hemispheres. [2018]

2. United States pubmed.ncbi.nlm.nih.gov

Visual and Motor Recovery After "Cognitive Therapeutic Exercises" in Cortical Blindness: A Case Study. [2018]

3. United States pubmed.ncbi.nlm.nih.gov

New approaches to visual rehabilitation for cortical blindness: outcomes and putative mechanisms. [2022]

4. Netherlands pubmed.ncbi.nlm.nih.gov

Multifactorial predictors and outcome variables of vision restoration training in patients with post-geniculate visual field loss. [2008]

5. England pubmed.ncbi.nlm.nih.gov

Restitution of visual functions in cerebrally blind children. [2013]

6. United States pubmed.ncbi.nlm.nih.gov

Functional MRI of Sensory Substitution in the Blind. [2021]

7. Poland pubmed.ncbi.nlm.nih.gov

Evidence for perceptual learning with repeated stimulation after partial and total cortical blindness. [2021]

8. Netherlands pubmed.ncbi.nlm.nih.gov

Rehabilitation of visual perception in cortical blindness. [2022]

9. United States pubmed.ncbi.nlm.nih.gov

Progressive atrophy in the optic pathway and visual cortex of early blind Chinese adults: A voxel-based morphometry magnetic resonance imaging study. [2022]

10. United States pubmed.ncbi.nlm.nih.gov

Beyond blindsight: properties of visual relearning in cortically blind fields. [2023]

11. England pubmed.ncbi.nlm.nih.gov

Rethinking the representation of sound. [2023]