Visual Restoration for Hemianopia

Study Overview
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Brief Summary
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The purpose of this research is to assess the efficacy of a visual training task on reducing the size of a visual field deficit caused by brain damage in adults, and its ability to improve visual functions in this patient population.

Official Title
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Visual Restoration for Hemianopia

Conditions
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Stroke Induced Vision Loss, Hemianopia, Quadrantanopia

Intervention / Treatment
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* Device: Training in the blind field
* Device: Training in the intact field


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Ages 21-75 years old Ability and willingness to sign informed consent Willingness to participate in both the training and evaluation sessions MRI or CT scan demonstrating lesion in the occipital lobe of the brain and/or affecting white matter tracts that provide visual input to the occipital lobe of the brain Brain injury due to ischemic or hemorrhagic causes that occurs after age 18 and at least 90 days prior to screening visit At least two reliable HVF's demonstrating good fixation and a stable homonymous incomplete (e.g., quadrantanopia or relative defect) or complete hemianopia Reliable HVFs with repeat HVFs if randomization takes place more than 4 weeks after screening visit A homonymous, contiguous visual deficit measured by the 24-2 HVF to be a minimum of two testing locations high and two testing locations wide, where impaired locations are any that measure a threshold of less than 15 dB. Demonstration of good fixation on visual training task - able to fixate the small targets presented as fixation letters reliably for 1000ms with jitter over less than 1 degree of visual angle in any direction away from target edge Exclusion Criteria: Physical, neurological or mental disability that would interfere with study intervention Concurrent participation in vision therapy other than standard occupational or physical therapy Unreliable visual fields on prior testing, indicated by greater than 20% fixation losses, false positives, or false negatives. Inability to discontinue medications judged to affect training and/or assessment (e.g., Ritalin, amphetamines, dopamines, or chemotherapeutic agents) Physical condition likely to preclude completion of the clinical trial (e.g. end-stage or uncontrolled cancer, uncontrolled epilepsy, or end-stage heart disease) Ocular or neurological condition that would interfere with training or assessment (e.g. damage to the optic nerves or lateral geniculate nucleus, any degenerative ocular condition) Best corrected vision worse than 20/40 Impaired foveal Humphrey sensitivity as indicated by the HVF tests. Presence of vision loss resulting from ocular disease or disorder Presence of bilateral visual acuity loss from any source Inability to demonstrate fixation stability on eye movement monitored testing Inability to follow training instructions

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Training in the blind field<br>Training in the blind field using software | Device: Training in the blind field<br>* A computer software and chin-rest necessary to perform visual training will be loaned to each patient to use at home. They will perform one to two daily training sessions in their home, consisting of 200-300 trials each. The visual task performed repetitively will involve discriminating the direction of motion of a small cloud of dots located at a pre-determined location in the blind field. The computer program will automatically create a record of patient performance during each home training session. They will train daily (about 40-60 minutes total), 5 to 7 days per week, for at least 24 weeks.<br>|
| Experimental: Training in the intact field<br>Training in the intact field using software | Device: Training in the intact field<br>* A computer software and chin-rest necessary to perform visual training will be loaned to each patient to use at home. They will perform one to two daily training sessions in their home, consisting of 200-300 trials each. The visual task performed repetitively will involve discriminating the direction of motion of a small cloud of dots located at a pre-determined location in the intact field of vision. The computer program will automatically create a record of patient performance during each home training session. They will train daily (about 40-60 minutes total), 5 to 7 days per week, for at least 24 weeks.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| 24-2 Humphrey PMD Change From Baseline to 6-month Post-training Timepoint | Change in the perimetric mean deviation (PMD) generated by standard Humphrey automated perimetry using a 24-2 testing pattern between baseline and post-training after a 6-month training interval. | 6 months |