How VRT can improve vision loss from a neurological origin.
As director of the Neuro-Optometric Rehabilitation Clinic at a New Jersey rehabilitation hospital, and after more than 30 years of private clinical experience treating people who have suffered stroke or brain injury, I have treated hundreds of people who have hemianopsia or hemispatial neglect.
Millions of people worldwide suffer from side vision loss due to neurological injuries like stroke, trauma, or resection of tumors in the brain. Most people with side vision loss are told that compensatory scanning in the direction of the field loss is the only recourse.
Loss of one half the visual field is termed hemianopsia. People who have a hemianopsia are usually aware of the side vision loss. Hemispatial neglect is the inattention to, or lack of awareness of, the loss of one half of the side vision. It is usually associated with a hemianopsia.
The lesion in the brain causing hemianopsia and/or hemispatial neglect usually occurs in the right frontal-parietal lobe, resulting in left side hemianopsia and/or left side hemispatial inattention.
Symptoms and Signs of Hemianopsia and Neglect
Symptoms and signs of hemianopsia and/or neglect may include:
- Cannot, or does not, readily or spontaneously scan into the area of the hemianopsia.
- No awareness of the field loss.
- Bumps into things on the side of the hemianopsia, but doesn’t learn to compensate for the problem.
- Misses parts of words on the side of the neglect, and/or misses parts of the eye chart line on the side of the neglect.
- Head or body orientation turned away from the neglected side.
- When ambulating, the patient may drift away from the neglected side.
Effective treatment of hemianopsia involves input from a variety of rehabilitation specialists — optometric physicians skilled in neuro-optometric rehabilitation, physiatrists, occupational therapists, physical therapists, and optometric vision therapists under the direction of an optometric physician. A three-prong rehabilitation protocol is recommended for reducing hemispatial neglect:
- Training compensatory eye movement scanning in the direction of the field loss and other visually related therapies.
- The prescription of side vision awareness glasses (SVAGs).
- A program of vision restoration therapy (VRT).
Basic Protocol for Treating Hemianopsia and Neglect
- My protocol for the initial visual treatment of hemianopsia and neglect is as follows:
- Encourage eye and head movements to the affected side, including scan board exercises.
- Teach the patient to use closed eye scanning movements as well as open eye scanning movements toward the affected side.
- Have the patient walk around the room in the direction of the affected side to reinforce the lack of a visual map of space on the neglected side.
- Have the patient use a flashlight aimed alternately toward each foot while walking, to enhance vision with visual-motor reinforcement on the affected side.
- Encourage games like crossword puzzles and real (hard copy) card games (not computer games), centered away from the midline toward the affected side.
- Increase sensory awareness on the affected side. Have the patient squeeze a ball using their hand on the side of neglect; trace a line that extends into the side of the defect; place the patients’ finger in the area of neglect, with the therapist rubbing the patient’s finger to stimulate sensory awareness on that side.
Tell the patient to forcibly/rapidly move their eyes as far toward the neglect as possible while sensing the feeling of their eyes at the extreme gaze. Encourage the patient to become aware of the “feel” of their eyes when gazing as far toward the neglected side as possible.
- To encourage scanning toward the hemianopsia, have the patient wear a “beeper-timer” wristwatch set to beep at intervals as a reminder to scan regularly toward the field deficit.
- When the patient begins to have awareness of their hemi-field loss, teach the patient to visually scan about 20 degrees toward the field loss, and then to turn the head in the direction of the field loss once they have scanned 20 degrees in that direction.
- Use therapies to stimulate physical movement into the area of neglect, such as balloon catching/tossing, and searching for predictive (and later non-predictive) stimuli in the neglected field.
- Turning a page at a 45-degree angle will improve reading ability for some patients with neglect who do not respond to other treatments.
- Enhancing the “blind sight” aspects of hemianopsia will allow a patient more spatial awareness (at a subconscious level) within their hemianopic field defect. Studies have shown that some patients can detect orientation of a vertical or horizontal line, discern the color of a green or red object, or point to the approximate location of a moving object held within the area of the field loss.