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THE VISION THERAPY OPPORTUNITY

By Erich W. Mack

Release Date: November 1, 2013

Expiration Date: September 11, 2015

Learning Objectives:
Upon completion of this program, the participant should be able to:

  1. What types of conditions are helped by vision therapy
  2. What are the tools in a vision therapy practice
  3. What and how is brain plasticity shaping the future of vision therapy

Faculty/Editorial Board:
Erich W. MackErich W. Mack







Credit Statement:
This course is approved for one (1) hour of CE credit by the American Board of Opticianry (ABO). Course #SWJH534.


THE VISION THERAPY OPPORTUNITY

Most of us understand that vision is our keystone sense. It is the most relied on and integrated sense in human cognition. It plans and guides our effective movements, substitutes our need for touch to gather information, and is the foundation for imagination. The American Optometric Association states 80% of learning occurs through our eyes. Clearly good vision is crucial to all and especially so for young children.

As opticians, we generally describe our profession as one of identifying problems with vision and creating a plan for correcting it. Our usual course of consultative action falls in one of two categories; corrective lenses and medication.  But what if our vision fails or the diagnosis calls for something beyond refractive correction and medication? Many in our industry don't have broad knowledge of an effective third treatment category, called vision therapy. The American Optometric Association defines vision therapy as; "…a sequence of activities individually prescribed and monitored by the doctor to develop efficient visual skills and processing. It is prescribed after a comprehensive eye examination has been performed and has indicated that vision therapy is an appropriate treatment option.

The vision therapy program is based on the results of standardized tests, the needs of the patient, and the patient's signs and symptoms. The use of lenses, prisms, filters, occluders, specialized instruments, and computer programs is an integral part of the vision therapy." The Vision Council estimates 25% of school aged children suffer from undiagnosed vision problems. Two thirds of the problems are outside the scope of glasses. As a result, children with one or more undetected vision problems may have difficulties learning and thriving in life. In an eye opening study from a New York clinic, youth at risk of dropping out of school was found to have a 25% chance of being labeled and placed in special education. All of these children failed vision screening tests. Adults suffer from these same vision problems just as frequently and are also commonly undiagnosed. These conditions could have been present from birth or brought out later in life from stress, trauma, and disease to name a few. Study after study has shown a large population would benefit from vision therapy yet access and wide knowledge of vision therapy is restricted. Although recently plagued by controversy, vision therapy remains an effective and useful tool for a properly trained practitioner to treat a variety of special case patients and the future is as bright as ever.

THERE'S MORE TO VISION THAN MEETS THE EYE

To understand vision therapy it is important to have a functional definition of vision. Vision is the dominant sense and is composed of three areas of function. The first function is visual pathway integrity including eye health, visual acuity, and refractive status. The second function is visual skill including accommodation (eye focusing), binocular vision (eye teaming), and eye movements (eye tracking). The third function is visual information processing including identification, discrimination, spatial awareness, and integration with other senses.

Based on this understanding we can identify problems with our visual system. If we analyze the entire visual system there is information that enters the eye and is displayed on the retina. Outside of this are a muscle system and a neurological system. Problems with the latter two can cause inefficient vision and are the arena of vision therapy. Inefficient vision may cause an individual to slow down, be less accurate, experience excessive fatigue, or make errors. When these types of signs and symptoms appear, the individuals' conscious attention to the visual system is required. This, in turn, may interfere with speed, accuracy, and comprehension of visual tasks. Many of these visual dysfunctions are effectively treated with vision therapy.

Another important concept relating to the visual system is neuroplasticity and activity dependent plasticity. Neuroplasticity refers to changes in neural pathways and synapses, which are due to changes in behavior, environment and neural processes, as well as changes resulting from bodily injury. Activity dependent plasticity is the brain's ability to retain memories, improve motor function, and enhance speech and vision. To demonstrate this, a right-handed person may perform any movement poorly with his/her left hand but with continuous practice can be just as able with the left. The same concept works with vision as well. For example, amblyopic patients, stroke victims, brain cancer patients, and traumatic brain injury patients all can regain some or all vision loss using vision therapy and harnessing the power of brain plasticity. 

BUT GLASSES FIX VISION PROBLEMS, RIGHT?

Research has demonstrated vision therapy can be an effective treatment option for, ocular motility dysfunctions (eye movement disorders), Post Trauma Vision Disorder (traumatic brain injury), asthenopia (weakness or easy fatigue of the eye), non-strasbismic binocular disorders (inefficient eye teaming), strabismus (misalignment of the eyes), amblyopia (poorly developed vision), accommodative disorders (focusing problems).

Ocular motility dysfunction is defined as an impairment of eye movements as a primary manifestation of the disease. The dysfunction can be further divided into muscle, brain stem, and higher order sensory/motor systems. Ocular motility dysfunction can be observed by involuntary rapid eye movements and unusual head tilting, which can interfere with acquiring, fixating, and tracking visual stimuli. To demonstrate how this system works try the following experiment: Hold your hand up, about one foot in front of your nose. Keep your head still, and shake your hand from side to side, slowly at first, and then faster and faster. At first you will be able to see your fingers quite clearly. But as the frequency of shaking passes about 1 Hz, the fingers will become a blur. Now, keep your hand still and shake your head (up and down or left and right). No matter how fast you shake your head, the image of your fingers remains clear. This demonstrates that the brain can move the eyes opposite to head motion much better than it can follow, or pursue, a hand movement. When your pursuit system fails to keep up with the moving hand, images slip on the retina and you see a blurred hand. Patients with ocular motility dysfunctions commonly experience blurred vision and poor binocular function.

Amblyopia, or lazy-eye, is a disorder characterized by an impaired vision in an eye that otherwise appears normal. In many cases the affected eye is "turned off" by the brain due to a prolonged uncorrected strabismus or a large imbalance of visual acuity. Vision therapists more correctly describe Ambylopia as a visual cortex dysfunction rather than an eye dysfunction. The fact that once established, visual deficits often remain even after normal visual input has been restored using surgery supports this definition. Unfortunately many patients have been diagnosed too late and the Amblyopic eye is permanently "turned off". However, new research and clinical trials are showing hope for these patients using new vision therapy techniques. Early diagnosis in children and qualified treatment is very important for these patients.

Asthenopia is a weakness or easy fatigue of an eye characterized by pain, headache, blurred vision, and sometimes double vision. It is easily misdiagnosed as "dry eye" and can lead to an ineffective treatment plan. The underlying causes of Asthenopia are usually computer vision syndrome, convergence insufficiency, and vertical imbalance. Vision therapy is often successful in treating Asthenopia.

Traumatic brain injury or Post Trauma Vision Syndrome (which includes concussions) patients have, more recently, been found to be successfully treated by qualified vision therapists. Post Trauma Vision Syndrome is characterized by sensory problems after a traumatic brain injury, specifically blurred, double vision, and visual field defects. Blurred or double vision may improve during the first six months after the trauma event, but the field abnormalities are more likely to persist. The syndrome's symptoms are similar to those found in patients with traditional convergence insufficiencies and accommodation disorder, except in one fundamental way. Post Trauma Vision Syndrome patients' on-set is abrupt and the brain does not have the time to adapt (plasticity function). This sudden on-set leaves persistent symptoms and can lead to abnormal head posture. This happens because patients tilt or hold their head in an unnatural position to try and correct or improve visual function.

Convergence insufficiency is a common condition that is characterized by a patient's inability to maintain proper binocular alignment on objects as they approach from distance to near. The symptoms associated with convergence insufficiency vary from mild to severe; and are often extremely troublesome for patients with the condition. Patients with convergence insufficiency have a high success rate with vision therapy. Dramatic reduction of symptoms or even the disappearance of symptoms is common.

LET US CONVERGE FOR AWHILE

A successful vision therapy practice has many proven techniques and interesting tools (called orthoptics) at their disposal. These tools and techniques are used over an extensive period of time across varying therapy phases. Some of the most common are Brock strings (used for suppression/convergence insufficiencies), vectograms (training base in / base out ranges), loose lenses (training base in / base out ranges), random Dot Pads (training base in / base out ranges), eccentric circles (training base in / base out ranges), lens flippers (accommodation through refractive powers), prism flippers (accommodation through refractive powers).

Other techniques used are computer assisted home testing, Marsden Balls (develops hand-eye coordination and motor skills), rotational trainers (develops hand-eye coordination), and saccadic fixators (develops efficient eye tracking). Although many adolescents are traditionally thought of as vision therapy patients, age is not a deterrent to the achievement of successful vision therapy outcomes. Each patient doesn't necessarily require therapy using all the techniques, but usually a combination of them that are varied over time. The techniques are generally classed into one of two categories. First is Orthoptics, which has subsections of strabismic and non-strabismic.  The second category is called behavioral. Some patients will have therapy that has some overlap of both categories. The underlying purpose of many vision therapy sessions can be simple but can vary dramatically per patient. For example, one may need occulomotor strengthening which is very common, whereas another may require improved saccadic fixation (reading a series of sentences without any jumbling of the words or letters within the words).

Some patients benefit from yoked prisms to expand the field of vision or to correct posture and gait. Other patients desire an improvement in hand-eye coordination for occupational reasons (usually professional athletes). A typical vision therapy regimen may go as such. First, a patient has an initial exam to find diagnoses and develop a therapy plan. Usually the patient comes once a week for 16-20 weeks with periodic progress checks to measure improvement. Each session may last 30 minutes with one or more of the therapy tools. (i.e. vectograms, random dot, flippers etc…) A thirty minute limit on each session is important to maintain since significant eye fatigue usually occurs. The symptoms will usually be treated by the end of the 16-20 sessions but if more improvement can reasonably be expected with continued therapy, the doctor may extend the sessions. Brain scans are starting to elucidate more symptoms and syndromes that have traditionally been considered separate from the visual systems and are now known to be linked. It seems that in the future more diagnoses are going to be connected to the visual systems and thus remedied by vision therapy.

PLASTIC VISION

Activity dependent neuroplasticity is shaping the future of vision therapy. Amblyopia treatment is a shining example of this. When vision therapists approached Amblyopia as a visual cortex problem and used the principles of brain plasticity, the patient's recovered binocular vision and at any age! Their groundbreaking method uses special LCD goggles and measured contrast stimuli to establish just noticeable difference thresholds. When a binocular threshold limit was found, clinicians gradually began to balance each eye's limit. Towards the end of the therapy each eye had a very similar and functional threshold limit and thus binocular vision. The method is not a panacea; some patients with strabismus find it difficult to align contrast images but overall the treatment has been successful and has an exciting future. Dr. Quinlan and her rat lab demonstrated another important insight to Amblyopia and brain plasticity. She induced Amblyopia in rats by patching and measured their electrical brain activity. Noting the unusual brain activity she removed the occlusion and gave the rats time for visual recovery. No recovery was measured until she placed the rats in total darkness for 3-10 days. After the dark room exposure all the rats had a total neuropsychological recovery. The dark room exposure enhanced the neuroplasticity of the visual cortex.

Dr. Kaplan recently spoke about brain plasticity and the connection to myopia. Vision therapy wasn't directly related to the issue but his 14 years of research certainly supports the brain plasticity direction of treatment. His research, like rats in the dark, used human patients in an auditory void. He found that myopic patients refracted significantly less when no auditory stimulus was present and binocular vision broke down under auditory stimulus. Furthermore he noted, like the threshold contrast therapy, by fitting patients with maximum visual acuity minus lenses the brain tended to increase the myopic threshold and progress over time. He states this effect is contributing to the growing myopic epidemic.

A particularly interesting study about patients with ADHD and contrast response yielded unexpected results. Although no noticeable difference occurred for ADHD patients, a marked change was measure with clinically depressed patients. Depressed patients had a much slower response to contrast gain. The response became normalized when the depression lifted. This study gave more evidence that the visual system is affected by stressors outside the visual cortex and eyes, which suggests new ways of looking at therapy. Streff syndrome has been recommended for potential research using contrast gain response. Streff syndrome is characterized by a functional vision problem that involves poor eye focusing, eye teaming, and eye movements but from a purely psychogenic nature. Meaning the visual system is completely normal and should not have any of the symptoms; Streff Syndrome is purely psychologically based. The symptom is believed to be caused by stress and is already known to be successfully treated by vision therapy.

DIAGNOSIS, DOCTORS, CONTROVERSY

A recent report from Canada thoroughly examined the efficacy of vision therapy and found an apparent research war over its use. Optometrists stated adamantly that vision therapy was good practice; ophthalmologists were equally strong in their statements against it. Interestingly, vision therapy traces its origins back to an ophthalmologist from the late 19th century named Dr. Javal. He pioneered strabismus treatment with orthoptics and later his work was expanded by a Dr. Valk, another ophthalmologist, in 1904. Vision therapy continued to advance by the work of many ophthalmologist and optometrists until the late 1980's and early 1990's. During the period of the late 1960's to the 1990's, ophthalmologists' attitudes changed towards vision therapy and they began publishing papers opposing vision therapy. This change in attitude seems to be an aggregation of a failed perceptuo-motor remediation program called the Frostig Program which was a pseudo-vision therapy method carried out by educators, and a series of publications on behavioral vision therapy by optometrist Dr. Skeffington. The publication came into question when its postulations failed to meet the ophthalmologists' experimental design standards. Regardless, a recent survey by "Binocular Vision and Eye Muscle Surgery Quarterly" interviewing pediatric and stabismological ophthalmologists found that 64% of American doctors and 85% of international doctors recommend using vision therapy before surgery. The author speculated that there were three reasons for the differences between the views of U.S. and international ophthalmologists. They were:

  1. Insurance companies outside the U.S. do not compensate for eye muscle surgery as well as they do in the U.S.,
  2. U.S. surgeons do not get the same fee for orthoptic treatment as they do for surgery, and
  3. Surgeons may be reluctant to administer orthoptics and reluctant to send patients elsewhere to get treatment.

The fact that optometrists, ophthalmologists, and educators use different definitions for describing treatments and therapies continues to exacerbate the divide. Certainly there exist many criticisms of vision therapy. But to be clear, the majority of these criticisms arise from a lack of universal definition of disorders, defined experimental methods and methodology, and conflicting professional interests.

BREAKING THROUGH THE FOG

Controversy aside, vision therapy is a proven method and logical vanguard approach to patient care. As stated earlier, the necessity of universal definitions and agreed upon methodology is important groundwork that still has yet to be done. Until the time comes when that happens and doctors can put aside non-care related issues, most patients will not have a vision therapy option. Over one hundred years ago, Dr. Javal created the first vision therapy techniques and they have been advancing with more effectiveness and sophistication ever since. Modern brain imaging techniques are telling researchers that more and more disorders are linked to the visual system. With this new evidence it appears that once again vision therapy has a bright future.

NOTES

  1. Vision is our keystone sense (subhead: Vision Therapy Lives)
    1. 80% of learning occurs through eyes
    2. What if our vision fails / diagnosis calls from something other than glasses/CL/meds
    3. Vision therapy(VT) is the missing puzzle for certain patients
    4. Study after study show VT helps children as well as adults
    5. Thesis statement – Although recently plagues by controversy, VT remains an effective and useful tool for a properly trained practitioner to treat a variety of special case patients.
  2. To understand what VT is we must first have a function definition of what vision is (subhead: There's More to Vision than Meets the Eye)
    1. Vision is composed of three areas of function
      1. Visual pathway integrity
      2. Visual skills
      3. Visual information processing
    2. With this definition we can now identify problems with our visual system
      1. Visual systems and neurological problems are the arena of VT
    3. Another important concept to the visual system is neuroplasticity/activity dependent plasticity
      1. Right handed -> left handed person example
  3. Specific conditions that research has demonstrated VT is successful for (subhead: BUT GLASSES FIX VISION, RIGHT?)
    1. Ocular Motility dysfunctions
      1. Ocular motility dysfunction can be observed by involuntary rapid eye movements and unusual head tilting, which can interfere with acquiring, fixating, and tracking visual stimuli.
      2. Example: Hold your hand up, about one foot in front of your nose…
    2. Amblyopia
      1. Disorder characterized by an impaired vision in an eye that otherwise appears normal.
      2. Vision therapists more correctly describe Ambylopia as a visual cortex dysfunction rather than an eye dysfunction.
      3. Although new research and clinical trials are showing hope for these patients using new vision therapy techniques.
    3. Asthenopia
      1. Is a weakness or easy fatigue of an eye characterized by pain, headache, blurred vision, and sometimes double vision.
      2. It is easily misdiagnosed as "dry eye" and can lead to an ineffective treatment plan.
    4. Traumatic brain injury or Post Trauma Vision Syndrome
      1. is characterized by sensory problems after a traumatic brain injury, specifically blurred, double vision, and visual field defects
      2. Post Trauma Vision Syndrome patients' on-set is abrupt and the brain does not have the time to adapt
    5. Convergence insufficiency
      1. is characterized by a patient's inability to maintain proper binocular alignment on objects as they approach from distance to near
      2. Patients with convergence insufficiency have a high success rate with vision therapy
  4. Successful vision therapy practice has many proven techniques and interesting tools (subhead: LET US CONVERGE FOR AWHILE)
    1. Some of the most common are
      1. Brock Strings, vectograms, loose lenses, random dot, eccentric circles, lens flippers, prism flippers
    2. Each patient may vary in the tools/techniques used
    3. The goals for each patient may differ
      1. Occulomotor strengthening
      2. Saccadic fixation
      3. Yoked prism
      4. Hand-eye coordination
    4. Initial visit with doctor determines VT plan
      1. 16-20 weekly session
      2. 30min sessions max
  5. Activity dependent neuroplasticity is shaping the future of vision therapy(subhead: PLASTIC VISION)
    1. When vision therapists approached Amblyopia as a visual cortex problem and used the principles of brain plasticity, the patient's recovered binocular vision and at any age
    2. Another important insight to Amblyopia and brain plasticity was demonstrated by Dr. Quinlan and her rat lab
    3. Dr. Kaplan recently spoke about brain plasticity and the connection to myopia
    4. Streff syndrome has been recommended for potential research
  6. The efficacy of vision therapy and an apparent research war over its use (subhead: DIAGNOSIS, DOCTORS, CONTROVERSY)
    1. Optometrists stated adamantly that vision therapy was good practice; ophthalmologists were equally strong in their statements against it
    2. Vision therapy traces its origins back to an ophthalmologist from the late 19th century named Dr. Javal
    3. During the period of the late 1960's to the 1990's, ophthalmologists' attitudes changed towards vision therapy and they began publishing papers opposing vision therapy
      1. This change in is an aggregation of the failed Frostig Program, and a series of publications on behavioral vision therapy by optometrist Dr. Skeffington
    4. Regardless, pediatric and stabismological ophthalmologists report that 64% of American doctors and 85% of international doctors recommend using vision therapy before surgery
    5. Speculated that there were three reasons for the differences between the views of U.S. and international ophthalmologists
      1. Insurance reimbursements, fear of losing to patients to outside doctors, higher profits if surgery is performed
  7. Vision therapy is a proven method and logical vanguard approach to patient care (subhead: BREAKING THROUGH THE FOG)
    1. Necessity of universal definitions and agreed upon methodology is important groundwork
    2. Dr. Javal created the first vision therapy techniques and they have been advancing with more effectiveness and sophistication ever since
    3. Modern brain imaging techniques are telling researchers that more and more disorders are linked to the visual system
    4. With this new evidence it appears that once again vision therapy has a bright future