How treating a visual dysfunction may help patients who have headaches, dizziness, coordination and a host of other symptomsIn 1995, my brother-in-law, Dr. Arthur Rosner, an ENT surgeon, called with an interesting request: Evaluate his patients who experienced dizziness without a vestibular cause. [Ten years earlier, I had diagnosed Dr. Rosner as having a vertical heterophoria (VH). I had treated him with prism lenses, which helped his balance, coordination and reading difficulties.] I told him that, while O.D.s were not trained to use lenses to treat dizziness, I would be happy to try to evaluate just a few patients.
Some of Dr. Rosner’s patients presented using canes or carried nausea bags. Where my evaluation found VH, I treated the patients with standard prism lenses. During the trial framing process, however, it became clear that smaller units of prism were needed — where one lens was not strong enough, the next increment was too powerful. This led to the concept of an in-between, or “microprism” lens in increments of 0.25D. These microprism lenses markedly reduced or eliminated the patients’ symptoms.
Since that day, my colleagues and I have treated medical symptoms, such as dizziness, anxiety and headache, by identifying and correcting, with microprism lenses, the subtle underlying heterophoria (most frequently vertical) in more than 10,000 patients.
In addition to providing a significant patient service, I have found this type of neuro-optometric care addresses many challenges, including decreasing reimbursements for vision insurance and greater levels of competition from both brick and mortar and online eyewear sellers. To help educate other independent optometrists on the patient care and practice benefits of managing VH, I developed the NeuroVisual Medicine Training Program, and to date I have trained over 30 optometrists in the United States and Australia.
Here, I provide background on VH and explain how we manage patients who suffer from this dysfunction.
BackgroundVH, a type of binocular vision dysfunction, is a vertical misalignment of the eyes that can occur at any age. The two main causes are brain injury, such as concussion/traumatic brain injury or stroke, and congenital causes, such as vertical orbital asymmetry, or asymmetric extraocular muscle (EOM) innervation or strength. It is estimated that VH affects at least 10% of the U.S. population (33 million), according to a March 2012 article in Strabismus (“Vertical Heterophoria and Susceptibility to Visually-induced Motion Sickness” by Danielle Jackson and Harold Bedell, Ph.D.).
Table 1. Symptoms of Symptoms of Binocular Vision Dysfunction
When you have Binocular Vision Dysfunction, the list of possible symptoms can feel endless. Some people experience a handful of symptoms, while for others it’s more like fistfuls, completely disrupting their lives and resulting in disability. Symptoms can include:
→ Eye pain and / or pain with eye movements
→ Headaches or head pain / pressure
→ Aching face / “Sinus” pain
→ Fatigue with reading
→ Difficulty with reading comprehension (rereading for comprehension)
→ Difficulty concentrating
→ Skipping lines
→ Using a line guide (ruler, finger, envelope) to help keep your place
→ Words running together
→ Letters vibrating or shimmering
→ Head tilt, causing neck aches, upper back and shoulder pain
→ Drift to one side while walking
Inner Ear Symptoms
→ Dizziness / Lightheadedness
→ Unsteadiness with walking
→ Motion sickness (usually the first symptom, beginning in childhood)
→ Lack of coordination
→ Frequent falling
→ Difficulty walking down the grocery aisle
→ Trouble stopping in time due to difficulty estimating distances
→ Anxiety while driving, particularly on the freeway
→ Generalized anxiety
→ Feeling overwhelmed or anxious in crowds, large contained space with tall ceilings
→ Panic attacks
→ Suicidal thoughts
Binocular Vision Symptoms
→ Blurred / shadowed / overlapping / doubled-vision
→ Light sensitivity
→ Difficulty with glare or reflection
→ Closing / Covering one eye eases visual tasks
→ Poor depth perception / Difficulty with hand-eye coordination
→ Difficulty maintaining eye contact in conversations
Routine Visual Symptoms
→ Blurred vision at near or far distances
→ Difficulty with close-up vision (reading or computer use)
→ Difficulty with night vision
→ Eye strain and sore eyes
→ Fitful and restless sleep
→ Difficulty sleeping unless the room is completely dark
Table 2. Differential Diagnoses of Vertical Heterophoria
It’s common for people to have been diagnosed with a myriad of other conditions, then find out that Binocular Vision Dysfunction was the true culprit. These other conditions include:
→ ADD / ADHD
→ Anxiety / Panic disorders
→ Persistent Post-Concussive symptoms
→ Cervical misalignment
→ Meniere’s Disease
→ BPPV (Benign Paroxysmal Positional Vertigo)
→ Psychogenic dizziness / Chronic Subjective Dizziness
→ PPPD (Persistent Postural-Perceptual Dizziness)
→ Vestibular Migraine / Migraine Associated Vertigo (MAV)
→ MS (Multiple Sclerosis)
→ Reading and learning disabilities
→ Sinus problems
→ TMJ disorders
Identifying patientsBecause the symptoms of VH are not usually considered to be visually based, patients who experience heterophoria symptoms are routinely first evaluated by medical subspecialists, not an eye care professional. As a result, my referrals come from a diverse set of providers who have learned that our practice may provide symptomatic relief for those who have not responded to traditional treatment approaches (see Figure 1). They use three methods to identify those who might benefit from a NeuroVisual evaluation: the Binocular Vision Dysfunction Questionnaire (BVDQ), the 5 Minute Cover Test and the Near Point of Discomfort (NPD) test. While our colleagues use these screening tests as needed/indicated, we recommend that eye care professionals screen all patients presenting for their annual eye exam with these tests. If the results indicate a problem, we recommend the patient should return for a full neurovisual evaluation or be referred to an optometrist trained to provide this care.
The BVDQ is a 25-question survey instrument that queries about the frequency of BVD/VH symptoms from all the major symptom categories. (Click here to view a copy of the adult questionnaire or here to go to a live interactive version.) A score of > 15 indicates a high likelihood of binocular vision dysfunction, meriting the need for further evaluation.
In the 5 Minute Cover Test, the patient covers the eye that is physically higher for five minutes. (Click here to view the patient education document for the 5 Minute Cover Test or (here to view a video version of the instructions). If the patient notes a significant decrease in symptoms (the average reduction is between 33%-50% for patients who have VH), the patient most likely has a binocular vision problem and could benefit from a neurovisual evaluation. In our experience, about 80% of those with VH will respond favorably to this test. Those who have VH but do not respond most likely have significant baseline refractive abnormalities, such as astigmatism, hyperopia and myopia.
The NPD test is similar to the familiar Near Point of Convergence (NPC) test, except our endpoint is not diplopia but discomfort or exacerbation of the patient’s symptoms (particularly nausea, dizziness and pain) as the fixation object approaches the nose.
Diagnosis and TreatmentThe first step in the diagnosis of VH is to take a thorough medical history (including the BVDQ), which may uncover the symptoms mentioned above. Physical findings associated with VH include head tilt, vertical orbital asymmetry, a unilateral furrowed brow, leaning to one side when walking, unsteady gait, abnormal near point of discomfort testing and an abnormal 5 Minute Cover Test.
We also perform several sensorimotor tests utilizing a Maddox rod and red lens, which, taken together as a group, are able to guide our decision making. We identify the subtle misalignments and determine the amount of vertical prism needed by introducing small incremental units (0.25D) of vertical prism to a trial frame that contains the patient’s refractive prescription, a technique known as Prism Challenge. The correct vertical alignment is achieved when the patient experiences a marked reduction or elimination of VH symptoms coupled with maximization of their visual clarity. This occurs in about 95% of these patients.
The first prescription that contains microprism, however, is almost never the last prescription, as the tense extraocular muscles cannot relax quickly enough to allow the patient to wear the full amount of prism correction immediately. A second appointment is scheduled for two to four weeks after dispensing the initial glasses, at which time progressive relaxation of the EOM’s has occurred, with almost all patients accepting their final prescription adjustment at that time.
I have found that addressing the VH with the appropriate microprism lenses results in a reduction of symptoms by about 30%-50% within minutes. By the end of the treatment protocol, which usually is completed in two visits, the average patient experiences an 80% improvement, according to our research, which was published in the February 2016 issue of Brain Injury. (Microprism lenses can also lead to an improvement in visual-motor skills as shown in Figure 2.)
Patient EducationIn educating the patient, I explain that “normal” 20/20 means each eye can see clearly but does not address how the eyes work together as a team. We educate the patient that abnormal binocular vision manifests with the eyes struggling to work together as a team, with the resulting stresses and tension and visual discoordination causing the symptoms of VH.
Patients are often skeptical that a pair of “fancy glasses” can help relieve symptoms. However, having the patient experience significant symptom reduction (during trial framing, or when becoming monocular during the 5 Minute Cover Test) helps the patient understand the benefits.
In our experience, the capture rate for microprism glasses is 80%, with second pair sales about 35%. The high capture rate is likely due to the fact that the lenses contain microprism and require exacting manufacturing accuracy, so they cannot be purchased through online sellers.