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BVD Research

Welcome to our research section, where we explore the latest advancements and studies in eye care and vision health. Our focus spans a broad spectrum of topics, from innovative treatments for common vision disorders to the intricate connections between eye health and overall well-being. We are committed to deepening our understanding of how vision impacts our lives and finding new ways to enhance eye care. Join us in this journey of discovery as we delve into various studies and findings that are shaping the future of optometry and vision science.

Case Report: Successful resolution of four POTS cases using retinal neuromodulation for non-invasive assessment and treatment of autonomic function

POTS, dysautonomia

The document is a case report titled "Successful resolution of four POTS cases using retinal neuromodulation for non-invasive assessment and treatment of autonomic function" by Deborah Zelinsky O.D. and Clark Elliott Ph.D. It discusses the use of neuro-optometric techniques in the treatment of Positional Orthostatic Tachycardia Syndrome (POTS).

Key Points:

POTS Overview: POTS, a form of dysautonomia, presents challenges in cerebrovascular autoregulation. Traditional treatments focus on symptom management without resolving the underlying issue.

Retinal Neuromodulation: The authors propose a novel approach using retinal neuromodulation, where custom-designed eyeglasses alter phototransduction in the retina. This affects neural pathways related to POTS, potentially rebalancing the autonomic and central nervous systems.

Four Case Studies: The paper presents four case studies where patients with POTS experienced significant improvements after using these custom eyeglasses. These patients had symptoms unresponsive to traditional treatments.

Mechanism: The treatment involves stimulating the retina to influence signaling in both the autonomic and central nervous systems. This is based on the understanding that the retina is an extension of the brain and processes both visual and non-image-forming signals.

Neuro-Optometric Testing: Patients underwent neuro-optometric tests to assess their retinal tolerance and determine the appropriate eyeglass prescription. This included various lenses, prisms, and filters to balance incoming signals.

Outcomes: All four patients reported a cessation of syncope episodes and other related symptoms, suggesting a potentially permanent resolution of their condition.

Broader Implications: This approach implies that neuro-optometry can play a crucial role in treating autonomic function disorders and other neurological conditions, moving beyond traditional eyesight-focused optometry.

Conclusion: The authors suggest that measuring tolerance to retinal load is a vital step in managing autonomic function disorders. The case studies demonstrate the potential of neurodevelopmental optometric techniques in diagnosing and treating conditions like POTS.

The report emphasizes the importance of considering the retina's role in neurological conditions and the potential of non-invasive, neuro-optometric interventions in treating disorders traditionally considered intractable.

Eye Movement Abnormalities in Major Depressive Disorder

oculomotor dysfunction, eye movement abnormalities, major depressive disorder, depression

Main points of the article "Eye Movement Abnormalities in Major Depressive Disorder":

1. Major Depressive Disorder (MDD) is difficult to diagnose, and there is a need for biomarkers for its diagnosis.

2. Eye movements are considered potential non-invasive biomarkers for psychiatric disorders like schizophrenia.

3. The study evaluated detailed eye movement measurements of 37 MDD patients and 400 healthy controls.

4. Three eye movement tests were conducted: free-viewing, fixation stability, and smooth pursuit tests.

5. Significant differences were found in eye movement measurements between MDD patients and healthy controls.

6. In the free-viewing test, scanpath length was significantly shorter in MDD patients.

7. In the smooth pursuit test, duration of saccades and peak saccade velocity were significantly different in MDD patients.

8. There were significant group differences in older subjects for certain eye movement measurements.

9. A discriminant analysis using eye movement data showed MDD could be distinguished from healthy controls with 72.1% accuracy.

10. The study suggests that detailed eye movement tests can assist in differentiating MDD from healthy controls, especially in older individuals.

Clinical and oculographic response to Dexedrine in a patient with rod-cone dystrophy, exotropia, and congenital aperiodic alternating nystagmus

exotropia, alternating nystagmus, rod-cone dystrophy

The stimulant Dexedrine had a "paradoxical" positive effect on nystagmus, binocular function, and visual acuity in this patient with retinal dystrophy and congenital nystagmus. This observation suggests the potential for exploring new pharmacological treatment approaches for patients with congenital nystagmus or strabismus.

Neuro-Visual and Vestibular Manifestations of Concussion and Mild TBI

tbi, traumatic brain injury, concussion

1. Concussion, or mild traumatic brain injury, is a significant cause of disability.
2. Vestibular and visual dysfunction often occur following a concussion, negatively impacting patients' well-being and recovery.
3. Various factors can contribute to these symptoms, including ocular, neuro-ophthalmic, otologic, and neuro-vestibular conditions.
4. Some of these conditions are benign and treatable, while others can be vision or life-threatening, underscoring the importance of a focused history and examination.
5. The article discusses an approach to evaluating and treating common neuro-visual and vestibular impairments resulting from concussion.
6. Recent findings suggest promising treatment approaches for concussion, including exercise, computerized programs, transcranial magnetic stimulation, gene therapy, stem cell therapy, and nanoparticles.
7. While many novel therapies are being explored, therapy and evaluation for co-existing diseases remain fundamental in concussion management.

Vision in children with autism spectrum disorder: a critical review

autism spectrum disorder

- The article discusses vision in children with autism spectrum disorder (ASD).
- ASD has a prevalence of approximately 1-2% in the population and has lifelong effects.
- Early intervention and management are crucial for maximizing the quality of life and outcomes for individuals with ASD.
- Studies have attempted to link behavioral and sensory deficits in ASD with underlying visual processing.
- Individuals with ASD process the world differently, but there are gaps in our understanding.
- The article summarizes current knowledge about key aspects of visual functions and the optometric profile of ASD.
- Key findings include normal visual acuity, atypical eye movements, susceptibility for visuo-motor deficits, increased prevalence of strabismus, increased likelihood of astigmatism and possibly other refractive errors, attention, crowding, and task complexity issues, and possible compromises in retinal structure and function.
- The article emphasizes the need for further research to understand how higher-level functions relate to behaviors and to fully grasp the profile of visual processing in ASD.
- Comprehensive vision care is highlighted as beneficial for children with ASD.

Vision therapy: Occlusion, prisms, filters, and vestibular exercises for mild traumatic brain injury

traumatic brain injury, concussion, tbi

1. The article discusses various treatment approaches for visual complaints following mild traumatic brain injury (TBI).

2. These approaches include binasal occlusion, yoked prisms, vertical prisms, filters, and vestibular training.

3. Binasal occlusion is suggested for visual motion sensitivity, but its effectiveness is not well-supported by evidence.

4. Base-in prisms may help with convergence insufficiency, but there is limited data on their efficacy.

5. The concept of midline shift and the use of yoked prisms for its treatment in mild TBI cases are questionable and lack strong evidence.

6. Vertical heterophoria and the use of vertical prisms for mild TBI symptoms also lack controlled data and evidence.

7. Filters could potentially alleviate light intolerance, but studies supporting their effectiveness are lacking.

8. Better evidence is emerging for the benefits of vestibular therapy, with some randomized controlled trials providing support.

9. Overall, many of these techniques lack substantial evidence and should be considered unproven and, in some cases, implausible for treating mild traumatic brain injury symptoms.

Connective tissues reflect different mechanisms of strabismus over the life span


1. The article discusses the role of connective tissue pulleys in determining extraocular muscle force directions and how pulley abnormalities can lead to strabismus (eye misalignment).

2. Magnetic resonance imaging (MRI) was used to study 95 patients with pulley heterotopy, including 56 with childhood-onset pattern strabismus, and compared to 28 patients with sagging eye syndrome and age-matched control subjects.

3. Childhood-onset strabismus was associated with A or V pattern strabismus and abnormal rectus pulley positions, likely congenital in origin.

4. Surgical correction for childhood-onset pulley heterotopy often required transpositions of rectus muscles but could induce adverse torsion.

5. Adult-onset pulley heterotopy in sagging eye syndrome was characterized by external signs of adnexal laxity, including blepharoptosis and superior lid sulcus defects, and was linked to age-related connective tissue degeneration.

6. MRI findings showed significant lateral and inferior displacement of rectus pulleys in sagging eye syndrome, as well as tilting of the lateral rectus muscle.

7. The article highlights the importance of understanding pulley abnormalities in the etiology and treatment of strabismus, both in childhood and adult-onset cases.

Prism use in adult diplopia

diplopia, skew deviation, fourth nerve palsy, thyroid eye disease, orbital blowout fracture

- Approximately 80% of all adult patients with diplopia are satisfied with prismatic correction.
- Patients with vertical diplopia, specifically skew deviation and fourth nerve palsy, have high satisfaction rates of 100% and 92%.
- Patients with thyroid eye disease and orbital blowout fractures associated with diplopia have low satisfaction rates of 55% and 8%, respectively.
- For horizontal deviations, patients with decompensated childhood strabismus with a combination of horizontal and vertical deviations and patients with convergence insufficiency have low satisfaction rates of 71% and 50%, respectively.
- Careful patient selection, managing expectations, and continued follow-up are critical for the successful use of prisms in treating adult diplopia.

Visual disorders and mal de debarquement syndrome: a potential comorbidity questionnaire-based study

mal de debarquement syndrome, vertical heterophoria, balance disorder, traumatic brain injury, tbi

Summary of the article "Visual Disorders and Mal de Debarquement Syndrome: A Potential Comorbidity Questionnaire-Based Study":

1. The study explores the potential overlap of visual symptoms with Mal de Debarquement Syndrome (MdDS), a neurological condition characterized by a constant sensation of self-motion.
2. The MdDS group demonstrated higher visual disorder scores and visual complaints compared to controls.
3. There are two subtypes of MdDS: motion-triggered (MT) and non-motion-triggered/spontaneous (NMT/SO). NMT/SO participants reported unique visual symptoms and a higher prevalence of mild traumatic brain injury.
4. The findings suggest that visual disorders may coexist with MdDS, particularly in the NMT/SO subtype.
5. The differences in visual dysfunction frequency and medical histories between subtypes warrant further investigation into differing pathophysiological mechanisms.

Keywords: balance disorder, binocular vision dysfunction, Mal de Debarquement Syndrome (MdDS), mild traumatic brain injuries, vertical heterophoria, vestibular disorders, visual-induced dizziness.

Identification of binocular vision dysfunction (vertical heterophoria) in traumatic brain injury patients and effects of individualized prismatic spectacle lenses in the treatment of postconcussive symptoms: a retrospective analysis

vertical heterophoria, tbi, traumatic brain injury, concussion

The study identified vertical heterophoria in a group of TBI patients with postconcussive symptoms. The treatment of vertical heterophoria with individualized prismatic spectacle lenses resulted in a significant reduction in subjective symptom burden and a relative reduction in VHS-Q score. It suggested that vertical heterophoria can be acquired as a result of traumatic brain injury.

The Effects of Sports Vision Training on Binocular Vision Function in Female University Athletes

sports vision training

- The article discusses the effects of sports vision training on binocular vision function in female university athletes.
- The study involved 24 female student athletes from team ball sports like soccer, basketball, and handball.
- The athletes underwent an eye training program consisting of 20-minute sessions, three times a week for eight weeks.
- Optometric investigations were performed before the experiment, after the eight-week training, and four weeks after the training.
- The most common binocular vision disorder observed was exophoria, and low fusional vergence range was also noted.
- Following the training, three out of six oculomotor variables improved significantly, with the greatest improvement in near dissociated phoria and fusional convergence.
- The retention test conducted four weeks after the experiment confirmed the effectiveness of the vision training program.
- The study suggests that binocular functions are trainable and can be improved through appropriate visual training.

Treatment of vestibular disorders with weak asymmetric base-in prisms: An hypothesis with a focus on Ménière’s disease

vestibular dysfunction, meniere's disease

1. Ménière's disease (MD) is a vestibular disorder characterized by vertigo, sensorineural hearing loss, and fluctuating aural symptoms.

2. Traditional treatments for MD include pharmacotherapy, physical therapy, intratympanic pharmacotherapy, and surgery, but there is no definitive cure.

3. Many MD patients in the Netherlands and Belgium have been using weak asymmetric base-in prisms (WABIPs) as a complementary treatment for over 70 years, with reported positive results.

4. The article aims to provide a possible explanation for the effectiveness of WABIPs based on existing knowledge.

5. The proposed mechanism for WABIPs' effectiveness is related to their ability to address the star-like walking pattern in MD, induced by a drifting after-image similar to the oculogyral illusion.

6. WABIPs may eliminate the conflict between a net vestibular angular velocity bias in the efferent signal controlling the VOR (vestibulo-ocular reflex) and a net re-afferent ocular signal.

7. The article highlights the simplicity, low cost, and social acceptability of WABIP treatment and suggests further exploration of this approach.

8. The article provides background information on MD diagnosis, epidemiology, pathology, and current treatment options.

9. It mentions the placebo effect's role in MD treatment and how some treatments may have a placebo component.

10. The article describes the characteristics of WABIPs, including their prism power, asymmetric distribution, and inward base positioning.

11. The extended Utermöhlen test (EUT) is discussed as a method for determining the appropriate prescription of WABIPs.

12. The EUT involves walking with eyes open toward a luminous line, creating a retinal after-image, and then walking back and forth with closed eyes.

13. The article includes diagrams illustrating the walking patterns of MD patients in the EUT and the potential effect of WABIPs on these patterns.

14. It suggests that WABIPs may help straighten the walking pattern of MD patients and prevent the drift of the after-image.

A 1-Diopter Vertical Prism Induces a Decrease of Head Rotation: A Pilot Investigation

vertical heterophoria

- The study explores the link between vertical heterophoria (VH) and head rotation in healthy individuals.
- VH is the misalignment of the eyes when binocular vision is interrupted briefly, and it can exist in healthy subjects in a physiological range.
- Clinical studies suggest an association between VH and non-specific chronic pain in the neck and back, as well as qualitative balance control and mobility of peripheral joints and the spine.
- The experiment induced VH in healthy subjects using a 1-diopter vertical prism base down on either the dominant or non-dominant eye.
- Subjects were asked to rotate their head three times to the right, then back to the center, and three times to the left while standing upright.
- Results show that the experimental VH induced a significant decrease in the mean angle of head rotation compared to normal viewing conditions.
- The decrease in head rotation was particularly significant for rotations to the left.
- The study suggests that the prism-induced VH may modify the reference posture and, thereby, affect head rotation.
- Further studies are needed to confirm these effects and extend the findings to other types of dynamic activities.

Treatment of vertical heterophoria ameliorates persistent post-concussive symptoms: A retrospective analysis utilizing a multi-faceted assessment battery

vertical heterophoria

- The article examines the effectiveness of neutralizing prismatic lenses in reducing headache, dizziness, and anxiety in patients with persistent post-concussive symptoms and vertical heterophoria (VH).
- Approximately 5-10% of traumatic brain injury (TBI) patients experience persistent post-concussive symptoms, and current treatments are largely unsuccessful.
- The study included 38 patients diagnosed with VH by an optometric binocular vision sub-specialist.
- Data was collected before and after prism application using validated survey instruments for headache, dizziness, anxiety, and BVD symptom burden, as well as subjective ratings.
- The results showed significant reductions (19.1-60.8%) in headache, dizziness, and anxiety measures and an overall subjective improvement of 80.2% in VH symptoms.
- The conclusion is that neutralizing prismatic lenses are an effective treatment for these symptoms in patients with persistent post-concussive symptoms and VH.

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