Volume 14 | Issue 2 | June 2026 An Interview with OEPF Board Chair, Dr. Pamela Schnell Assessment of Fixation Objectively Measuring Acquired Ocular Torsion Secondary to Trochlear Nerve Palsy with Zeiss Cirrus Optical Coherence Tomography Case Series: Optometric Approach to Vision-Related Concussion Symptoms, Diagnosis, and Management Investigating the Factors that Hinder School-Based Vision Screening Programs at Egor Local Government Area, Benin City, Nigeria Effect of Optometric Multisensory Training (OMST) on a Patient with Post-Concussive Visual Snow Syndrome Digital Therapies for Amblyopia Clinical Guide to Einsteinian Low Vision Rehabilitation: Part 2 of 4 The Extensive Relationship Between Eyes and Mind: Understanding the Psychology Behind Your Vision A Comparative Cross-Sectional Study on Amblyopia and its Relationship with Retinal Nerve Fiber Layer Thickness An Approach to Understanding Amblyopia Etiology and Diagnosis
Optometry & Visual Performance 110 Volume 14 | Issue 2 | June 2026 OVP EDITORIAL STAFF For Editorial Staff biographies, please go to http://bit.ly/OVPedit Editor-in-Chief Marc B. Taub, OD, MS, EdD . . . . . ...... mtaub@sco.edu Memphis, Tennessee Managing Editor Pamela H. Schnell, OD . . . . . . ....... pschnell@sco.edu Memphis, Tennessee Associate Editor Steven J. Gallop, OD . .. gallopintovision@comcast.net Broomall, Pennsylvania Associate Editor James Kundart, OD, MEd . . . . .... kundart@pacific.edu Forest Grove, Oregon Associate Editor Rebecca Marinoff, OD . . . . ..... rmarinoff@sunyoptedu New York, New York Advisor Leslie Holland, MLIS . . . . . . . . ........ lholland@sco.edu Memphis, Tennessee SUBMISSION OF MANUSCRIPTS All manuscripts should be submitted via the submission portal at http://bit.ly/OVPed. For more information see the Guidelines for Authors at http://bit.ly/OVPguidelines. Optometry & Visual Performance (OVP) (ISSN #2325-3487) is published quarterly. Copyright 2026 by the Optometric Extension Program Foundation. The entire contents, both text and illustrations of OVP, are copyrighted, and no part may be printed without written permission from the managing editor. All manuscripts and correspondence, including letters, reports, subscriptions, and address changes, should be addressed to the Managing Editor, Pamela Schnell, OD (pschnell@sco.edu). All editorial contributions should be addressed to Marc Taub, OD, MS, EdD (mtaub@sco.edu). All requests for information about advertising should be addressed to Marc Taub, OD, MS, EdD (mtaub@sco.edu). All expressions of opinions and statements of supposed fact published in signed articles do not necessarily reflect the views or policies of the sponsoring organization, OEPF. This organization does not endorse any specific educational program or products advertised in OVP. Acceptance of advertising or optical industry news for publication in OVP does not imply approval or endorsement of any product or service by either OVP or the sponsoring organization, OEPF. MISSION STATEMENT Optometry & Visual Performance (OVP) is an international, peer-reviewed journal dedicated to the advancement of the role of optometry in enhancing and rehabilitating visual performance. The mission of OVP is to increase the awareness and availability of clinically relevant information in functional, developmental, behavioral, and vision therapy aspects of optometry through an internet-based, open-access format. OVP is an effort of the Optometric Extension Program Foundation (OEPF). ISSN 2325-3487 Volume 14 | Issue 2
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Optometry & Visual Performance 113 Volume 14 | Issue 2 | June 2026 Marc Argiles Sans, MSc, PhD Catalonia, Spain Emily Aslakson, OD Big Rapids, Michigan Patti Andrich, MA, OTR/L North Royalton, Ohio Surbhi Bansal, OD Palo Alto, California Marsha D. Benshir, OD Olney, Maryland Rebecca Charlop OD Brooklyn, New York Eric Chow OD Miami, Florida Kenneth Ciuffreda, OD, PhD New York, New York Mark Dean, OD Myrtle Beach, California Jennifer Fisher, OD Berkeley, California Christian French, PhD MOptom (Hons) MCOptom Leicester, United Kingdom Nick Fogt, OD, MS, PhD Columbus, Ohio Robert Fox, OD Latham, New York Ronald A. Gall, OD Ontario, Canada Liat Gantz, BOptom, BSc, PhD Jerusalem, Israel Katherine Green, OD Boston, Massachusetts Tom Headline, BS San Carlos and Aptos, California Charlie Ho, OD, ME, JD Quezon City, Philippines Jamie Ho, OD Nashville, Tennessee Rizwana Hussaindeen, OD, PhD Ajman, United Arab Emirates Alison Jenerou, OD Big Rapids, Michigan Gregory Johnson, OD Manassas, Virginia Kenneth Koslowe, OD, MS Petach Tikva, Israel Jeffrey J. Lant, OD O’Fallon, Missouri Ira Krumholtz, OD Franklin Park/Edison, New Jersey Don Lyon, OD, MS Bloomington, Indiana Stacy Lyons, OD Boston, Massachusetts Revathy Mani, PhD Sydney, NSW, Australia David Maze, OD Memphis, Tennessee Thokozile Ingrid Metsing, D.Phil Doornfontein, South Africa Jason Ng, OD, PhD Fullerton, California Morgan Ollinger, OD, MS Memphis, Tennessee Tamara Petrosyan, OD New York, New York Tuwani Rasengane Bloemfonteine, South Africa Matthew Roe, OD Glendale, Arizona Haya Glick Shames, Optometrist, MS, PhD Jerusalem, Israel Barry Tannen, OD Hamilton Square, New Jersey Emelio Teran, MsC, PhD Sinola, Mexico Andrea Thau, OD New York, New York Jaci Theis, OD Richmond, Virginia Eric Weigel, OD Greensburg, Indiana Melanie Woddhouse, B. Optom Manly, Sydney, Australia Naveen Yadav, MS, PhD Pomona, California OVP JOURNAL REVIEW BOARD ISSN 2325-3487 Volume 14 | Issue 2 For OVP Journal Review Board Members’ biographies, please go to https://bit.ly/OVP_review
Optometry & Visual Performance 114 Volume 14 | Issue 2 | June 2026 Editorial: An Interview with OEPF Board Chair, Dr. Pamela Schnell . . . . . . . . . . . ............. 117 Viewpoint: Assessment of Fixation . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................ 121 Kenneth J. Ciuffreda, OD, PhD • SUNY College of Optometry • New York, New York Daniella Rutner, OD, MS, MBA • SUNY College of Optometry • New York, New York Article: Objectively Measuring Acquired Ocular Torsion Secondary to Trochlear Nerve Palsy with Zeiss Cirrus Optical Coherence Tomography . . . . . . . . . . . . . . . . ................. 125 Christopher J. Borgman, OD • Southern College of Optometry • Memphis, Tennessee Article: Case Series: Optometric Approach to Vision-Related Concussion Symptoms, Diagnosis, and Management . . . . . . . . . . . . . . . . . . . . . . . . . ........................... 130 Zuzana Rutenberg, M. Optom • Jerusalem Multidisciplinary College • Jerusalem, Israel Rachel Eichler, OD • Jerusalem Multidisciplinary College • Jerusalem, Israel Liat Gantz, PhD • Jerusalem Multidisciplinary College • Jerusalem, Israel Article: Investigating the Factors that Hinder School-Based Vision Screening Programs at Egor Local Government Area, Benin City, Nigeria . . . . . . . . . . . . . . . ................ 139 Daniel Ayodele Femi, OD • University of Benin • Edo, Nigeria Okechukwu Clinton Ifeanyi, OD • University of Benin • Edo, Nigeria TABLE OF CONTENTS ISSN 2325-3487 Volume 14 | Issue 2
Optometry & Visual Performance 115 Volume 14 | Issue 2 | June 2026 Article: Effect of Optometric Multisensory Training (OMST) on a Patient with PostConcussive Visual Snow Syndrome . . . . . . . . . . . . . . . . . . . . . . ........................ 146 Bradley E. Habermehl, OD • Western University of Health Sciences, College of Optometry . . ... Pomona, California Naveen K. Yadav, MS, PhD • Western University of Health Sciences, College of Optometry Pomona, California Article: Digital Therapies for Amblyopia . . . . . . . . . . . . . . . . . . . . . . . . ......................... 154 Man Kin (Eric) Chow, OD • Miami, Florida Article: Clinical Guide to Einsteinian Low Vision Rehabilitation: Part 2 of 4 . . . . . . . ......... 159 Bennett McAllister, OD • Western University of Health Sciences • Pomona, California Article: The Extensive Relationship Between Eyes and Mind: Understanding the Psychology Behind Your Vision . . . . . . . . . . . . . . . . . . . . . . . . ......................... 170 Pratyush Dhakal, MPH, Optometrist • Nepal Eye Hospital • Kathmandu, Nepal Amrita Samanta Dhakal • National Academy of Medical Sciences (NAMS) • Kathmandu, Nepal Article: A Comparative Cross-Sectional Study on Amblyopia and its Relationship with Retinal Nerve Fiber Layer Thickness . . . . . . . . . . . . . . . . . . . . . ....................... 174 Muhammad Asad Saeed, BS Optom Azka Sadat, MS HCM, BS Optom Fareeha Ayyub, M Phil Optom Amtul Aziz, DOMS, MBBS Rida Fatima, BS Optom Qurat ul Ain, BS Optom Pakistan Institute of Ophthalmology, Al-Shifa Trust Eye Hospital • Rawalpindi, Pakistan Student Corner: An Approach to Understanding Amblyopia Etiology and Diagnosis . . .... 181 Tamara Petrosyan, OD • SUNY College of Optometry • New York, New York TABLE OF CONTENTS ISSN 2325-3487 Volume 14 | Issue 2
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Optometry & Visual Performance 117 Volume 14 | Issue 2 | June 2026 G!) as my supervisor was a privilege; I learned a tremendous amount from him about infant care. I am honored to say that he quickly became a close friend and mentor. During the year, I also had the opportunity to learn from a number of other notable optometrists in the areas of pediatrics and vision therapy, including. Harold Solan, Dr. Israel Greenwald, Dr. Ira Krumholtz, Dr. Sid Groffman, Dr. Neera Kapoor, Dr. Ida Chung, and Dr. Marilyn Vricella. All of these (and many more) showed me the wide variety of philosophies and treatment protocols available to us in pediatric care. Fitz (he goes by no other name) also inspired in me a love of teaching that provided me with a completely new direction for my future, and I’m so grateful! What was your path to becoming an educator? See above What led you to come back to SCO as an educator? Throughout my years at SUNY (I stayed on faculty there for a total of ten years to the day from the start of my residency) I always imagined one day being able to have a lifestyle more similar to what I had grown up with: a house outside the city and (finally!) a dog! I loved the people I worked with at SUNY, and I enjoyed life in NYC, but living in the Big Apple carries a level of background energy that can get to be a bit much as one gets older! I had stayed in touch with several friends back at SCO, and when one mentioned at an alumni event that they were looking for peds people— and my husband and I realized that the timing was right—we were off to Tennessee. When did you join OEPF and why? I joined OEPF in 2018 when I became a Director/ Trustee for the organization. I had been introduced to the behavioral philosophy when I returned to SCO, and I quickly fell in love with the holistic nature of the diagnostic and treatment ideas contained in it. To have an opportunity to serve the organization as a Board member seemed like something that I might do at some point, but the need arose to fill a position, and I was thrilled to accept! What are your responsibilities are Board Chairperson? As Board Chair for OEPF, my responsibilities largely involve working closely with our President What is your educational background? UNC Chapel Hill, BS Biol, 1996 SCO, OD, 2001 SUNY, Pediatric Optometry Residency, 2001 What was your motivation to become an optometrist? Lifelong interest & glasses as a young kid Tell us about your optometry school experience and how it shaped your desire to do a residency. Prior to optometry school, I enjoyed several opportunities to work with children, including working as an Assistant Leader for a local Girl Scout troop and teaching young children at church. I became interested in pediatric care during my 3rd year of optometry school, when we began seeing older kids come through our primary care clinics. I had enjoyed participating in school vision screenings during our 2nd year as well, and early clinical experience solidified that interest. Tell us about the residency program. I spent a fantastic year in pediatric optometry at the State University of New York College of Optometry. Working with Dr. David FitzGerald (always a capital Editorial • An Interview with OEPF Board Chair, Dr. Pamela Schnell
and CEO, Line Vreven, to ensure that the Foundation continues to run smoothly day-to-day. Through the internationally known Clinical Curriculum, our newly established Wednesday night lecture series, several chat groups for both students and practitioners, and a wide variety of publications, our mission of providing up-to-date, inspiring education in behavioral vision is well supported. We also sponsor the International Congress of Behavioral Vision (ICBO) once every four years, which brings together vision therapy organizations from all over the world in one location to learn from, collaborate with, and enjoy growing friendship with doctors and therapists who all love VT! Our next ICBO will be March 1-4, 2028, in Las Vegas, Nevada. We will also celebrate OEPF’s Centennial, so it’s going to be a fantastic celebration—we’d LOVE to see you there! You also serve as the Managing Editor for OVP, how did that happen and what does that entail? I began working with OVP’s forerunner, the Journal of Behavioral Optometry, in 2011, serving as their Associate Editor. When that journal’s run came to an end and we founded OVP, it was natural for me to move into the same role at the new publication. After a year or so, I was promoted to Managing Editor and have thoroughly enjoyed working with Dr Marc Taub and the Associate Editors to bring you this amazing international collaboration! How do you think OEPF can serve the next generation of optometrists? As we learn more and more about the links between neuroscience and vision rehabilitation, it has become more and more obvious to me that the behavioral philosophy—a holistic approach to vision therapy that pays close attention to the patient’s underlying reasons for the visual adaptations that they have made—is the best way to help guide patients to their best visual potential. Moving into the future, OEPF can not only help established providers become more experienced with their VT, but it can also inspire whole new groups of ODs who want to expand their practices into new and exciting areas of patient care. We’re here for you, come check us out! What are your hobbies and how do you relax in your non-optometry time? I’m a bit of a homebody, so I enjoy spending time there with my husband and our dogs! I love to read and crochet and be able to relax doing “nothing” on occasion, but I also love seeing new places and being able to travel when the opportunity comes along. I have had several opportunities to lecture in locations across the world, including Israel, South Africa, Mexico, Canada, and most recently Poland. A bit more than a hobby now, I am also a semiprofessional musician. I have played a number of instruments since childhood and still perform on flute fairly regularly. I started singing as a young child in church choirs and picked up that again when I moved to New York; I met my husband David in the Marble Collegiate Church choir in the city, a classical tenor who inspired me to keep learning. We’ve been singing together in various choirs and organizations ever since! I am currently a member of the choir at First Baptist Church in Memphis (my home congregation), and I do gig work for a number of others, most notably St. John’s Episcopal Church, with whom I have had the honor of traveling to both Ireland and the UK to participate in choral residencies at St Patrick’s Cathedral in Dublin and Liverpool Cathedral in England. I am also a member of the Memphis Symphony Chorus and the Memphis Symphony Chamber Choir, so my weeks are kept busy! I honestly wouldn’t know how to live a life without music and am so grateful for the opportunities I’ve had. Optometry & Visual Performance 118 Volume 14 | Issue 2 | June 2026 Check out this new book from OEPF!
Optometry & Visual Performance 121 Volume 14 | Issue 2 | June 2026 Viewpoint • Assessment of Fixation Kenneth J. Ciuffreda, OD, PhD • SUNY College of Optometry • New York, New York Daniella Rutner, OD, MS, MBA • SUNY College of Optometry • New York, New York The ability to fixate accurately and stably is critical for optimal viewing of the world. However, many of our patients do not fixate well.1 This would include those with nystagmus, macular degeneration, optic atrophy, albinism, stroke, traumatic brain injury, and more.1-3 Thus, it is incumbent upon the optometrist and others (e.g., a vision therapist or neurologist) to assess a patient’s fixational ability appropriately. In this paper, various methods for assessing fixation, both traditional clinical and objective approaches, will be considered. Table 1 presents a wide array of the more traditional clinical approaches to assess fixation.1,4,5 Gross visual observation is perhaps the most common and simplest approach, although it requires excellent observational skills and knowledge of potential abnormalities on the part of the clinician (Figure 1). The doctor has the patient fixate upon a small target, such as a pen tip or Wolff wand, for 10 seconds (or more), monocularly and binocularly, and integrates by visual memory what is observed, such as the number of fixational losses and their estimated magnitudes, differences noted between each eye and binocularly, the presence of large saccadic intrusions or drift, subtle nystagmus, and more.1 Then it is repeated across different diagnostic gaze positions (e.g., downgaze in reading). This is an adequate screening tool for detecting gross abnormalities. It can also be performed using the slit-lamp for higher Kenneth J. Ciuffreda, OD, PhD New York, New York SUNY College of Optometry, Distinguished Teaching Professor Emeritus PhD, UC-Berkeley/Optometry, 1977 OD, Massachusetts College of Optometry, 1973 BA, Seton Hall University, 1969 Fellow Dipl-AAO, ARVO, COVD, & NAP magnification and hence better detectional ability, especially for abnormalities such as subtle, small, intermittent nystagmus.1 The next four approaches listed in Table 1 mainly apply to the assessment of eccentric fixation (EF) in amblyopic eyes. The Haidinger brush technique is very useful, as it is easy for the patient to visualize, readily provides both direction and magnitude, and can be performed in a young child. The others listed are rarely used in the clinic. The last approach, however, namely 30-second, lowlight visuoscopy developed by Selenow and Ciuffreda,4 is extremely useful and very informative. It not only provides the EF location but also allows the clinician to observe directly on the retina the actual fixational pattern and the underlying types of eye movements (e.g., increased amblyopic drift). It was based in part on an earlier experiment by Lawwill in 1966,4 in which he observed that excessive light intensity exacerbated, or even“created”(i.e., iatrogenically induced), any fixational abnormalities. Hence, what Selenow and Ciuffreda developed and tested was a low-light technique. Thus, the light intensity of the visuoscope is reduced until the doctor can “just” detect the projected calibrated grid and central target on the patient’s fundus. Of course, the patient readily perceives it. The patient is then instructed to fixate carefully on the central target. Since EF is a time-average, perceptual-motor phenomenon,4 the foveal/macular region is assessed for 30 seconds (or more) to build up a sufficient mental image of the EF’s direction, magnitude, variability, and overall pattern. The observed details are then fully described and recorded. The fellow eye is likewise tested for comparative purposes. It is repeated during the course of therapy to assess for likely reduction and hopefully Gross visual observation Angle kappa determination Blind spot comparison Maxwell's spot Haidinger's brush Visuoscopy Table 1. Traditional Clinical Approaches to Assess Fixation Figure 1. Test of fixation by visual observation
Optometry & Visual Performance 122 Volume 14 | Issue 2 | June 2026 the attainment of consistent and accurate foveation. Table 2 presents some of the objective approaches to assess fixation. This allows for a more detailed, quantitative, and unbiased appraisal of fixational ability, including the overall pattern and types of abnormal eye movements (e.g., increased amblyopic drift, large saccadic intrusions). An early approach was the infrared, horizontal, limbal technique (Figure 2).1 Basically, the eyes are bathed with safe levels of infrared light, and the two detectors for each eye are aimed at the horizontal nasal and temporal regions to assess the differential light reflection on the sensors: the white sclera reflects more light than the darker iris. This type of system has been used in many laboratories over the past 75 years, as well as in the clinical domain (e.g., ReadAlyzer; https://www. compevousa.com/). Again, the patient is instructed to fixate carefully on a small target on a screen, usually 4057 cm away along the midline in the primary position, for several seconds. The resultant horizontal fixational pattern can be viewed as a function of time, printed out for the record, and even quantified if a prior calibration was performed. Newer technology uses a video-based approach (Figure 3).1 Here, small video cameras are aimed at each eye, and both the horizontal and vertical eye movements are recorded during fixation. Thus, this provides a more complete picture of fixation. These systems are easy for the clinician to use and provide a wide linear range of movement for accurate assessment. This includes various laboratory devices (e.g., Tobii; https://gaming.tobii.com/) as well as clinical devices (e.g., RightEye; https://righteye.com/). However, the latter system does not allow for testing of fixation under monocular conditions, which is critical for both EF assessment in amblyopic eyes, as well as eccentric viewing (EV) assessment in ocular disease/visual field loss situations; furthermore, it does not present the eye movements as a function of time like most instruments do. Rather, it presents each fixational sample in x,y Cartesian coordinate space with disregard for time. The third and newest approach has been the use of microperimetry for fixational testing (Figure 4).7-9 This involves direct visualization of the fundus area of interest (similar to visuoscopy), typically the foveal/ macular region of only one eye. The patient is asked to fixate the target carefully, and the calibrated system samples both the horizontal and vertical eye positions at 25 Hz (i.e., 25 samples per second) or higher for 30 seconds. Once the test is completed, an overlay of the area of fixation is presented as a series of calibrated bivariate ellipses, typically enclosing the retinal regions of fixation 25, 50, 75, and 100% of the time:1 the less fixational scatter, the smaller the ellipse, and the better the fixation. From this, one can obtain the retinal point of maximal fixation and its variability, all objectively documented—that is, either the fovea, the EF point, or the EV point. This approach is so important because the Infrared limbal sensing Video recording Microperimetry Table 2. Objective Approaches to Assess Fixation Figure 2. Infrared limbal eye movement system Figure 3. Tobii eye tracking video system assessing reading eye movements Figure 4. Microperimetry showing eccentric and unsteady fixation in an amblyope
clinician can visualize the oculomotor activity and the visuomotor, spatial centrode directly on the patient’s fundus in real time. In conclusion, the clinical and laboratory assessment of fixation in our patients has expanded greatly over the past 20 years. This is mainly the result of improved technology and rapid automated analyses, with excellent graphical display for the clinical record. Such objective documentation is helpful for the parent to understand how the abnormal eye movements negatively impact their child (e.g., slowed reading), as well as for presentation as an expert witness in the courtroom.10 Future technological advances are likely to include expanded use of virtual/augmented reality to create more naturalistic viewing/testing scenarios. Acknowledgements: We thank Dr. Putnam for her discussions regarding microperimetry and Dr. Wang and Bhavatharini Ramakrishnan for providing the microperimeter fundus image. References 1. Ciuffreda KJ, Tannen B. Eye Movement Basics for the Clinician. St. Louis: Mosby, 1995. 2. Han Y, Ciuffreda KJ, Kapoor N. Reading-related oculomotor training protocols for acquired brain injury in humans. Brain Res Brain Res Protocols 2004;14:1-12. 3. Ciuffreda KJ. Eye Movements in Patients with Oculomotor Disturbances. In: Ygge J, Lennerstrand G. (eds.). Eye Movements in Reading. New York: Pergamon; 1994: 168-88. 4. Ciuffreda KJ, Levi D, Selenow A. Amblyopia: Basic and Clinical Aspects. Boston: Butterworth-Heinemann, 1991. 5. Schapero M. Amblyopia. New York: Chilton Book Co., 1971. 6. Lawwill T. The fixation pattern in the light-adapted and darkadapted amblyopic eye. Am J Ophthalmol 1966;61:1416-9. 7. De Guimaraes TAG, Kalitzeos A, Bainbridge J, Michaelides M. Distance from the foveal center: A method for the calculation of eccentric fixation. Transl Vis Sci Technol 2025;14(5):9. 8. Molina-Martin A, Perez-Cambrodi RJ, Pinero DP. Current clinical application of microperimetry: A review. Sem Ophthalmol 2018; 33:620-8. 9. Seiple W, Rosen RB, Castro-Lima V, Garcia PMT. The physics and psychophysics of microperimetry. Optom Vis Sci 2012;89:118291. 10. Ciuffreda KJ, Tannen B, Rutner D, Yadav NK, Suter PS. Objective vision-based testing in mild traumatic brain injury. Vis Dev Rehabil 2023:9:127-32. Correspondence regarding this article should be emailed to Kenneth J. Ciuffreda, OD, PhD at kciuffreda@sunyopt.edu. All statements are the authors’ personal opinions and may not reflect the opinion OEPF, OVP, or any institution with which the authors may be affiliated. Permission to use reprints of this article must be obtained from the editor. Copyright 2025 OEPF. Ciuffreda KJ, Rutner D. Assessment of fixation Optom Vis Perf 2025;14(2):121-3. Optometry & Visual Performance 123 Volume 14 | Issue 2 | June 2026 Hard Copy E-book
A Vital Cornerstone of Vision Science: The Rediscovered Works of Dr. Frederick W. Brock Unearth the Foundational Principles That Shaped Modern Practice. For medical professionals, researchers, and students committed to the deep understanding of vision and its mechanisms, the Optometric Extension Program Foundation (OEPF) is proud to present a meticulously restored volume of the essential works of Dr. Frederick W. Brock, D.O.S. Originally published as a landmark serialization in Optometric Weekly from 1947 to 1957, Dr. Brock’s writings offer profound insight into the clinical and theoretical concepts that underpin contemporary vision care. These texts represent a crucial link to the historical development of our field yet have been largely inaccessible for over seventy years. Visual Training (2-Part Set): Visual Training Preliminary Considerations Part 1 The Problem of Subnormal Vision and Amblyopia Part 2 What This Volume Offers You: This book includes the first and second parts in a planned threepart sequence, bringing Dr. Brock’s complete decade-spanning contribution back into circulation. It is an indispensable addition to any clinical or academic library, offering: Historical Context: A direct look at the evolution of key diagnostic and therapeutic vision concepts. Primary Source Material: The opportunity to study the original ideas of a foundational figure. Enhanced Clarity: A cleaned and verified text, making complex historical concepts accessible for modern study.
Optometry & Visual Performance 125 Volume 14 | Issue 2 | June 2026 Article • Objectively Measuring Acquired Ocular Torsion Secondary to Trochlear Nerve Palsy with Zeiss Cirrus Optical Coherence Tomography Christopher J. Borgman, OD • Southern College of Optometry • Memphis, Tennessee Introduction Abnormal cyclotorsion has been known to occur with acquired ocular torsion disorders such as trochlear nerve palsies and skew deviations.1-5 Historically, the most common way to measure ocular torsion objectively has been with fundus photography.2-5 Newer reports document OCT as another tool to measure objective ocular torsion in acquired cases.1,6-8 This case expands on previous OCT ocular torsion reports using Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany)1,6,8 to include Cirrus OCT (Carl Zeiss Meditec, Dublin, California, USA) as a potential way to assess acquired ocular torsion disorders. Case Report A 68-year-old female presented for routine eye examination, with a chronic vertical diplopia complaint for five years since she suffered a brainstem stroke secondary to her history of hypertension and diabetes mellitus. Her diplopia disappeared when covering either eye, suggesting binocular vision dysfunction. She was able to alleviate her diplopia fully in primary gaze with a small left head tilt. Her medical history included hypertension and osteoporosis. Visual acuity was 20/20 OD and 20/25 OS. Pupils, extraocular motilities, and confrontation visual fields were normal OU. Cover test revealed a 2Δ hyper deviation OD. With the Parks-Bielschowsky three-step test, the hyper deviation worsened with right head tilt and in left gaze, suggesting right superior oblique weakness.1,2,4 External examination was unremarkable OU. Retinal examination was unremarkable except for mild macular drusen OU. Increased excyclotorsion (-11°) of the right eye and normal torsion (-4°) of the left eye were noted objectively with fundus photography, consistent with a mild trochlear nerve palsy OD (Figure 1). Cirrus OCT macular thickness scans were also performed on the patient OU. Using the linear measuring tool embedded within the Cirrus OCT software, two linear micron measurements were drawn: one from the center of the optic nerve to the fovea, and the second to estimate the horizontal meridian. Using these linear OCT measurements, the disc-to-fovea angle was calculated to estimate the amount of ocular torsion present in each eye (-11.4° OD, -6.6° OS; Figure 2). This shows a Christopher J. Borgman, OD Memphis, Tennessee Associate Professor, SCO BA, 2006, Central College, Pella, Iowa OD, 2010, Illinois College of Optometry, Chicago, Illinois Residency, 2011, Primary Care and Ocular Disease, Illinois College of Optometry Fellow of the American Academy of Optometry ABSTRACT Background: Optical coherence tomography (OCT) allows the identification of key fundus landmarks (fovea and center of optic disc) to help calculate estimated ocular torsion amounts in acquired ocular torsion disorders. A case of chronic trochlear nerve (CN IV) palsy secondary to stroke, in which objective ocular torsion was measured with OCT software and basic trigonometric calculations, follows in this report. Case Report: A 68-year-old female patient with a history of brainstem stroke from five years earlier showed a right-eye hyper deviation of 2Δ. Resultant Parks-Bielschowsky three-step testing, as well as ocular torsion testing with OCT software measurements, helped determine that the patient’s hyper deviation was secondary to a right CN IV palsy. Her objective ocular torsion was calculated using measurement tools and trigonometric functions derived from her OCT scans. Conclusions: OCT technology can provide objective methods for measuring ocular torsion in acquired ocular torsion disorders. Potential OCT software development and future study regarding the use of OCT in these ocular torsion disorders is needed. Keywords: ocular torsion, optical coherence tomography, trochlear nerve palsy
Optometry & Visual Performance 126 Volume 14 | Issue 2 | June 2026 Figure 1. Standard fundus photography of the right eye (OD) and left eye (OS). Note the increased excyclotorsion OD (-11.0°) compared to the normal ocular torsion OS (-4.0°). This is consistent with a right trochlear nerve palsy. Figure 2. Optical coherence tomography (OCT) of the patient in this case using Cirrus OCT (Cirrus 5000, Carl Zeiss Meditec, Dublin, California, USA) macular thickness scans of the right eye (OD) and left eye (OS). The standard measuring tool on the Cirrus OCT was used to measure the linear distance (microns) from the center of the optic nerves to the fovea (red line with red arrow) and the horizontal meridian (red line with black arrow). These two distances were used to estimate the disc-to-fovea angle with the cosine trigonometric calculations below each respective photo (-11.4° OD, -6.6° OS). The excessive excyclotorsion of the OD is consistent with a right trochlear nerve palsy.
nice correlation between the objective measures of ocular torsion in this case, as obtained from fundus photography and OCT. Discussion The ability of OCT to measure ocular torsion is based upon its ability to estimate the angle between a line drawn from the optic nerve center to the fovea and the true horizontal plane, called the “disc-fovea angle.”5,9 Previously documented mean normal ranges of cyclotorsion with Spectralis OCT have been reported to be -6.6° ± 2.8°.5 A recent study compared cyclotorsion with Spectralis OCT in normal versus trochlear nerve palsy patients.9 This study reported average cyclotorsion in trochlear nerve palsies of -11.3° (range: -7.7° to 14.9°).9 However, to the author’s knowledge, studies of other OCT platforms to measure cyclotorsion specifically, such as the Cirrus OCT used in this case, do not exist. The Cirrus OCT has a measuring tool within its standard software capable of measuring linear distances (microns). Using this tool to measure the distance from the fovea to the center of the optic nerve, and then measuring a second distance from the fovea along the horizontal meridian to form a right triangle, a clinician could perform a simple trigonometric cosine calculation to estimate the disc-fovea angle. This would then allow the clinician to document the degree of ocular torsion, as in this case (Figure 2). Additionally, the true foveal center can be easily identified on standard OCT macular thickness scans, allowing more accurate ocular torsion measurements. Since the patient was able to alleviate her vertical diplopia with a small head tilt, she declined further treatment beyond monitoring in this case. The patient is being followed on a yearly basis due to the chronicity and stability of her vertical deviation. The patient’s systemic risk factors (i.e., hypertension and diabetes mellitus) account for her stroke history and subsequent trochlear nerve palsy in this case. Given the known anatomy of the trochlear nerves, the likely lesion location in this case is either the inferior dorsal midbrain (at the level of the inferior colliculus) or further along the trochlear nerve’s course towards the superior oblique muscle, involving the nerve’s vasa-nervorum blood supply.10 Conclusion Cirrus OCT platforms, along with some basic trigonometric calculations, can provide an objective Optometry & Visual Performance 127 Volume 14 | Issue 2 | June 2026 means to estimate degrees of cyclotorsion in acquired ocular torsion disorders, such as this case of trochlear nerve (CN IV) palsy. This is important since some patients are subjectively poor responders to classic tests that measure ocular torsion, such as the double Maddox rod. OCT has the potential to provide objective measures of ocular torsion that do not depend on patients’ subjective responses. Potential OCT software development and future study regarding the use of OCT in these ocular torsion disorders is needed and should be encouraged. References 1. Borgman CJ, Haynes JA. Measuring acquired ocular torsion with optical coherence tomography. Clin Exp Optom 2021;104:132-4. 2. Roh YR, Hwang JM. Comparison of subjective and objective torsion in patients with acquired unilateral superior oblique muscle palsy. Br J Ophthalmol 2011;95:1583-7. 3. Sharpe JA, Kumar S, Sundaram AN. Ocular torsion and vertical misalignment. Curr Opinion Neurol 2011;24:18-24. 4. Lee JJ, Chun KI, Baek SH, Kim US. Relationship of hypertropia and excyclotorsion in superior oblique palsy. Korean J Ophthalmol 2013;27:39-43. 5. Lengwiler F, Rappoport D, Jaggi GP, Landau JK, et al. Reliability of cyclotorsion measurements using scanning laser ophthalmoscopy imaging in healthy subjects: The CySLO study. Br J Ophthalmol 2018;102:535-8. 6. Borgman CJ, Follansbee CJ. Degree of excyclotorsion in an acquired trochlear nerve palsy. Clin Exp Optom 2020;103:550-1. 7. Sophocleous S. Use of optical coherence topography for objective assessment of fundus torsion. BMJ Case Rep 2017:bcr2016216867. 8. Kanku MS, Sele S, Held U, et al. Cyclotorsion measurement on scanning laser ophthalmoscopy imaging compared with fundus photography in patient with fourth nerve palsy and healthy controls: CySLO-IV study. J Neuroophthalmol 2021;41(4):e612-e618. 9. Amini N, Nowroozizadeh S, Cirineo N, Henry S, et al. Influence of the disc-fovea angle on limits of RNFL variability and glaucoma discrimination. Invest Ophthalmol Vis Sci 2014;55:7332-42. 10. Morillon P, Bremner F. Trochlear nerve palsy. Br J Hosp Med 2017;78:C38-C-40. Correspondence regarding this article should be emailed to Christopher J. Borgman, OD, at cborgman@sco.edu. All statements are the author’s personal opinions and may not reflect the opinions of the representative organization, OEPF, Optometry & Visual Performance, or any institution or organization with which the author may be affiliated. Permission to use reprints of this article must be obtained from the editor. Copyright 2026 Optometric Extension Program Foundation. Online access is available at www.oepf.org and www.ovpjournal.org. Borgman CJ. Objectively measuring acquired ocular torsion secondary to trochlear nerve palsy with Zeiss cirrus optical coherence tomography. Optom Vis Perf 2026;14(2):125-7.
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Optometry & Visual Performance 130 Volume 14 | Issue 2 | June 2026 Article • Case Series: Optometric Approach to Vision-Related Concussion Symptoms, Diagnosis, and Management Zuzana Rutenberg, M. Optom • Jerusalem Multidisciplinary College • Jerusalem, Israel Rachel Eichler, OD • Jerusalem Multidisciplinary College • Jerusalem, Israel Liat Gantz, PhD • Jerusalem Multidisciplinary College • Jerusalem, Israel ABSTRACT Background: Sport-related concussions frequently result in persistent visual dysfunctions, including accommodative, binocular, oculomotor, and oculo-vestibular impairments. These deficits can significantly impact quality of life and are often overlooked in standard eye examinations. Optometric vision therapy offers targeted rehabilitation to address these dysfunctions. This case series highlights the benefit of vision therapy in three female patients with sport-related concussions referred for visual evaluation and treatment long after the concussion was sustained. Case Reports: Three patients (ages 20, 27, and 34) with persistent visual symptoms years after one or more concussions were previously examined by eye care providers, yet visual complaints remained unresolved. Each underwent a comprehensive binocular vision assessment revealing various combinations of accommodative excess (patients 1, 2, 3) or insufficiency (patient 2), fusional vergence dysfunction (patients 2, 3), oculomotor deficits (patients 1, 2, 3), and vestibulo-ocular dysfunction (patients 1 ,2, 3). Patients completed 11–12 sessions of individualized vision therapy, supplemented by daily home exercises. Following therapy, all patients demonstrated clinically significant improvements in objective findings and selfreported symptoms. Brain Injury Vision Symptom Survey scores improved by 55–59% (34–35 points) Introduction Concussion, often referred to as mild traumatic brain injury (mTBI), is defined by the Centers for Disease Control and Prevention (CDC) as injury to the brain resulting from abrupt acceleration and deceleration of the head during impact, causing the brain to collide or twist with the skull, thereby damaging brain cells and triggering chemical changes.1,2 Diagnosing concussion can be challenging due to rapid fluctuations in signs or symptoms3 and potential delayed inflammatory responses.4–6 A recent Delphibased framework developed diagnostic criteria, which include the mechanism of injury, clinical signs, acute symptoms, clinical examination findings, and neuroimaging.7 Visual symptoms after concussion frequently include blurred vision, photosensitivity, dizziness, headaches, and difficulties with eye coordination or depth perception.8 Convergence insufficiency (CI) and accommodative disorders are common in individuals after mTBI.9,10 These visual disorders can significantly impair everyday tasks11 and impede academic, occupational, and athletic performance. They may also limit attendance at school, work, or sports,2 resulting in both an economic and mental burden. Zuzana Rutenberg, M. Optom Reykjavík, Iceland Augnlæknastofan í Mjódd, Iceland M. Optom, Jerusalem Multidisciplinary College, 2025 B. Optom, Jerusalem Multidisciplinary College, 2005 across the three cases. Notable functional gains included reduced photophobia, improved reading, less fatigue, and return to academic or physical activities. Conclusions: This case series underscores the essential role of optometrists in post-concussion care. Optometric vision therapy is an effective intervention, even when initiated long after the initial injury. Comprehensive visual function assessment and interdisciplinary collaboration are critical to identifying and managing postconcussion visual dysfunction, ultimately improving patient outcomes. Keywords: concussion, optometric vision therapy, traumatic brain injury
Optometry & Visual Performance 131 Volume 14 | Issue 2 | June 2026 Growing evidence demonstrates the efficacy of optometric interventions such as vision therapy in mitigating visual deficits and symptoms and enhancing functional vision and quality of life in individuals following head injury.12 Table 1 summarizes key studies that illustrate the range of positive outcomes associated with these interventions, including oculomotor control, convergence ability, and patient-reported quality of life. The publications encompass single-case reports, small case series, and one large retrospective study, demonstrating clinical benefits across diverse age groups and injuries. This case series presents the long-term follow-up of three patients recovering from one or two sportrelated concussions with concurrent vision disorders (1, 2, and 5 years since the last injury), demonstrating how optometric evaluation and intervention can effectively manage post-concussion syndrome and support sustained improvements in visual function. Case Reports Three female patients were seen by an optometrist (ZR) in Reykjavík, Iceland in 2023. All patients sustained one or more sport-related concussions and were referred by their physiotherapist or cognitive therapist for a binocular visual evaluation due to their visual symptoms, despite having previously been seen by an eye care practitioner. Case Report 1 A 27-year-old female sustained a concussion without loss of consciousness in December 2021 after falling backward while ice-skating. She immediately developed headaches and was advised to rest. During a seven-day follow-up phone consultation, she was prescribed citalopram, esomeprazole, Selexid, Norgesic, melatonin, Atarax, and Botox. In June 2022, she began physiotherapy, receiving acupuncture and cognitive therapy for persistent headaches, fatigue, reading difficulties, and photophobia, which worsened with computer use. She was referred to the optometry clinic by her cognitive therapist and was evaluated in September 2023. The patient was a compound myope who reported wearing spectacles for the past seven years. Her most recent eye examination was in 2022, with a prescription of -1.00-0.50x170 OD and -1.00 -0.25x010 OS. Examination findings are presented in Table 2. Unaided visual acuity was 0.52 logMAR OD and 0.40 logMAR OS, improving to 0.00 logMAR in both eyes with subjective refraction of -1.00 OD and -0.25-0.25x030 OS. Cycloplegic refraction with 1% cyclopentolate yielded plano-0.75x175 OD and -0.25 -0.50x030 OS, both achieving 0.00- logMAR acuity. At follow-up six days later, non-cycloplegic refraction was -0.50-0.25x165 OD and -0.25-0.50x010 OS, with 0.00- logMAR acuity in both eyes. This prescription was dispensed. As described in Table 2, cover testing revealed distance orthophoria and 2Δ esophoria at near. She was able to converge to the nose without reporting double vision but was unable to clear the +2.00 D lens during monocular and binocular accommodative facility (MAF/BAF). Her dynamic monocular estimation method (MEM) retinoscopy was plano. Her negative relative accommodation (NRA) was +1.00, often indicating accommodative excess. Due to the reported reading difficulties, the King Devick test was administered, and her score was equivalent to 10 years old. During the vestibuloocular motor screening (VOMS) test, she reported an increase in headaches. Her brain injury symptom survey (BIVSS) score was 75 (predictive score is > 31).13 The Maples oculomotor test findings included head movements, undershooting on saccades, and Author(s) Study Design Participant(s) Age (years) Key Findings / Takeaways Ciuffreda et al. 24 Single case report 55 Vision therapy (20 sessions) + prism glasses improved fixations and quality of life in a patient 6 years post-blunt head trauma. Kapoor et al. 25 Two case reports 40 and 50 Oculomotor rehabilitation improved oculomotor function in two middle-aged men with acquired brain injury. Simkhovich et al. 26 Single case report 36 Seven sessions of oculomotor auditory feedback therapy improved convergence from 45 cm to 2 cm in a patient with central scotoma. Gallaway et al. 27 Retrospective cohort study (n=218) mean age: 20.5 years Majority of concussed patients with CI and AI showed improved visual outcomes following vision therapy. Table 1. Summary of Studies Examining the Effect of Vision Therapy and Oculomotor Rehabilitation in Individuals Suffering from Head Injury
Optometry & Visual Performance 132 Volume 14 | Issue 2 | June 2026 jerky pursuit movements. External and internal ocular surface examination were unremarkable. Based on the poor MAF and BAF, low NRA, low esophoria at near, and low MEM results, the patient was diagnosed with accommodative excess.14,15 Based on poor eye movements, she was diagnosed with oculomotor dysfunction.14 Based on the increased symptoms during VOMS, she was diagnosed with vestibulo-ocular dysfunction.14 Optometric vision therapy (OVT), which included accommodative therapy (lens sorting, lens rock, Hart chart, binocular accommodative rock), oculomotor therapy (Brock string, tranaglyphs, vectograms, wall saccades, computer HTS program), and vestibulo-oculo reflex exercises, was recommended to help relax the accommodative excess; improve her fixation, saccadic, and pursuit ability and accuracy; and reduce symptoms. She completed 10 weeks of inoffice optometric vision therapy with 30 minutes of daily home exercises. Vision therapy protocols, based on Scheiman and Wick13 and Scheiman and Rouse,14 consisted of 10 inoffice sessions (40 minutes each) and 30 minutes of daily home exercises. The patient reported improved visual quality after seven sessions and greater comfort with reduced fatigue upon completion. Final outcomes are presented in Table 2. Notably, the monocular and binocular accommodative facilities were improved to 15 and 14 cpm in the OD and OS, respectively. Additionally, the NRA increased to +2.25 D. She used spectacles primarily for driving and prescription sunglasses outdoors. Although she did not return to skating, she successfully enrolled in two academic courses, reported easier reading, and her BIVSS score improved to 31 (59%), with only occasional mild headaches. Case Report 2 A 20-year-old female basketball player sustained a concussion with a concurrent neck injury in 2017 after falling backward. She remained conscious, was hospitalized briefly, and was discharged the same day. In 2018, she reported persistent severe headaches, and MRI revealed gray matter changes. Following physiotherapy, she was cleared to resume sports but experienced a second concussion during a game, leading to disorientation and withdrawal from athletic activity. Post-injury, she was diagnosed with Ehlers-Danlos syndrome, attention-deficit/ hyperactivity disorder, and postural tachycardia Pre-treatment findings Post-treatment findings Right eye Left eye Right eye Left eye First visit since the last concussion 2 years (2021) Previous treatment glasses, PT, CT, medical treatment Uncorrected VA LogMAR 0.52-2 0.4-2 0.5- 0.10 Habitual prescription (D) -1.00 -0.50x170 -1.00 -0.25x010 -0.25 -0.75x175 -0.25 -0.50x010 Cycloplegic refraction (D) pl-0.75x175 -0.25 -0.50x030 Corrected VA 0.00 0.00 0.00 0.00 New Rx for distance (D) -0.50 -0.25x165 -0.25 -0.50x010 CT (dist, Δ) ortho ortho CT (near, Δ) 2 esophoria 2 exophoria Associated phoria (distance, Δ) No prism Associated phoria (near, Δ) No prism AC/A 4/1 NPC (cm) TTN TTN AOA (D) 8 8 8 8 BAF (cycles/ minute) failed + 11 MAF (cycles/ minute) failed + failed + 15 14 MEM (D) plano plano +0.25 +0.25 NRA (D) +1.00 +2.25 PRA (D) -2.75 -2.50 Vergences (distance, Δ) BI: x/8/6 BO: x/20/18 BI: x/8/6 BO: x/20/18 Vergences (near, Δ) BI: x/10/8 BO: x/35/30 BI: x/10/8 BO: x/35/30 VF (cycles/ minute) 13 13 KD (years of age) 10 14 BIVSS 75 31 VOMS increase in symptoms VOR & visual motion No increase in symptoms reported Saccades (Maples) Head movement: 3 Ability: 4 Accuracy: 2 Head movement: 5 Ability: 5 Accuracy: 4 Pursuits (Maples) Head movement: 2 Ability: 4 Accuracy: 2 Head movement: 5 Ability:5 Accuracy: 5 OVT sessions 12 recommended 10 sessions completed Table 2. Summary of the Visual Evaluation Findings Before and After Vision Therapy (Case 1)
Optometry & Visual Performance 133 Volume 14 | Issue 2 | June 2026 syndrome. Her treatment regimen included medications for cardiovascular, neurological, and pain management, including: amitriptyline, sumatriptan, Volidax, bisoprolol, pregabalin, Ajovy, midodrine, Cerazette, Sertral, Xeomin, Decortin, esomeprazole, magnesium, Procoralan, Telfast, Ovixan, and Elvanse. She also received bi-monthly Botox injections for migraines. In January 2019, she reported visual decline and visited an optometrist, where she was prescribed glasses for the first time. Her prescription was -0.75-0.50x015 OD and -0.75-0.50x180 OD. She was prescribed home-based Hart chart exercises, which she reported as mildly beneficial. In May 2023, the patient was referred by her physiotherapist for a binocular vision evaluation due to complaints of visual focusing difficulties at all distances, visual and general fatigue, reading difficulties, photophobia, clumsiness, headaches, migraines, and chronic pain. Examination findings are summarized in Table 3. Cycloplegic refraction (1% cyclopentolate) was +0.25-0.25x010 OD and +0.50-0.75x180 OS. She was prescribed her dry refraction (plano-0.25x180 OD, plano-0.50x010 OS; VA: 0.00 LogMAR) with a +0.75 D near addition due to reduced accommodative amplitude (6.00 D OD; 4.00 D OS; expected: 11.8 D). The patient reported reduced ocular fatigue, improved reading, and decreased clumsiness with the prescription, but she continued to experience unstable distance fixation, photophobia, and headaches. Near point of convergence was to the nose; however, recovery was delayed, with difficulty in regaining fixation. Pursuits were poor and jerky. Cover test revealed orthophoria at distance and 2Δ esophoria at near; associated phoria was unstable on the cross test. Vergence ranges were within normal limits, but vergence facility was reduced for both base-in and base-out. No suppression was reported. Visual fields (HS-Octopus 600) and pupil responses were normal. The King-Devick test score corresponded to an 11-year-old level, and the BIVSS score was 62. During the VOMS, symptoms increased with pursuits, saccades, vestibulo-ocular reflex testing, and visual motion. The Test of Visual Perceptual Skills (TVPS) was partially administered, with low scores in visual discrimination (age equivalent: 9), visual memory (5 years 10 months), and spatial relations (6 years). Anterior and posterior segment findings were unremarkable. Based on the low amplitude of accommodation and increased MEM lag of accommodation, Pre-treatment findings Post-treatment findings Right eye Left eye Right eye Left eye First visit since the last concussion 5 years (2017, 2018) Previous treatment Glasses, PT, medical treatment Uncorrected VA LogMAR 0.00- 0.10+ 0.00 0.00 Habitual prescription (D -0.75 -0.50x015 -0.75 -0.50x180 plano -0.25x010 plano -0.50x025 Cycloplegic refraction (D) +0.25 -0.25x010 +0.50 -0.75x180 Corrected VA 0.00 0.00 0.00 0.00 New Rx for distance (D) plano -0.25x010 plano -0.50x025 New Rx for near (D) +0.75 -0.25x010 +0.75 -0.50x025 +0.75 -0.25x010 +0.75 -0.50x025 CT (distance, Δ) ortho ortho CT (near, Δ) 2 esophoria ortho Associated phoria (distance, Δ) No prism Associated phoria (near, Δ) No prism AC/A 4/1 NPC (cm) TTN TTN AOA (D) 6 4 10 10 BAF (cycles/ minute) Failed +, took 10 sec to clear minus 9 cpm MAF (cycles/ minute) Failed + 11 12 14 MEM (D) +1.00 +0.75 +0.75 +0.25 NRA (D) +1.50 +2.25 PRA (D) -1.25 -2.25 Vergences (distance, Δ) BI: 4/8/4 BO: x/25/12 BI: x/8/6 BO: x/25/20 Vergences (near, Δ) BI: 6/16/12 BO: x/30/25 BI: 6/14/12 BO: x/30/25 VF (cycles/ minute) 6 (slow with base in and base out) 14 KD (yr equiv) 11 13 BIVSS 62 28 VOMS increase in symptoms Saccades, pursuits, VOR, & visual motion Very light increase in dizziness during visual motion Saccades (Maples) Head movement: 3 Ability: 4 Accuracy: 2 Head movement: 5 Ability: 5 Accuracy: 5 Pursuits (Maples) Head movement: 3 Ability: 4 Accuracy: 3 Head movement: 5 Ability: 5 Accuracy: 5 OVT sessions 12 recommended 12 sessions completed Table 3. Summary of Visual Evaluation Findings Before and After Vision Therapy (Case 2)
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