Pediatric Cortical Visual Impairment

Save the date, July 8-9, 2016 for the Annual American Conference on Pediatric Cortical Visual Impairment (PCVI), being held at the Marriott Regency in Omaha.  The meeting is under the auspices of the Children’s Hospital & Medical Center of Omaha.  I’ve heard wonderful things about the meeting form colleagues Dr. Kerri Dietz Pillen and Dr. Dominick Maino.

Children's Hospital Omaha

As stated in their program flyer, the American Conference on PCVI brings together occupational therapists, ophthalmologists, optometrists, teachers of the visually impaired, neurologists, pediatric intensivists, physiatrists and parents to increase interdisciplinary understanding of cortical visual impairment in children.

The conference objectives this year are for participants to be able to:

  • Examine the CVI inventory developed by Professor Dutton and discuss its applicability in different cultures and rural vs. urban settings.  (I blogged previously about some of Professor Dutton’s work.)
  •  Identify strategies for implementing CVI interventions within the context of an educational curriculum.
  • Discuss the role of the optometrist in optimizing outcomes for children with CVI. Participants will be able to describe the ophthalmologist’s responsibilities as part of the multidisciplinary team for children with cortical visual impairment.
  • Discuss a rationale for removing barriers which may restrict
    positive outcomes for children and youth with CVI and complex communication needs.
  • Identify strategies that address the language, vision, and learning of these children in ways that directly impact daily activities, participation, the environment and ultimately their ability to live productive, fulfilling lives as children and adults.
  • Describe visual function and specific therapies for children withCVI.
  • Participants will learn how comprehensive services are provided to children ages birth-five who have a diagnosis of CVI including partnering with the medical and early intervention community, the use of a state-wide screening tool, O&M services, home-based and preschool curriculum and state wide initiatives.
  • Identify the CVI characteristic most associated with difficulties in social skill acquisition and strategies that can facilitate increased social competence in individuals with CVI.
  • Review current research efforts related to CVI via poster presentations.
  • Discuss future scientific research opportunities.
  • Discuss collaborative opportunities for shared problem-solving for parents of children with CVI.
  • Describe the number and profile of children with CVI in Scotland and highlight the collaborative support mechanisms that have been built around an integrated health, education and social work policy.
  • Discuss the optometric management of CVI patients.
  • Describe how to use the “What’s the Complexity Framework” to lead educational teams in planning appropriate school activities and schedules for students with CVI.
  • Identify the scope and sequence of O&M knowledge and skills in the preschool through kindergarten years.
  • Identify strategies to support age appropriate concept development and travel skill for the Pre-K child with pediatric CVI.
  • Review pearls for changing practice and identify opportunities for future education.

Children's Hospital Umbrellas

 The course director is Richard H. Legge, M.D., a pediatric neuro-ophthalmologist who is an assistant professor of Ophthalmology and Visual Sciences at UNMC College of Medicine.  Two optometrists who are part of the course faculty are Nicole Hooper, O.D., Visiting Assistant Professor University at the Houston College of Optometry, and John P. Lowery, O.D., M.Ed., Professor and Chief of Pediatrics at Pacific University College of Optometry.

New to this year’s meeting is a scientific poster session.  You can submit an abstract of no more than 200 words, on any content related to CVI, to solsen@childrensomaha.org.  Questions about the meeting can be directed to 402-955-6070.

A World of Visual Uncertainty

Visual Uncertainty

Nicola McDowell is co-author of a paper published in Vision Development & Rehabilitation that provided a phenomenal review of posterior parietal visual dysfunction.  Perhaps it would have gained even more traction had the article been entitled: “Living in a World of Visual Uncertainty”.

I was introduced to the phenomenal resource of CVI Scotland, and the extensive applications of Cortical Visual Impairment theory and practice by Dr. Barry Kran.

CVI Scotland Logo

Dr. Kran authored a guest blog on CVI Scotland last week, and an editorial comment made during the course of a companion interview jumped out at me:

Screen Shot 2018-02-08 at 9.00.28 AMLet that last thought percolate:  The diagnosis of CVI may be appropriate in some children with good to excellent acuity, but who are not able to navigate space and/or read without masking or enlargement.  Trust me.  Its implications are profound.

Posterior Cortical Atrophy Revisited

If you’re having trouble recalling Part 1 of this topic, there is a good reason.  It has been a year and a half since I blogged about Paul and his challenges with PCA.  As anticipated, Paul has experienced further degenerative changes to occipital and parietal lobe function.  He still continues to express himself well, to the point of being able to present his weekly professional webinars, though his wife has to handle all the operational elements of the slide show.  Paul’s wife accompanies him to every therapy session and progress evaluation in our office, and he is either unaware of or denies the difficulties that she describes, which includes very basic activities of daily living such as dressing himself properly.

The compromise in Paul’s parietal lobe function is evident directly in judging visual space and visual motor planning.  A basic function such as inserting a letter into a mail slot has become an adventure.

His wife has implored us to continue working with Paul, and the spotlight of our attention has now turned more toward visual judgement and visual guidance of motor movement through the parietal lobe.  We will be doing alot of work with elementary parquetry blocks, and with inter-hemispheric functions such as infinity walk.  Bear in mind that in working with senior citizens such as Paul, we are going back in time to where he was first learning to execute these functions and trying to salvage as much as possible.  In other words, there is no illusion that we will reverse the degenerative process, and we’re not interested in “teaching an old dog new tricks” as much as we are in helping to mitigate the functional effects of PCA degenerative changes.  Our therapy sessions therefore look more and more like what one would undertake in working with a young child struggling with the development of visual cognition, and our suite of activities will be drawn increasingly from the visual spatial procedures catalogued by Drs. Harry Wachs and Serena Wieder.

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Paul has now developed cataracts in both eyes, no surprise at age 72.  The ophthalmic literature is suggestive that cataract surgery may in some instances improve cognitive function, but Paul’s wife and I agree that elective surgery is something we don’t want to put him through now.  When I dilated is pupils last week with Paremyd, you can see that his pupil dilated asymmetrically.  Anecdotally I see this fairly often with Paremyd in seniors with cognitive impairment, and though it’s speculative on my part I wonder if the hydroxyamphetamine component of the drug might have something to do with that.  Paul also has scattered visual field dropout on FDT Screening, but this may be secondary to the cataract and will not influence our activities with him in vision therapy.

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We will continue to work on reading readiness skills with Paul, such as modified Hart Charts with ample spacing, and the TOSWRF (Test of Silent Word Reading Fluency) modified as a therapy procedure for sequential tracking and word recognition.  We enlarge print size and increase spacing as required, but always try to challenge Paul to handle more crowded or complex fields as he is able.

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When he writes, Paul has developed a significant slant.  We believe this is due in part to his PCA, and in part due to a decompensating vertical phoria (which may be interrelated).  We recently incorporated vertical prism into his near Rx, and anticipate this will help him further with trying to salvage reading and copying skills, and to better track music notes in line when he plays guitar.

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Reading, Crowding, and Posterior Cortical Atrophy

Paul is a retired health care professional who has early phases of Alzheimer’s Disease (AD), but in an atypical presentation known as Posterior Cortical Atrophy (PCA).  In typical  AD, the neurodegenerative process begins with atrophy of the hippocampal regions of the brain and disrupts memory.  In contrast, PCA begins with atrophy in the posterior regions typically involving the parietal and occipital regions of the brain.

PCA vs. AD

PCA escapes early detection because the patient is still so sharp in terms of memory, receptive language, and expressive language.  The earliest signs are related to visual impairment, though not impairment in visual acuity or visual field – as the term is conventionally used.

In 2010 I blogged about Lillian, a case of PCA that Oliver Sacks popularized in The Mind’s Eye.  As with Lillian, it is sad to see Paul – a once vital practitioner and musician – progressively diminish in his visual abilities.  Paul suffered a TIA while undergoing heart surgery in 2010, and much of the focus since that time has been on trying to help him regain driving skills, and track well enough to read accurately.

While Paul’s visual acuity and visual fields have remained relatively normal, his visual tracking and visual representation of space has not improved.  We have been successful in helping his binocular vision, which had begun to unravel, but not as successful to date in helping him with his visual cognition.

A recent paper in Neuropsychologia links progressive deterioration in reading to the neurodegenerative changes in PCA, with crowding as a significant factor.  Scanning in the horizontal plane becomes particularly problematic.  The compensation for crowding is larger size font, and well-spaced letters.  Reading through a typoscope with a window; blowing up print size on eReaders; experimenting further with color and contrast are all on the agenda.  While we are going to still work in neuro-optometric rehabilitation on maximizing Paul’s residual visual abilities, his is a case in which we’ll have to continue swimming upstream with increasing vigor.

 

Delayed Visual Maturation: A Visual Inattention Problem

I’ve been fortunate now, on two consecutive days, to get a heads up from sharp New Jersey primary care O.D. colleagues who keep an eye out for articles of common interest.  Yesterday it was new evidence based support for amblyopia therapy.

Today Dr. Charlie Fitzpatrick sent the link to an article from Expert Review in Ophthalmology on delayed visual maturation (DVM) as a problem in visual inattention.  In a nutshell, the article describes what those of us in Pediatric Optometry have dealt with as cortical blindness or cortical visual impairment (CVI). There is no apparent reason why these infants don’t respond visually.  That is, they generally respond normally to retinal tests such as ERG, subcortical tests such as OKN, and visual cortical measures such as VEP.  The distinction might be made that DVM is a form of CVI that resolves over time.

This article notes that the defining characteristic of DVM is an inability to fixate and follow a target.  The authors do a nice job subdividing DVM into four categories:

Type 1 DVM: Visual fixation, attention, and tracking eventually develop, but these infants are at higher risk for learning disabilities and attention disorders.

Type II DVM: Resolution of visual delay is often slower and more incomplete than in Type I.  There is often seizure activity associated with cognitive disorders, and visual responses often improve as seizures are treated.  Hypoxia to the extrageniculostriate visual system is often involved.

Type III DVM: Infants in this category have associated congenital nystagmus and albinism.  Their vision starts to improve later, and to a lesser degree.

Type IV DVM: Infants in this classification include severe ocular disorders such as retinal dystrophies, optic nerve hypoplasia, and macular coloboma.

There are several interesting implications from this review:

1) DVM is a symptom common to a variety of neurologic abnormalities in which efferent and afferent visual pathways are largely intact.  The symptom itself is a problem of visual inattention that exists on a continuum in terms the time course of delayed development, and the degree to which visual attention is ultimately developed.

2) Top-down visual attention derives from multiple areas outside of the visual cortex, consisting primarily of an anterior and posterior network.  The anterior network includes he frontal and supplemental eye fields of the frontal cortex, as well globus pallidus, caudate, putamen, parts of the thalamus.  The posterior system consists of parietal cortex, superior colliculus, and pulvinar.  It is likely that visual inattention involves delayed maturation of, or damage to this network.

3) We are used to thinking of the concept of visual neglect in terms of acquired brain injury that results in inattention to a select region of the visual field.  A better understanding of DVM as total visual neglect, and its resolution, in those cases where fixation and following ultimately develops, may provide a better understanding of visual inattention with other populations.

An ophthalmologist who functions more like a developmental/behavioral optometrist, Lea Hyvarinen, has material that complements this article.  Here is a nice lecture she gave in San Francisco in 2003 on the assessment of CVI, and Dr. Hyvarinen has also presented on the trans-disciplinary nature of assessment.  A conference in which she participated last year highlighted these complexities.  Of particular interest will be her blog, Dr. Lea & Children’s Vision.

– Leonard J. Press, O.D., FCOVD, FAAO

 

Insights From ISA/AAPOS 2018

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Held in March of this year in Washington, D.C., the 2018 annual meeting of the International Strabismological Association and the American Association for Pediatric Ophthalmology and Strabismus included a variety of lectures, papers, and posters of  interest.

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Here are some highlights (with active hyperlinks preceding each title):

  • The Bielschowsky Lecture – Accommodation and Convergence: Ratios, Linkages, Styles, and Mental Somersaults
  • Paper 3: Impaired Motion Perception in the Fellow Eye of Amblyopic Children is Related to Abnormal Binocular Function
  • Paper 7: Effects of Immersive Virtual Reality Viewing on Young Children: Visuomotor Function, Postural Stability and Visually-Induced Motion Sickness
  • Workshop 17: Reading Difficulties and the Pediatric Ophthalmologist
  • Poster 33: Re-Reading the Same Line in Intermittent Exotropia is Related to the Saccadic Disconjugacy.  (Difficulty of reading is a typical symptom of intermittent exotropia (IXT) and is coupled with re-reading the same line.)
  • Poster 57: Attitudes Concerning Cortical Visual Impairment Among Pediatric Ophthalmologists and Teachers of the Visually Impaired
  • Poster 161: Optic Nerve Morphology in Normal Children: A Validation Study
  • Poster 181: Baltimore Reading and Eye Disease Study (BREDS): Two-Year Results on Compliance with Eyeglass Usage
  • Poster 214: What is Amblyopia? A Primary Care Physician’s Perspective
  • Poster 217: Boston Amblyopia Study 1: Complete Resolution of Subthreshold Amblyopia with Standard Clinical Treatment
  • Poster 218: Boston Amblyopia Study 2: Treatment Outcomes in Patients with Asymmetric, Bilateral Amblyopia
  • Poster 227: Influence of Orthokeratology Lens on Axial length Elongation and Myopic Progression in Childhood Myopia
  • Poster 228: A Three Year Follow-Up Study of Atropine Treatment for Progressive Myopia in Europeans

CVI: Visuoperceptive & Visuocognitive Disorders

What does the acronym “CVI” represent?  At one time it stood for Cortical Visual Impairment, but it is now more widely referred to as Cerebral Visual Impairment.  It’s about time that change occurred.

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A rose by another name?  Not at all.  In fact the transition to the more diffuse notion of cerebral rather than cortical addresses an age old question I had.  How could a child with CVI have a normal pattern VEP response?  The answer, by definition,  had to be that the impairment resided in areas of visual cortex other than V1 – which reminds us how much there is to vision in the visual pathways beyond visual acuity.

 

A book that was co-authored last year by Professors Zihl and Dutton captures the essence of CVI in its subtitle of visuoperceptive and visuocognitive disorders.

Dutton Cover

Here are some nice sound bites from the book:

  1. To a major extent, vision is a skills that depends on learning and use, just as other skills such as walking or talking.
  2. The field of attention in young children is not fully developed, and they may therefore ignore peripheral stimuli particularly when they appear simultaneously in both hemi-fields.
  3. Reading requires various functional prerequisites including visual, oculomotor, and cognitive functions that facilitate reception, processing, and understanding of spatially distributed visual-verbal information.
  4. Sensitivity to word visibility increases between 7 and 12 years of age, which is associated with developmental changes in activation in left occipital-parietal regions.
  5. Vergence and accommodation are best understood as calibration and recalibration processes to various fixation distances, which are controlled by neural structures in the brainstem, cerebellum and cerebral cortex and in addition are influenced by attention and the intention of visual information processing.
  6. It is possible to have CVI with near normal visual acuity, and crowding can occur due to a variety of visual interferences.  Visual crowding due to CVI can impair reading.  For children who are hyperopic or those with impaired accommodation, positive lenses both magnify text and allow it to be read closer to the eyes, bringing about additional magnification due to proximity.  This can in turn reduce crowding of text on the printed page, which can enhance access to the printed word.  Correction of only one or two diopters of hyperopia can benefit some children with CVI.

What’s App-enning?

PinterestNice array of apps on Pinterest specific to Visual Impairment/Vision Therapy.  Here is a new one in the iTunes store that hasn’t been pinned yet, but looks good for children with cortical visual impairment.  It’s called Tap-n-See Zoo.  But the big news for this evening is that the Vision Tap: Vision Therapy App, by Tap in Apps (sounds like Dr. Seuss!) is back on the market.  Originally intro’d in 2012, the new version was developed by Kevin Sullivan whose father is Dr. Joe Sullivan, a colleague in Kansas.

Vision Tap 1Vision Tap 2Vision Tap 4 Vision Tap 6vision tap 7vision tap 9

Vision Tap 3

Can An Eye Examination Be Worse Than Useless?

visual-impairment-in-children-due-to-damage-to-the-brain-clinics-in-developmental-medicineBefore you rush to judgement about the title, because it’s intentionally provocative, let me re-assure you that it isn’t my concept.  It jumped out and grabbed me by the eyes from several different vantage points as I was reading this incredible volume of Clinics in Developmental Medicine.  The idea comes from chapter 10, written by Roger D. Freeman, M.D., who practices in a children’s hospital in Vancouver.  Regarding psychiatric considerations in cortical visual impairment, Dr. Freeman writes: “Because of great variability and complexity, a routine psychiatric evaluation by a clinician unfamiliar with CVI may be worse than useless; the delineation of biological, psychological, or social factors that constitute the basis for meaningful psychiatric formulations of problems may be severely limited or distorted.”

Now here’s the payoff.  Freeman continues by applying this to vision: “In children with multidisability, it is not uncommon for a normal eye examination to be mistakenly taken by others as proof of normal visual function.  Such beliefs are then difficult to dislodge and visual behavior is not appropriately interpreted.”

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I was reminded of this yesterday during a seminar presentation to a group of professionals comprised largely of Occupational Therapists at a very lovely Embassy Suites Hotel in Blue Ash, Ohio, just outside Cincinnati.  Running through the center of the hotel is a lush garden with a stream containing fish located subtly enough that you don’t really notice unless you’re looking for them.

I now begin my seminars with an open-ended question:  “What is normal vision?”  By agreeing that it is something beyond 20/20 eyesight and healthy eyes, we open the discussion to a much deeper appreciation of the complexities of the visual process.  This quickly leads to the consideration about the extent to which eye examinations probe pertinent visual functions in the populations with whom we’re principally dealing: learning problems, dyslexia, developmental delay, autism, and acquired brain injury.

Exam

All the OTs (and PTs) present nodded their heads in the affirmative that the report form above is what they typically get back from pediatric ophthalmologists regarding examinations.  In a few words, 20/20 acuity with each eye, normal eye exam, no treatment indicated.  I then put up a slide that shows a joint report from an OT and PT in my town, indicating that a child has inefficient ocular motor skills, issues with visual attention, and intense fatigue following a few minutes of visual tasks.  The report stipulates that this child should be evaluated by a developmental optometrist.  They have learned that when the parent is given a false sense of security that visual function is normal because the eye examination is normal, the eye examination is worse than useless.

A Developmental and Behavioral Ophthalmologist

Great presentation this afternoon at the COVD Annual Meeting by Lea Hyvarinen, M.D., from Finland, my all-time favorite developmental/behavioral ophthalmologist.  Alright, she may be the world’s only developmental/behavioral ophthalmologist, but she is so good at what she does that it would be wonderful if she could influence her colleagues in the United States to follow suit.

A very clever test that she reviewed for visual tracking of infants and toddlers is Pepi – The Dalmatian in Motion.  Our colleague, Dominick Maino, blogged about Pepi a few years ago.

Dr. Hyvarinen’s presentation was titled: Early Detection, Assessment and Intervention of Problems in Visual Development: Optometrists’ and rehabilitation ophthalmologists’ role in the transdisciplinary team work.  She wrote a wonderful book that captures her approach that you can obtain here.

You can obtain more information on her subject matter through these online resources:

Quality of Incoming Visual Information

Dr. Hyvarinen’s Blog

Cortical Visual Impairment

Lea Hyvarinen’s Homepage

VisionHelp Blog on Dr. Hyvarinen