Session 15 - Symposium: Cerebral Visual Impairment (CVI) and Down syndrome, a Multidisciplinary Perspective

Organizer, Moderator:

• Elizabeth Boatwright, MD Internal Medicine-Pediatrics physician, parent to teen daughter with DS+CVI, Co-chair, Down Syndrome Medical Interest Group DS+CVI Workgroup. Boatwrights2@mac.com

Participants: Members of DSMIG DS+CVI Workgroup:

• Arvind Chandna, MD. DO. FRCS. FRCOphth. Consultant Pediatric Ophthalmologist /Senior Clinician Scientist. Chandna SeeLab. Smith Kettlewell Eye Research Institute San Francisco. USA. Translational Clinical Eye Research Centre. (T-CERC-AH). Alder Hey Children’s Hospital. Liverpool. UK. arvind@ski.org
• J Margaret Woodhouse, OBE, PhD, BSc, FSMC, MOptom. Professor, School of Optometry & Vision Sciences, Cardiff University, Maindy Road, Cardiff, CF24 4HQ. woodhouse@cardiff.ac.uk
• Linda Lawrence, MD. Private Practice Ophthalmology, consultant Kansas State School for the Blind. lmlawrencemd@gmail.com
• Lisa Lind, TVI, COMS, MSW. Family Support and Vision Specialist, Down Syndrome Innovations Kansas City, co-chair DSMIG DS+CVI Workgroup. Lisa@kcdsi.org
• Megan DeBoom, BCBA, LBA. Director of Therapeutic Services, Down Syndrome Innovations Kansas City. megan@kcdsi.org

Cerebral/cortical visual impairment (CVI), a brain-based visual condition, is a leading cause of childhood blindness and low vision but remains underdiagnosed in individuals with Down syndrome (DS). While CVI in DS is not well understood, it appears that CVI behaviors are more prevalent in DS than in the general population.

Clear vision is fundamental to feeding, social communication, language acquisition, navigation, motor coordination, cognition, and learning. Children with CVI face significant visual challenges, including fluctuating vision, visual field loss, attention difficulties, impaired visual processing, and reduced contrast sensitivity, all of which can profoundly impact learning and development. Within the DS population, where cognitive delays are common, these CVI-related challenges may be misattributed to DS alone, leading to labels such as "severely affected." Moreover, practitioners' acceptance of a wide developmental range in DS may contribute to the under-recognition of CVI.

This symposium aims to describe our current understanding of CVI (definition, risk factors, and diagnostic approach), and then to explore the complex interplay between CVI and DS, looking at research into higher visual function deficits in DS, case studies, and practical examples of CVI accommodations that may prove useful for individuals with DS.

We hope to highlight the importance of recognizing CVI in individuals with DS using reliable tools for assessment of functional vision to better appreciate the effect on their diverse developmental outcomes, and to incorporate CVI into our understanding of the DS phenotype. Early identification of CVI can significantly enhance access to education and developmental support, particularly for visual learners. Therefore, addressing diagnostic overshadowing, refining screening tools, and developing effective accommodations for CVI in DS are critical for improving outcomes.

1. Cerebral Visual Impairment: A lot is known and much needs to be learnt.

Arvind Chandna.

Cerebral Visual Impairment (CVI) in children is diagnosed through a systematic approach that includes a thorough medical history, assessment of visual function and functional vision, comprehensive eye examination, and relevant investigations, such as brain imaging. An understanding of the development of the eye, brain, and visual pathways is crucial for interpreting the clinical and behavioral manifestations of CVI across the lifespan. Diagnosis and management require a multidisciplinary approach, including long-term follow-up.

While CVI is often the result of brain injury due to birth-related complications, it can also arise from early-onset eye diseases that lead to visual deprivation and abnormal visual development. Increasingly, CVI is recognized in genetic syndromes, such as Down Syndrome, where congenital structural brain and eye abnormalities contribute to the visual deficits characteristic of CVI.

This talk will present the current understanding of the structure-function relationship underlying CVI; findings from a large cohort of children with CVI, including those with Down Syndrome, from a prospective controlled study. These results highlight the complex, multifaceted nature of visual deficits in CVI and emphasize the need for individualized assessments and interventions. A lot is now known and much needs to be learnt.

2. Symptoms / signs indicative of CVI are common in children with Down's syndrome.

Margaret Woodhouse

Background

In our specialist eye care clinic, parents of children with Down's syndrome often describe difficulties with some visual tasks that their children experience. The most common ones are problems negotiating stairs (particularly coming down), steps, kerbs, uneven flooring and changes of flooring, and problems finding an item in an array such as a toy in a pile or box and a parent in a crowd.

Method

We sent a standard inventory (51-item questionnaire designed to elicit symptoms of CVI) to 221 families whose child had attended our clinic over a two-year period. We received and analysed 81 (37%) replies.

Results

ALL children experienced at least one symptom 'often' or 'always', and the percentage of positive replies to the questions ranged from 2% to 75%. 38.3% of the children studied met behavioral criteria for suspected CVI.

Conclusion

It is clear that symptoms suggestive of CVI are very common in children with Down's syndrome. However, it is not clear what contribution the learning disability or developmental delay, as opposed to visual perception difficulty, is contributing to the overall scores. More work is needed to understand this, and to develop a CVI questionnaire that will specifically target children with Down's syndrome.

3. Clinical Applications in CVI and DS

Linda Lawrence MD, Ophthalmologist

Objectives

1. When should we suspect CVI? (cerebral/cortical or brain based visual impairment) in children with Down syndrome (DS)?
2. What is a CVI suspect?
3. In children with DS, CVI now reported in 40%. Is this related to the genetic difference of DS, or risk factors like any other child?

Introduction:

Risk Factors

1. Prenatal history
2. Perinatal history
3. Immediate postnatal history

Clinical examples:

Two adopted girls in same family with DS, one with CVI, one without

1. What is important in the medical history? What are the red flags?
2. What is important in the developmental history?
3. How do we assess, and what are the visual assessment differences?

Take home message:

1. Risk factors for CVI, especially in children with DS
2. What is the ophthalmologist’s role
3. What should the physician do next?
4. How and who do we refer to for (re)habilitation

4. CVI Accommodations in Individuals with DS+CVI, Perspectives from a TVI/COMS and BCBA

Lisa Lind, Megan DeBoom

Our presentation will focus on the accommodations and modifications that support learning and life skills from a functional and therapeutic lens when the diagnosis is Down syndrome and CVI is suspected or confirmed. We will provide case examples of strategies that address issues with mobility, safe and independent travel, fine and gross motor, communication, and behavioral challenges. Research data may lag behind families' motivation to trial and implement learning strategies that support brain based visual issues.

Down Syndrome Innovations is a non-profit agency in Kansas City serving individuals across the lifespan. The therapeutic services team addresses an array of needs including communication concerns, behavioral challenges, life skills, and functional vision. More and more families are questioning their self-advocates' visual needs and searching for answers regarding the intersect between Down syndrome, vision, behavior, and autism.

Strategies as simple to implement as adding reflective tape to stairs can provide the high contrast needed to enable a person with Down syndrome to safely and independently navigate the stairs at home, school, or work. Utilizing a contrasting background and decreasing visual clutter can improve school performance on tasks such as puzzles or math manipulatives. Finally, providing visual breaks and addressing sensory needs can decrease time off task and support success in the workplace or school versus managing the issue as a behavioral challenge. Our emphasis from a Teacher of the Visually Impaired and Behavioral Analyst perspective will be on taking a proactive approach to intervention that can improve outcomes and help lead towards research on best evidence based practice.