Appendix B

Differential Criteria for Assessment and Instruction of Needs Resulting From Cortical Visual Impairment

Christine Roman-Lantzy

Children can have visual impairment because of damage to the structures of the eye or because of damage or changes in the visual pathways or processing centers of the brain. Recognition of the need for assessment and education of students who have ocular forms of visual impairment has long been established. The population of students who have brain-based forms of visual impairment is a relatively new field of study. The American Foundation for the Blind published its first textbook designed to describe assessment and instructional techniques for students with cortical visual impairment (CVI) in 2007. The incidence of children with visual impairment because of damage or structural differences in the brain has risen dramatically as medical interventions for critically ill infants, children, and those who have experienced trauma, have improved. It is likely that this trend toward increasing numbers of children who have CVI will continue. Medical interventions continue to advance in favor of survivability of the most fragile infants and children (Colenbrander, 2010); with this survivability, there comes an increased population of children with significant disabilities, including CVI.

It is important to explicate the terminology used to describe children who have visual impairment because of brain damage or structural differences of the brain. The terms “cortical visual impairment” and “cerebral visual impairment” have been used interchangeably, but these terms do not always refer to precisely the same phenomenon. A multidisciplinary group of professionals authored a paper, “Statement on Cortical Visual Impairment” (Roman et al., 2009), in which cortical visual impairment is defined in the following way:

One concern of professionals in the field of education of students with visual impairments is to establish a standard definition of CVI. Accordingly, the purpose of this article is to clarify the differences between children who qualify for services from vision educators and those who have visual processing difficulties that are not considered visual impairment. Our perspective is that all children who have CVI should be classified as visually impaired and receive the necessary services, regardless of the severity of the degree of CVI or additional disabilities. A child with CVI is distinguished from a child with learning disabilities or developmental disabilities by the following criteria: (1) an eye examination that cannot fully explain the child’s use of vision; (2) a history or presence of neurological problems, even when the child’s brain-imaging studies may appear normal (Dutton, 2008); and (3) the presence of the behavioral or visual responses that are collectively associated with CVI (p. 69).

Cerebral visual impairment is sometimes defined in terms of the location of the brain damage rather than in the functional visual responses of the individual. For example, Soul and Matsuba (2010) describe cerebral visual impairment as, “visual impairment owing to abnormal development of, or injury to, the optic radiations, striate cortex, and peristriate cortex regions” (p. 20). These differences in terminology leave some to wonder if these conditions describe the same or different groups of individuals who are both labeled “CVI.”

There may also be some confusion about the “profile” of an individual with CVI. The criteria used to diagnose CVI can apply to a broad group of individuals, and it is important that professionals refrain from identifying children with CVI in a stereotypic manner. It is incorrect to consider CVI as a condition strictly associated with premature birth. It is incorrect to think of all children with CVI as having severe and profound additional disabilities. It is incorrect to consider CVI only as a condition that occurs in infants. It is incorrect to believe that children with CVI cannot have co-existing ocular conditions (Roman-Lantzy & Lantzy, 2010). It is incorrect to view all children with CVI as being too impaired to learn to read, to attend regular education, or to learn to move independently in their environments. Individuals with CVI are a highly diverse group, but their CVI status and educational needs are not as elusive as some may suggest. There is a systematic methodology that can be used to guide the needs of individuals who have CVI.

The medical conditions that cause CVI can occur as prenatal, perinatal, or traumatic events. CVI is commonly considered a condition that occurs because of conditions that include pre or perinatal asphyxia, periventricular leukomalacia, grade IV intraventricular hemorrhage, perinatal stroke, infection, or structural differences of the brain. However, CVI can also occur in typically developing individuals who experience an accident or other trauma that affects the visual pathways or processing centers of the brain. Clearly, it is important for physicians to understand the site of the brain damage; however, knowing the specific etiology does not directly lead to diagnosis of CVI or to an understanding of how CVI affects the individual. The key to understanding these factors is to investigate the potential presence of the visual and behavioral characteristics associated with CVI. These characteristics include color preference, increased attention to movement, difficulties with visual complexity, visual latency, atypical visual field responses, difficulties with visual novelty, difficulties with distance viewing, atypical visual motor responses, atypical visual reflex responses, and light gazing.

The CVI Range© (Roman-Lantzy, 2007) is a functional vision assessment designed to determine the affect of CVI on a 0-10 scale. The CVI Range incorporates the results of two testing methods to derive a composite set of scores, or the “range.” The CVI Range test items are designed to investigate the extent of each CVI characteristic in functional, routine tasks that are based on the individual’s interests, age, and abilities. Information is gathered through an interview with an informed adult (generally the parent), observation of the individual, and direct face-to-face interactions. The CVI Range was found to have sound psychometric properties and is a highly reliable and valid assessment of the extent of affect of CVI (Newcomb, 2011). The CVI Range is used to evaluate children who are approximately 6 months of age through early adulthood. It can be used reliably with individuals who span all levels of ability or disability. The CVI Range is only sensitive to the characteristics of CVI, and therefore, a profile emerges only when the individual actually has CVI. In other words, it does not produce “false positives” in children who have autism spectrum disorders, learning disabilities, or other disorders. Because of this finding, The CVI Range can be used to assist in the diagnostic process and may help confirm the presence of CVI.

The intention of The CVI Range is to identify a score along the 0-10 continuum and to use the discreet score or “level” of CVI to accurately design instructional methods, materials, and environments that promote access to information through the visual channel. It is critical that the accommodations match the score obtained on The CVI Range. This score provides a framework of the way each CVI characteristic is applied to the functional, academic, and leisure activities of the day. It is important to use the specific “CVI-characteristics formula” across the routines of the day and to avoid thinking of interventions for children with CVI as, “vision time.”

Medical identification or diagnosis of CVI in children continues to be a somewhat elusive process. Unlike retinopathy of prematurity, there is no established medical protocol used to screen children who are most at risk for CVI. The condition is often diagnosed long after parents express concerns about their child’s lack of eye contact, difficulties following or tracking an object, or somehow seeming blind (Roman-Lantzy & Lantzy, 2010). Often the eye exam is either normal or there are minor changes in the optic nerve. Strabismus was diagnosed in nearly half of the individuals in the Pediatric View study (2010). If concerns about vision persist, the physician may suggest a visually evoked potential/response test or an MRI. Unfortunately, these tests are not able to accurately diagnose CVI. It is possible that after all the clinical and technological methods have been applied, CVI is diagnosed as a “rule out” condition. This process can take months or even years. Educators should not wait for the formal diagnosis. It is critical that a child who has (a) an eye exam that does not explain the child’s functional use of vision, (b) a history of neurological impairment, and (c) the characteristic visual and behavioral traits of CVI receives intervention in a timely manner. Teachers of students who have visual impairments can use The CVI Range or other methodology to determine if the CVI characteristics are present. If the child does have a functional CVI profile, the educator can use the assessment information to support the finding that the child’s visual performance adversely affects learning and, therefore, educationally qualifies for services.

There is some evidence to support the principle that CVI-specific interventions can facilitate the improvement, or habilitation of functional vision in individuals who have CVI. Roman-Lantzy and Lantzy (2010) reported that significant improvement in functional vision as measured by The CVI Range is achievable and not simply a function of maturation or age. Their study presents a sample of changes in CVI Range scores in 77 children. The cohort consisted of children who spanned a wide range of ages, degree of additional disability, and medical etiologies. Results of the study showed that improvements in functional vision were unrelated to age, cause of CVI, or even whether or not the individual had a teacher of students with visual impairments. However, all of these 77 individuals with CVI were provided with adaptations to environments and materials in accordance with their CVI Range scores obtained in regular assessment sessions. Although a cause and effect relationship cannot be established, the fact that 88% of the individuals initially scored 3 or less at the initial assessment and 95% scored 7 or above at the last assessment (within an average of 3.7 years) demonstrates a significant correlation between CVI specific interventions and outcomes of improved functional vision.

Clearly, additional evidence must be obtained to verify the best practices for assessing individuals who have CVI. It is likely that collaboration between medical and educational research will be a necessary component of this task. Ashok Panigrahy, M.D., and Christine Roman-Lantzy, Ph.D., are currently examining the relationship between changes in the visual processing areas in the brain using functional MRI (fMRI) technology and improvements in functional vision measured by CVI Range scores. fMRI is based on the same technology as MRI (magnetic resonance imaging), a noninvasive test that uses a strong magnetic field and radio waves to create detailed images of the body. Instead of creating images of organs and tissues like MRI, fMRI looks at blood flow in the brain to detect areas of activity. These changes in blood flow, which are captured on a computer, help physicians and researchers understand how the brain is functioning. Panigrahy and Roman-Lantzy are using fMRI to examine the quality and quantity of changes in areas of the brain designated for visual processing and then comparing these changes to the improvements in the 10 characteristic behaviors associated with CVI. Panigrahy and Roman-Lantzy hypothesize that there will be evidence to support the belief that specific improvements in functional vision as measured by The CVI Range will be associated with new brain structures that process vision. This study will also include a control group of individuals with CVI who have received a non-CVI specific intervention.

CVI is the leading cause of visual impairment in children in the developed world (Dutton & Bax, 2010). Unfortunately, organized methods to diagnose CVI and to provide interventions for individuals with CVI are in their infancy. It is critical that researchers, clinicians, educators, and parents contribute their special expertise to facilitate greater understanding and more effective practices on behalf of children who have CVI. The insights and efforts of all members on this team are essential.

References

Colenbrander, A. (2010). Towards the development of a classification of vision-related functioning – A potential framework. In G. N. Dutton & M. Bax (Eds.), Visual impairment in children due to damage to the brain (pp. 282-294). London: Mac Keith Press.

Dutton, G. N. (2008). “Dorsal stream dysfunction and dorsal stream dysfunction plus”: A potential classification for perceptual visual impairment in the context of cerebral visual impairment? Developmental Medicine and Child Neurology, 10, 1–2.

Dutton, G. N., & Bax, M. (Eds). (2010). Visual impairment in children due to damage to the brain. London: Mac Keith Press.

Newcomb, S. (2011). Functional vision assessment for children with cortical visual impairment. Deaf-Blind Perspectives, 18. Retrieved from http://nationaldb.org/dbp/current.htm#cvi.

Roman, C., Baker-Nobles, L., Dutton, G. N., Luiselli, T. E., Flener, B. S., Jan, J. E., … Nielsen, A. S. (2010). Statement on cortical visual impairment. Journal of Visual Impairment & Blindness, 104, 69-72.

Roman-Lantzy, C. (2007). Cortical visual impairment: An approach to assessment and intervention. New York: American Foundation for the Blind

Roman-Lantzy, C. A., & Lantzy, A. (2010). Outcomes and opportunities: A study of children with cortical visual impairment. Journal of Visual Impairment & Blindness, 104, 649-653.

Soul, J., & Matsuba, C. (2010). Common aetiologies of cerebral visual impairment. In G. N. Dutton & M. Bax (Eds.), Visual impairment in children due to damage to the brain (pp. 20-26). London: Mac Keith Press.

Christine Roman-Lantzy, Ph.D., is the Director of The Pediatric View Program at The Western Pennsylvania Hospital in Pittsburgh, PA. She has lectured extensively regarding the CVI educational materials she has developed.