Cortical Visual Impairment (CVI) is a type of bilateral visual impairment which is caused by damage to the brain rather than damage to the eyes. To put it simply, the eyes work fine but the brain cannot interpret what it is seeing. A child with CVI should be diagnosed, assessed and treated differently than one who has an ocular-based visual impairment. CVI is now the leading cause of visual impairment in the United States 1 and other developed countries around the world.
In this video, Early Childhood Vision Consultant, Tara Tompai, defines Cortical Visual Impairment. Tara Tompai is a Perkins-Roman CVI Range Endorsee.
There is no treatment or cure for Cortical Visual Impairment but it may be possible to see improvement in functional vision when the right CVI interventions are put into place.
“What it means to be born visually impaired today has evolved tremendously and it has more to do with our understanding of the brain than it does with the eye.”
Dr. Lotfi Merabet, Associate Professor of Ophthalmology at Harvard Medical School and Director at The Laboratory for Visual Neuroplasticity at Massachusetts Eye and Ear.
Understanding CVI
People of all ages can be affected by CVI, including infants, young children, teenagers and adults. It is a serious lifelong condition that poses potential dangers such as tripping and falling or the inability to see oncoming traffic. Children who have CVI often struggle academically and require personalized CVI adaptations to make their environment visually accessible. They can benefit greatly from the help of a Teacher of the Visually Impaired (TVI) and an Orientation and Mobility Specialist.
Due to brain injury, children with CVI often suffer additional neurological conditions and multiple disabilities. The event that damages visual pathways resulting in CVI may also contribute to cognitive and/or motor disfunction. In addition, other areas of the brain, the retina, optic nerves or chiasm may be affected too. 2.
“Cortical visual impairment is defined as bilateral visual impairment, involving acuity and/or higher visual functions, such as visual motor planning, due to posterior visual pathway disease. It is one component of a global neurologic process.”
A Primer on Cortical Visual Impairment by Sharon S. Lehman, MD, Review of Ophthalmology
How to Assess Functional Vision and The 10 Characteristics of CVI
Several visual functions may be compromised in children who have Cortical Visual Impairment, such as the ability to recognize objects and faces, process motion, visual memory, orientation, visual spatial perception and simultaneous perception. 3
Often, children who have CVI exhibit atypical visual behaviors, such as difficulty with complexity or latency. These unusual visual behaviors are outlined as The 10 Characteristics Cortical Visual Impairment, according to Christine Roman-Lantzy, PhD in her book Cortical Visual Impairment: An Approach to Assessment and Intervention.
The 10 Characteristics of Cortical Visual Impairment (CVI) are:
- Color preference
- Need for movement
- Need for light
- Visual latency
- Visual field preferences
- Difficulty with complexity
- Difficulty with distance viewing
- Difficulty with visual novelty
- Absence of visually guided reach
- Atypical visual reflex responses
Not all children with CVI are alike and each child requires a personalized approach based on his or her specific needs and visual deficits. In order to assess your child’s use of functional vision and identify the appropriate CVI interventions, it is recommended to obtain a CVI Range assessment by a Perkins-Roman CVI Range® Endorsee.
What causes Cortical Visual Impairment?
The most common causes associated with Cortical Visual Impairment are as follows 4:
- perinatal hypoxia
- prematurity
- hydrocephalus
- structural central nervous system abnormalities
- seizures
In my family’s case, our daughter suffered a traumatic brain injury in utero which caused her to have CVI.
How to diagnose CVI
If you suspect your child has Cortical Visual Impairment due to a brain injury or other neurological condition, it is important to seek help from a medical doctor. CVI is usually diagnosed by an ophthalmologist or neurologist. If your medical practitioner is not familiar with CVI, you may consider pointing them to the online resource pcvis.vision, a very informative website by the Pediatric Cortical Visual Impairment Society.
- Hatton DD, Schweitz E, Boyer B, Rychwalski P. Babies Count: The national registry for children with visual impairments, birth to 3 years. J AAPOS. 2007;11:351–5.[↩]
- Good WV, Jan JE, de Sa L, Barkovich AJ, Groenveld M, Hoyt CS., (1994). Cortical visual impairment in children. Survey of Ophthalmology, 38(4), 351-364.[↩]
- Swaminathan, M. (2011). Cortical visual impairment in children — A new challenge for the future? Oman Journal of Ophthalmology, 4(1), 1–2. http://doi.org/10.4103/0974-620X.77654[↩]
- Khetpal V, Donahue SP. Cortical visual impairment: Etiology, associated findings, and prognosis in a tertiary care setting. J AAPOS 2007;11(3):235-239.[↩]
Cindy has a deep interest in Cortical Visual Impairment (CVI) and is currently studying Early Childhood Education. She focuses most of her time on her energetic daughter: playing, cuddling and helping to make her world visually accessible. Cindy holds a degree in Marketing and has worked in the not-for-profit sector for many years.