Cortical Visual Impairment 101

I recently attended a conference so I could educate myself on Cortical Visual Impairment, one of the diagnoses my son has. It was so enlightening and revolutionary, and add in a big heap of mom guilt. When you have a child with multiple disabilities, it can be tough to decide which one to prioritize or focus on. After this conference and digesting what I learned there, I am definitely moving CVI to the top of the list. The following information is from Dr. Christine Roman-Lantzky, one of the leading researchers and specialists in CVI. I’m not a doctor, nor do I play one on the Internet. Please consult your child’s medical team with specific concerns.

So without further ado….here is CVI 101, a brief overview that hopefully will help parents navigate this new world.

a-team-approach-to-cvi-in-schools-PDF booklet, download and print to share with your child’s team.

What is Cortical Visual Impairment (CVI)?

There are two types of visual impairments–those that eye based (a problem with the actual eye) and those that are brain based (a problem with the brain). CVI is brain based; there is damage or atypical structures in the visual pathways. Visual processing is compromised to varying degrees. The eyes get the image and the brain perceives it, however it cannot categorize the information or sort the information. The brain cannot label it or put meaning to it. This is why glasses do not fix the problem. Children may look at objects, frequently. Looking at an item does NOT mean that they are able to interpret it.

Causes

Including, but not limited to: asphyxia, hypoxia (a lack of sufficient oxygen in the body’s blood cells), or ischemia (not enough blood supply to the brain), all of which may occur during the birth process; developmental brain defects; head injury; seizures,  hydrocephalus (when the cerebrospinal fluid does not circulate properly around the brain, and collects in the head, putting pressure on the brain); infections of the central nervous system, such as meningitis and encephalitis; neurological conditions such as chromosome disorders; hypoglycemia, PVL, Traumatic Brain Injury (TBI). It is now widely accepted that “cortical blindness” is not an appropriate diagnostic term for children with early, acquired visual impairment due to non-ocular causes.

cvi, harry potter glasses,

Not even the Harry Potter specs can fix CVI!

10 Characteristics of CVI

• A preference for color, predominantly red and yellow, but can be any color. Children are drawn to rich, highly saturated colors. Color is a visual anchor for them.
Need for movement, especially rapid movements. May fixate on fans or other similar objects. Older children (in the classroom) may not be able to “not look” when visually distracted by a ceiling decoration, movement in hallway or outside classroom window. This includes shiny things, mylar and similar items that will draw their attention.
Visual latency, meaning the patient’s visual responses are slow and often delayed. They need wait time in order to respond. With proper interventions, the latent times can greatly improve.
Visual field preference—the patient sees better in one area, i.e. right peripheral.
Difficulty with visual complexity, meaning not seeing an object when other stimuli, such as sounds, are present. If an environment is sensory complex, they have to choose which sense they are going to attend to. This includes the ability the analyze faces, which are very visually complex. This means that the kids will often avoid looking into unfamiliar faces.
Light-gazing and non-purposeful gaze. Since they cannot sort and categorize what they are seeing, if they cannot find something meaningful (to them) to look at, the child will have a non-purposeful gaze.
Difficulty with distance viewing (often mistaken for nearsightedness). This is due to what could be a visually complex environment. In these instances, the child will use memory to override their vision skills, which then makes it appear as if they can see–because they will be able to navigate familiar environments based on memory.
Atypical visual reflexes, such as not blinking when you tap bridge of nose or visually threaten child with fingers (ie, act as if you are going to poke in eye, judge response.)
Difficulty with visual novelty, meaning the patient prefers looking at familiar objects. Often confused with a hyper-interest in something, since they will fixate and show preference for the familiar. Prefer objects that they already know, therefore the brain doesn’t have to “sort out” the information. They have to be taught from the perspective of building a visual schema to work from, as they have none. They have no previous visual experiences or knowledge to draw from, it has to be taught.
Absence of visually guided reach. “Look, look away, reach.”

My child has been diagnosed with CVI. Now what?

The next step is to find someone (specialist) that can do an assessment on your child for CVI range. This is a range scale that goes from 1-10 and has three separate phases, and will help determine strategies to help your child improve. Your child may need vision services and/or orientation & mobility services, try to find providers that are familiar with the latest information on CVI. Note: a CVI range assessment exam IS NOT the same as a Functional Visual Assessment (FVA).

Shared Behaviors DOES NOT mean Shared Diagnosis

Here are some behaviors that kids with CVI exhibit:

  • lack facial regard/eye contact
  • delayed play skills
  • delayed speech/language skills
  • perserveration on familiar objects
  • delayed social skills

Sound like anything else you know? When assessing your child, make sure you explore ALL the options, as many physicians are still unfamiliar with CVI.

From Boston Children’s Hospital-

Confusing diagnostic entities include:

  • delayed visual maturation
  • autism spectrum disorders
  • severe bilateral central scotomata (with eccentric fixation)
  • dyskinetic eye movement disorders
  • profound mental retardation

Other Myths

“The child’s vision will vary from day to day, hour to hour.” FALSE. The child’s visual abilities do not change, the environment may change.

And unlike many ocular (eye-based) problems, CVI patients can improve their vision. Improved vision feeds cognition and builds those neuropathways. This means actual learning and improvement in skills can take place, rather than just an improvement in coping skills.

Websites:

APH CVI website- information on assessments, strategies, interventions, and so on.

State of West Virginia Dept of Ed-Look for button on left that says “Cortical Visual Impairment”

CVI Resources-Dr. Roman’s site from West Penn Hospital

AFB-The American Foundation for the Blind’s statement on CVI. Once you’ve read that, you can just click their icon up top to return to the home page and browse around at their other resources and information.

Resource and scientific papers from National Deaf/Blind Association

Little Bear Sees-website for and by parents of a child with CVI

Wonderbaby-great resource site for children with visual impairments.

Books:

 

 

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