Don’t overLOOK Cortical Visual Impairment – It is more common that you might think

In my work as an early intervention Physical Therapist I am often very focused on early mobility, the quality of a child’s movement, and if there are limitations to movement or weaknesses. This “tunnel vision” toward the gross motor arena serves a purpose, but I have learned that I must also look outside of my little motor box.  One thing that I have learned over the years is that VISION is so intricately related to how a child moves – and learns, yet VISION is often (ironically) overlooked.

Vision troubles often become evident in older children when they can’t see the blackboard (Or should I say Smart board?!) or are complaining of headaches or trouble with school work.  A trip to the Ophthalmologist or Optometrist is not often recommended in the early years, so it’s not a surprise that vision concerns in the young child often go unrecognized.

Have you ever heard of Cortical Visual Impairment (CVI)? If you haven’t and you work with children in any capacity, please read on.

WHAT IS CVI?

CVI is a temporary or permanent visual impairment caused by the disturbance of the posterior visual pathways and/or the occipital lobes of the brain. What does this mean? It means that the ocular (or eyes) may not have vision impairment (although there can be an co-existing ocular component), but that the brain’s ability to interpret and process what the eye is seeing is not functioning properly.  CVI is an impairment with vision that comes from the brain. In other words, the eyes may focus on an object but when that visual information is sent to the brain, it is not clearly recognized.  CVI can impact learning (as any vision impairment can) but is not associated with direct cognitive/learning challenges.

This illustration depicts this concept:

WHAT CAUSES CVI?

In simple terms, CVI is caused by any ischemic event – or any episode where the brain does not receive enough oxygen or blood.  This can happen during pregnancy and can be common with very premature babies (where blood vessels around the brain are very fragile), any disturbances with typical bran development, head injuries, or infections to the nervous system (such as meningitis).

This illustrates the area of the brain that interprets vision:

HOW IS CVI DIAGNOSED?

CVI is usually diagnosed using a combination of birth history, medical records (including brain MRI), and most importantly symptoms.  These children have normal reactions at their pupils, but appear to have trouble seeing. Children with CVI have specific symptoms when exploring and playing. Unlike true blindness, children with CVI may initially appear blind, but have the potential for their vision to improve as they are exposed to specific intervention.

WHAT ARE THE SYMPTOMS OF CVI?

• Initially appear blind (doesn’t respond by blinking or flinching when object is presented close to the face)
  
• Tend to see objects when held closer to the face
• May have preference to one side of one quadrant or vision (upper, lower, right vs left)
• Tends to look at an object and then look away (as a protective response because the visual appearance is “too much” for the brain to process all at once).  Will try to grab a toy without looking at it.
• Is able to see specific colors (red, yellow,orange), shiny objects, lights, and objects that move more effectively than other objects (vision may appear better if the child or the object is moving)
• Vision may change depending on time of day (fatigue is a factor as the brain is “working” to see) and even day of the week (depending on how a child is feeling)
• Has a harder time with looking at visually “cluttered” objects/environments (for this reason looking at a human face may be a challenge). Child may be better with simple and highly contrasted objects (black and white objects are more easily seen)
• May have a preference to use peripheral vision vs. central
• Depth perception may be affected
• May have delayed response to vision (called latency)
• May gaze non purposefully at lights

HOW IS CVI TREATED?

CVI is graded on a scale that ranges from Stage 1-2 (minimal visual response) to 9-10 (uses vision spontaneously for most activities). A CVI Specialist than perform a FUNCTIONAL VISUAL EXAMINATION/CVI EXAMINATION  to determine which stage the child is at and give specific recommendations to set up his or her environment and  promote visual improvement. How does this improvement occur? As the brain “works” to interpret what they eyes are seeing, new neurologic pathways are formed and strengthened.  This is why early intervention is important because the largest window for this to possibly happen if before 5 years of age. Recognizing the child has CVI, determining the stage, and pairing with specific goals is essential.  Goals of vision therapy  for a child with CVI often include helping the child to be as functional as possible with the vision he/she currently has while challenging the child slightly beyond their current abilities (so that positive change is made).

Some examples of adapting environments include adding a light box, using an iPad, or changing the location of what is presenting.

WHAT DO YOU NEED TO KNOW?

CVI is becoming more common with the more premature infants we are able to save at younger ages.  If you work with children, it is important to know the signs of CVI as you may be an early or initial source of recognizing that a child may have trouble processing visual information.  If you notice any of these characteristics in a child, speak to their parents about referral to an early intervention agency (a list of one for each state is located in the reference section of 1-2-3 Just Play With Me). Referral to a pediatric Opthalmologist or CVI specialist is essential so that a FUNCTIONAL VISUAL ASSESSMENT (how the child responds to the environment and not just the eye chart) can be performed. A vision specialist working with the child should be able to give recommendations for setting up a play space, classroom, or home environment, or for specific appropriate toys or learning tools. Keep in minding that these adaptations are ESSENTIAL for successful learning.

Here are some websites with tips and more information:

American Printing House For the Blind

Ability Path

Little Bear Sees 

Wonderbaby

Pinterest (this links to one of many wonderful sites for easy homemade adaptations for those with CVI

If you are a parent, caretaker, or an educator of a child with CVI, read Cortical Visual Impairment: An Approach to Assessment & Intervention by Christine Roman-Lanzy. It is THE go-to book on this topic.