CORTICAL VISUAL

IMPAIRMENT

(CVI)Created by Region 4 students:W. Cordero, M. Moes, & S. Smith

What is Cortical Visual Impairment?

Cortical Visual Impairment (CVI) is a complex, brain based processing disorder. It is the most common cause of vision impairment in young children in the United States. Usually, an eye exam does not reveal any abnormalities, but the child does not see as he or she should.

When the eye sees the object and sends the message to the brain, it is not properly processed. The term CVI implies that damage to the visual cortex of the brain is the cause of the vision disorder. This vision impairment is usually linked back to a prior incident that involved the brain.

What can cause Cortical Visual Impairment?

Common causes of Cortical Visual Impairment are:

• Hypoxic ischemic injury – which means lack of oxygen that causes tissue death due to blood loss

• Head injury• Infections• Brain hemorrhage• And Brain anomalies

How does Cortical Visual Impairment impact vision?

It is important to note that this diagnosis means different things for different children.

Cortical Visual Impairment impacts vision in the following ways:

• Complexity• Novelty• Color preference• Visual field preference• Light gazing/non-purposeful gaze• Visual reflex differences• Visual latency• Distance viewing• Movement• And performance in a normal eye exam

How is visual function affected by this diagnosis?

Symptoms of visual function demonstrated include:

• Vision that appears to be variable: sometimes on, sometimes off: changing by the minute, or on a daily basis.

• Many children with this condition may be able to use their peripheral vision better than their central vision.

• About one third of children with this disorder are photophobic, while others are compulsive light gazers.

• Color vision is typically preserved in children with this condition.

• The vision of children with this disorder has been described much like looking through a piece of Swiss cheese.

• Poor depth perception may be exhibited, which influences a child’s ability to reach for a target.

• Vision may be better when either the visual target, or the child is moving.

How is this condition treated?

This condition is different for each child; it depends on the extent to and severity of the insults to the brain, the period of development when the injury occurred, the child’s previous experiences, medications the child may be taking, and the child’s motivation.

It is diagnosed when a child has no visual response yet has normal pupillary response, and a normal eye examination; and a medical history with neurological problems. The result of an MRI combined with how the child is functioning visually, are the basis for diagnosis.

Treatment of any underlying neurologic disease should be organized by the primary care physician. It is very important to start with early intervention to help stimulate visual development. There is a limited time frame for visual development and treatment at an early age is crucial in order to maximize improvement.

What teaching strategies can be used?

Children with CVI can benefit from the following type of stimulation:

• Large high contrast, lighted reflective and moving objects; mobiles.• Touch or sound to attract the child’s attention.• Visual materials presented in a simple, non-cluttered manner with

increasing complexity as can be tolerated.• A great deal of energy is needed to process information visually. The

child might tire easily when called upon to use his visual sense. Allow for

intermittent "break" times. • Positioning is important. Keep the child comfortable when vision use

is the goal to ensure that "seeing" is the primary task.• In some cases, head support should be provided during play or work sessions, to avoid involuntary shifting of the visual field.• Try many different positions to find the one in which the child feels

most secure. Infants and toddlers will demonstrate when and where they see best by their adaptive behaviors.

What teaching strategies can be used? continued…

• The simpler, more constant and more predictable the visual information, the better the child with CVI is likely to perceive and process it.

• Keep toys and environment simple and uncluttered. Use books with one clear picture on a contrasting simple background.

• Use familiar/real objects (bottle, bowl, plate, bath toy, diaper, cup, spoon, favorite toy) one at a time. Familiarity and simplicity aids perception.

• Use bright and bold colors that the child prefers since color perception is often intact.

• Looking at colored paper may help trigger visual responses.

References:

The Reference Shelf. (2007). Cortical Visual Impairment. Retrieved June 29, 2014 from http://www.sesa.orgCortical Visual Impairment Pediatric Visual Diagnosis Fact Sheet. (1998). See/Hear. Retrieved June 29, 2014 from https://www.tsbvi.eu/seehear/fall98/cortical.htmAmerican Association for Pediatric Ophthalmology and Strabismus. (n.d.) Cortical Visual Impairment. Retrieved June 29, 2014 from http:/www.aapos.org/terms/condition/40&q=cortical+visual+impairments&ei=bve3T_PC American Foundation for the Blind. (2014). Statement on Cortical Visual

Impairment. (2014). Retrieved June 29, 2014 from http://www.afb.org/info/living-with-vision-loss/eye- conditions/cortical-visual-impairmentAmerican Printing House for the Blind. (2012, August, 16). What is CVI?

Retrieved June 29,2014 from http://www.aph.org/cvi/define.htmlBlind Babies Foundation. (2011). Diagnoses and Strategies. Retrieved July 7, 2014 from http://http://blindbabies.org/learn/diagnoses-and-strategies/