Cortical Visual Impairement
What is cortical visual impairment?
Cortical visual impairment (CVI) is bilateral decreased visual response due to an abnormality affecting the part of the brain responsible for vision.
What is delayed visual maturation (DVM)?
DVM is similar to CVI except the visual disorder/symptoms improve and resolve by age.
How does vision work in CVI?
The eye structure in CVI is usually normal. The eye takes a normal picture of the object and sends the message to the brain. The message is not properly processed or integrated because of the abnormal brain function. Many children with CVI have difficulty visually identifying an object and also filtering out peripheral visual stimuli to isolate the object.
What causes CVI?
Any process that damages the brain can cause CVI like stroke, decreased blood supply, decreased oxygenation, brain malformation or infection, hydrocephalus (increased pressure in the brain), seizure, metabolic disease, head trauma and other neurologic disorders.
What visual characteristics are associated with CVI?
Poor attention to visual stimuli, particularly complex visual stimuli
Delay in response to visual stimuli
Preference for looking at lights or viewing objects at close
Better vision when viewing moving objects than stationary objects
Does vision improve in CVI?
It is difficult initially to predict future visual function. Vision improvement may be seen in some children.
Can CVI be treated?
Treatment of the underlying cause is the key. Visual stimulation exercises are needed to improve visual function.
What type of stimulation is helpful for children with CVI?
Large, high contrast, lighted, reflective and moving objects
Touch or sound to attract child’s attention
Avoid visual tasks when child is hungry, tired, frustrated, etc.
Do children with CVI need an eye examination?
Yes. Some children with CVI have other associated visual disorders such as structural eye disease, misaligned eyes, or a significant refractive error. A Pediatric Ophthalmologist can evaluate the eyes to see if they are healthy, or if there is an abnormality in the eye that is contributing to the visual issues. Treating these associated conditions may include glasses or eye muscle surgery and can help maximize visual function.