Unfortunately, visual impairment is common in children with cerebral palsy. As many as 75 percent will develop some degree of visual impairment during their development. Because sight is such a key element to a child’s growth and development, diagnosis and treatment of vision issues at the earliest possible stage is critical in children with cerebral palsy. Parents need to familiarize themselves with the types of vision disorders common in children with CP as part of an effort to provide them with a full and functional life as they grow older.
Cerebral palsy can result in many different vision disorders, but the 4 most common are CVI (cortical visual impairment), acuity loss, field loss and amblyopia.
CVI is a dysfunction of the brain and not a direct problem with the eyes. It is the most common visual impairment among children with CP. It is known as “cortical visual impairment,” “cerebral visual impairment” or sometimes “cortical blindness” (despite the fact that not all people who suffer from CVI are totally blind). The list of potential causes of CVI-asphyxia, ischemia or hypoxia during the birth process; developmental brain defects, head injury, hydrocephalus, infant stroke, etc. mirrors the list of potential causes for cerebral palsy. Symptoms of CVI include: poor visual acuity, abnormal response to light, atypical eye movement, fatigue from visual tasks and difficulty picking out specific objects in a busy array.
Acuity loss is what it sound like: blurred vision. Common farsightedness and nearsightedness are examples of acuity loss and can usually be treated by corrective glasses or contact lenses.
Field loss is the umbrella term for a dysfunction in the eye’s field of vision. For instance, “Central loss” would refer to a visual impairment in the center of the field of vision. “Hemianopia” refers to visual impairment in one of the four corners of the field of vision. “Island of vision” is when all but one or two isolated spots are visually impaired “Scotomas” refers to the reversal symptoms of “Island of vision-when only one or two spots are visually impaired. “Peripheral loss” (aka “tunnel vision”) is the loss of visual fidelity on one or more sides.
“Amblyopia” (aka “lazy eye) occurs when a person has trouble determining depth of field and one eye will have noticeably poorer vision than the other.
Apart from the symptoms of CVI listed above, it is important for parents of children with cerebral palsy to be on the constant lookout for other eye and vision related problems. Poor focusing or tracking, constant eye rubbing, squinting, chronic redness or tearing could be indicators of the early stages of a vision disorder and should be checked out as soon as possible.
Most vision impairments in children with cerebral palsy are just as treatable as they are in children without and many can be managed with corrective lenses of some kind. For children diagnosed with CVI, the treatment can become more involved. Recent developments in “visual stimulation therapies” can help maximize your child’s visual skills and resources. If a child’s visual skills have not reached prescribed milestones within the first 10 years, it may become necessary to begin training the child in non-visual forms of communication, writing and reading, including Braille and text-to-speech software. You will need to work with your child’s optometrist to develop the appropriate treatment and education path to fit the child’s specific needs.