Visual Impairment

As many as 75% of children with cerebral palsy have a visual problem. [Odding: 2006] Assessment of vision and interventions for visual impairment are an important component of care. Problems may include:

Strabismus
More than half of children with CP exhibit strabismus, a condition where the muscles that control eye movement are out of balance, causing the eyes to be misaligned. The misalignment of the eyes causes double vision, which the brain stops by turning off vision in one eye. In children, this change can be permanent if the double vision is not corrected in the early years.

Acuity loss
Acuity loss may be present by itself or with cortical visual impairment.

Field defects
Field defects, especially homonymous hemianopsia and variants, are seen in hemiplegic cerebral palsy.

Cortical vision impairment (CVI) (aka cerebral vision impairment)
CVI is a broad term for visual and perceptual vision impairments that are a result of dysfunction, anomaly, or injury to the posterior visual pathways. [Pehere: 2018] It is the most common cause of visual impairment in children in developed countries. [Ozturk: 2016] CVI needs to be carefully considered because it can further increase a child’s disability. With CVI, the structure of the globe is normal, and children with CVI will exhibit normal pupillary reactions to light and normal eye movements, yet do not respond to visual information. It is caused by hypoxia ischemia, developmental brain defects, and various insults to the brain, such as infection and trauma.

Children with developmental disabilities, including cerebral palsy, should be assessed yearly by a pediatric trained ophthalmologist for visual function, which addresses the structures of the eye and functional vision, which allows a determination of what the child can actually process visually. There is often substantial improvement over time. Children with CVI should receive vision therapy, usually from Early Intervention Vision Services, then, after 3 years of age, see List of Schools for the Blind.