What is Cerebral Visual Impairment?

Image: a picture of a human brain

September is CVI Awareness month, so here is a blog post discussing this common, but very under-diagnosed condition.

Cerebral Visual Impairment (CVI) is the most common cause of vision impairment among children in developed countries, yet the majority of people, including health professionals, have never heard of this condition. Understanding CVI is a complex and challenging endeavor. In this post, I will attempt to provide an overview of Cerebral Visual Impairment, including a definition, common risk factors, diagnosis, and its functional impact for affected individuals.

When we think about vision problems, we assume issues lie with a person’s eyes. However, the most common cause of vision problems among children in developed countries is Cerebral Visual Impairment (CVI), a condition which originates in the brain, CVI leads to a myriad of visual challenges. In this post we will take a closer look at CVI, exploring some of the complexities, and effects on individuals' lives.

What is CVI?

Cerebral Visual Impairment, previously known as cortical visual impairment, occurs due to damage or differences in the visual pathways and centers in the brain. This means that while the eyes themselves may be healthy, the brain struggles to interpret the information sent by them. It's like having a perfectly functional computer monitor (the eyes) connected to a malfunctioning computer (the brain).

Who is at risk?

Cerebral Visual Impairment is thought to affect 20-90% of children and adults with common neurodevelopmental conditions, including cerebral palsy, prematurity, and Down’s syndrome. People who have experienced brain damage, due, for example, to inflammation of the brain (meningitis), pressure on the brain (hydrocephalus), or blood/oxygen deprivation (hypoxic ischaemic encephalopathy) are also at risk of having CVI.

Diagnosing CVI

Diagnosis can be challenging, as it requires specialized assessments by professionals familiar with the condition. Functional vision assessment is usually undertaken, which involves observing how the person uses their vision, and other senses, to access their environment.

Manifestations of CVI

CVI presents a wide range of symptoms, which can vary greatly from person to person. Some common manifestations include:

1. Difficulty with Visual Acuity: Individuals may have trouble seeing objects clearly or distinguishing details.

2. Visual Field Defects: Often people have difficulty seeing things in certain parts of their visual field.

3. Visual Motor Integration: Some people experience challenges in coordinating vision with motor skills, leading to difficulties with activities like catching a ball or navigating obstacles.

4. Complex Visual Processing: CVI can cause difficulties in recognising faces and facial expressions, objects, letters, and shapes.

5. Variable Visual Functioning: For many with CVI, visual abilities may fluctuate depending on factors like fatigue, environment, or other sensory input.

Impact on Daily Life

The effects of CVI can significantly impact various aspects of daily life:

1. Education: Children with CVI may struggle in educational settings due to difficulties with reading, writing, or understanding visual materials.

2. Social Interaction: Challenges in recognizing faces or interpreting social cues can affect social relationships and interactions.

3. Independence: Adults with CVI may face hurdles in tasks like cooking, driving, or navigating unfamiliar environments independently.

4. Emotional Well-being: Coping with the challenges of CVI can take a toll on mental health, leading to feelings of frustration, isolation, or low self-esteem.

Strategies and Support

While there is no cure for CVI, various strategies and interventions can help. Here are some examples:

1. Environmental Modifications: Simplifying visual clutter, using high-contrast materials, and providing consistent routines can make the environment more accessible.

2. Visual Aids: Spectacles, magnifiers, or electronic devices with accessibility features can assist individuals in accessing detailed visual material.

3. Educational Support: For school-aged children, working with educators who understand CVI and implementing personalized learning strategies is very important.

4. Therapeutic Interventions: Occupational therapy, orientation and mobility instruction, and other interventions tailored to address specific visual challenges can be beneficial.

5. Community Resources: Connecting with support groups, advocacy organizations, or online communities can provide valuable information, encouragement, and solidarity.

Advocacy and Awareness

Raising awareness about CVI is crucial to ensure that individuals affected by the condition receive the support and understanding they need. This involves:

1. Educating Others: Spreading knowledge about CVI among educators, healthcare professionals, and the general public can foster greater understanding and empathy.

2. Advocating for Inclusion: Encouraging inclusive practices in education, employment, and community settings can help create environments that accommodate individuals with CVI.

3. Empowering Individuals: Supporting individuals with CVI to advocate for themselves, assert their rights, and access resources that help them to navigate the challenges they face.

Conclusion

Cerebral Visual Impairment is a complex and often misunderstood condition that affects individuals in profound ways. More work is needed to raise awareness of the condition, both within Australia, and globally, because knowing who is most at risk, and getting better at recognising the characteristics of CVI, so that people can obtain a diagnosis is the first step.