You’ve taken an important first step towards an accurate CVI diagnosis: You took your child for a comprehensive eye exam. But now you’re confused because it was completely normal — and your child continues to have visual difficulty.
Remember that a routine eye exam looks at the health of your child’s eyes, not at the health or function of the visual brain. Your doctor may determine that your child’s eyes are completely healthy, but you might know that your child isn’t using his or her vision the way they should.
The central question to ask the doctor: “Is this CVI?”
Diagnosing CVI can be a complex process, and, at this point, there are no clinical tests to “see” CVI, not in brain scanning or in the tests in the ophthalmology office. To be even more challenging some of the symptoms of CVI are similar to other conditions that are more well known. Lack of attention? It could be ADHD. Slowness to respond to visual cues? Maybe it’s autism or a cognitive issue? Many kids with CVI have multiple diagnoses, such as cerebral palsy, retinopathy of prematurity, Rett syndrome and others, making diagnosis even more nuanced.
We understand how confusing this is, but there’s also a lot of hope. CVI is the most common cause of pediatric visual impairment in the developed world. It’s an area of ongoing research and growing interest — and more is being discovered about diagnosing CVI all the time.
Ocular vs. Cortical Visual Impairment/Cerebral Visual Impairment
Ocular visual impairment refers to vision problems caused because one or more parts of the eye are not working properly. On the other hand, cortical visual impairment/cerebral visual impairment is a brain-based visual condition. It impacts the visual pathways (which bring information from the eye through the brain) and the visual processing centers (the places in the brain that help you locate, attend and understand what you see).
What Causes CVI?
Every child’s experience with CVI is unique, but all children with CVI experience brain dysfunction whether visible in brain scanning or not. There are many well-recognized causes of CVI, and more are being identified as CVI diagnosis evolves. According to Boston Children’s Hospital, causes of CVI can include:
- Hypoxic-ischemic encephalopathy, when a baby doesn’t receive enough oxygen and blood flow
- Periventricular leukomalacia, a brain injury that affects preterm infants that causes the death of brain tissue
- Traumatic brain injuries
- Neonatal hypoglycemia, a condition in which blood sugar is lower than normal
- Metabolic disorders
- Twin pregnancy
- Central nervous system developmental defects
Additional causes include genetic disorders, intraventricular hemorrhage and hemispherectomy surgery. For more information and resources on hemispherectomy surgery, visit The Brain Recovery Project.
How to Obtain An Accurate Diagnosis
It’s estimated that 80 to 90 percent of a child’s knowledge comes from visual information and from the ability to link that visual information to what is heard, felt, smelled or tasted. When this important visual sensory channel is impaired, children miss a significant amount of learning opportunities and miss those linking visual experiences to help understand what the other senses are experiencing. Without visual skills to look around when you hear a sound, a sound is a random sound without meaning. That’s why, if your child has a normal eye exam but continues to display vision problems, it’s critical to press for an accurate diagnosis. An accurate CVI diagnosis will help guide you and your child’s team to create the most effective educational programming to support functional vision skills.
A CVI diagnosis is typically made by a pediatric ophthalmologist, neurologist, neuro-ophthalmologist, optometrist, or clinical low vision specialist who understands the visual behavior of CVI seen in an office visit. The understanding of your child’s difficulties is greatly enhanced by your sharing of the child’s visual history, and descriptions of what your child’s visual skills are across the day, across various tasks and across different settings.
That medical professional should refer the child for a complete CVI functional assessment by a teacher of students with visual impairments (TVI). If the doctor does not recognize CVI, a functional vision report by a TVI can help the doctor understand how your child struggles to use their vision, and this collaboration leads to a diagnosis of CVI. This sets your child on the path to access learning. Early intervention and assessment can help address your child’s vision sooner and set them on the path to fruitful learning through visual access and through compensatory skills access.
No patient is untestable: A CVI Q&A with Dr. Barry Kran: A conversation with Dr. Kran on evaluating patients suspected of having CVI, diagnosing CVI, and his approach to working with children, no matter their complexities
CVI evaluation and assessment
Diagnosing CVI thoroughly comprises several factors:
Background: This includes a full medical history and birth history; developmental history; and educational history
Evaluations: These could include ophthalmological, neurological, genetic, speech and language, metabolic, neuropsychological exams, and functional vision evaluation by a teacher of students with visual impairments who share evaluation results with the medical professionals.
Observation: Kids with CVI display many characteristic behaviors referred to as “visual behaviors”. An evaluation for CVI will examine:
- Appearance of the Eyes
- Movement of the Eyes
- Visual Attention
- Access to People
- Response Interval
- Upper Limb Precision
- Lower Limb Precision
- Sensory Integration
- Visual Field Abilities
- Impact of Motion
- Impact of Spacing/Object Arrangement/Clutter
- Form Accessibility
- Impact of Color
- Impact of Light
- Visual Recognition
- Visual Curiosity
A medical assessment includes:
- A complete eye exam from an ophthalmologist including consultation with your child's neurologist
- Review of medical history (genetic, metabolic) and birth history and parent interview.
An educational (TVI) assessment includes:
- A review of ophthalmology and neurology reports. Collaboration with parents, classroom teacher, early intervention team, speech and language therapist, occupational therapist, psychologist.
- File review of all medical, school and early intervention documents and assessments
- Observation in multiple environments
- Direct assessment around the well-known brain-based areas impacted by CVI
The importance of transdisciplinary assessments
CVI affects many aspects of a child’s functioning, not just their vision. That’s why it’s essential to get non-visual assessments from specialists like neuropsychologists, speech-language pathologists, physical therapists, and occupational therapists, always in consultation with a TVI.
Often, children with CVI also have auditory processing issues or overlapping learning disabilities. These specialists will help you get a complete picture of your child’s learning profile, so you can obtain tailored and thorough interventions.
Next steps: How to advocate for your child
You know your child best. If you suspect that his or her vision is impaired, don’t be afraid to press for answers. Seek out a pediatric ophthalmologist or neuro-ophthalmologist who has experience diagnosing CVI.
Once a diagnosis is made, it’s helpful to:
- Advocate. Once you have a diagnosis, your doctor might recommend waiting a year to check on your child’s vision. Don’t wait. Your child is struggling to learn in a world that isn’t matched to his or her visual abilities. The functional vision assessment will determine what your child's visual abilities are and create learning environments and materials that are accessible today. That accessibility sets your child on the path to build visual attention and begin to recognize the world around them. That process can't be delayed.
- Get an EI referral. If your child is under three, ask to be referred for early intervention in your state immediately. Every state has an early intervention program, which includes developmental, occupational, physical, and speech therapy. It’s important to seek out vision specialists (TVIs) who are trained in visual impairments and specifically trained in understanding CVI; these specialists can make in-home visits to children to assess your child’s needs and provide customized learning and play programs. They will help the team understand how to assess and serve children with CVI in condition of their CVI.
- Learn. Understand the Individuals With Disabilities Education Act (IDEA). This law provides services for kids with special needs.
- Connect. Join communities of families who have children with CVI. The CVI community will help you develop advocacy skills, understand approaches to education, and learn about additional resources to support your child. Join our CVI Now Facebook Group for parents today!
- Ask for Research: When methods for children with CVI are suggested, ask for current research before adopting these strategies.