Medical Professionals
How do doctors diagnose CVI?
Typically, an ophthalmologist, neuro-ophthalmologist, neurologist, and in some cases, an optometrist, will diagnose CVI. Also known as Cerebral/Cortical Visual Impairment, CVI is a brain-based visual impairment that the National Institutes of Health (NIH) CVI Working Group describes as “a spectrum of visual impairments caused by an underlying brain abnormality that affects the development of visual processing pathways and is characterized by deficits in visual function and functional vision.” (Chang & Merabet, 2024).
Doctors can diagnose CVI if their patient meets the following criteria:
1 The child has a neurologic condition affecting the visual pathways in the developing brain.
2 There is a visual dysfunction that cannot be explained by an ocular abnormality.
3 The visual deficits involve visual acuity, contrast sensitivity, visual fields, and/or higher-order visual processing.
4 The visual dysfunction cannot be explained by autism, dyslexia, or another disorder of learning, language, or social communication.
The child should have a complete eye examination. While some children with CVI have a co-existing ocular condition, this condition does not fully explain their visual loss. Children may need to be followed over time or undergo a workup to exclude other causes of vision loss, such as inherited retinal disorders or delayed visual maturation. Early diagnosis during childhood is ideal, but a doctor may diagnose CVI in adulthood.
A boy wearing glasses sits in a wheelchair and gazes up toward the ceiling light. A doctor faces him with a flashlight in hand. Credit: Jodi Mora Igual
“...routine vision screening may not accurately identify the brain-based visual impairment in children with CVI. Moreover, children with CVI often have medical complexity with other neurocognitive impairments and serious medical conditions that can make the diagnosis of CVI more difficult.”
CVI Diagnosis: The ophthalmologist’s role
The ophthalmologist is an important member of the multidisciplinary team that cares for a child with CVI. According to Diagnosis and Care of Children With Cerebral/Cortical Visual Impairment: Clinical Report, “Children at risk for CVI because of history, behavioral characteristics of CVI noted on physical examination, or abnormalities on the [Visual System Assessment in Infants, Children, and Young Adults by Pediatricians] should be referred for pediatric ophthalmologic evaluation.” (Lehman et al., 2024).
During the history taking, it is important to solicit observations of visual performance from the family and other members of the child’s care team. A child’s performance in a limited examination time, in an unfamiliar place, when he may be tired and hungry, may not be representative of true function. It can also be difficult to assess vision in children with multiple disabilities, serious medical conditions, or neurocognitive impairments. It is often the occupational or physical therapist who first notes a visual field defect in a patient.
A full ophthalmologic examination, including cycloplegic refraction, should be performed to assess visual acuity, look for characteristics of CVI, and identify the presence of clinically significant ocular conditions. Visual performance can be maximized by treating any ocular comorbidities, including any significant refractive errors. Dynamic retinoscopy is a useful tool to evaluate for accommodative insufficiency.
What to look for during an exam to diagnose CVI
- Absent or clumsy visually guided motor response
- Preferentially responds to a flashing light toy or brightly colored object (usually yellow or red) with ocular following, smiling, or head/truncal movements
- The child responds more vigorously with visual stimulation approaching from one side of the visual field or the other
- Delayed response to visual stimuli
- Takes longer to fix and follow, or to re-fixate to target in peripheral vision
- Looking up or away while looking at an object
- Parent or vision teacher history that the child interacts visually in a more focused way with an uncluttered workspace and lower sensory complexity
- Parent history of child preferring to gaze at lights
- Parent history of child not responding to people or large objects from across the room
Diagnose CVI, document, and refer for vision services
The ophthalmologist must diagnose and document the CVI diagnosis, as well as reduced visual acuity, if present. Patients may qualify for services based on the level of visual impairment, especially if a patient has a chronic visual condition that will impair educational progress.
Further assistance for interventions or accommodations that may help a patient reach his or her full potential depends on the diagnosis made by the ophthalmologist. Certify the child as being “legally blind” or “visually impaired” due to a neurological disorder under ICD-10 H47.61 Cortical Blindness. While children and youth with CVI usually are not completely blind, this diagnostic code will qualify the child for state-funded services for children with visual impairment.
When appropriate, a referral for an evaluation for vision services from the appropriate agency should be made. Referrals for infants and children before their third birthday can be made through their early intervention program or the appropriate state agency, depending on the patient’s state of residence. For children age three and older, referrals go through the school district or the appropriate state agency. The designated service providers are typically a Teacher of Students with Visual Impairment (TVI) and a Certified Orientation and Mobility Specialist (COMS). Early diagnosis and referral to vision services “may allow a child with CVI to engage more fully in school, activities of daily living, vocational pursuits, and recreational activities.” (Lehman et al., 2024)
Sometimes the wait for a pediatric ophthalmology appointment is lengthy. When a pediatrician has concerns about a child’s visual function, he or she may request a vision services evaluation before formal diagnosis.
Individualized Family Service Plan (IFSP)
Children up to age 3 who have a disability may be eligible for early intervention services provided through an Individualized Family Service Plan, or IFSP, under Part C of the Individuals with Disabilities Education Act.
Individualized Education Plan (IEP)
Children with a disability that interferes with education who attend a school with federal funding may qualify for an individualized educational plan, or IEP, under the Individuals with Disabilities Education Act.