CVI by the numbers
Understanding the leading cause of childhood blindness and low vision
For every diagnosed patient, we found four more likely cases of CVI
This is an epidemic and should be treated as such.
Creig Hoyt, MD, Professor of Ophthalmology at University of California, San Francisco
CVI (Cerebral / Cortical Visual Impairment) is a brain-based visual impairment caused by damage to the visual pathways or visual processing areas of the brain. And it’s currently the leading cause of blindness and low vision in children.
Using health insurance data and advanced analytics, the CVI Center at Perkins School for the Blind conducted an assessment focused on children and young adults with CVI in the U.S., drawing upon analysis from McKinsey & Company. This article explores the epidemiology of CVI and the pressing need for greater awareness, accurate diagnosis, and improved access to quality care.
Why does this matter?
CVI is common – but alarmingly underdiagnosed
Despite being the leading cause of childhood blindness and low vision, CVI isn’t widely recognized, diagnosed or understood – by educators, the medical community or even many vision professionals.
CVI poses significant risk to the future of our children
We estimate that there are over 180,000 kids with CVI in the US – and most of these kids are not being diagnosed.
Children with a missed diagnosis may not receive the supportive care they need to learn and find their own success. (And even those with a CVI diagnosis have difficulty finding specially trained educators.)
CVI represents opportunity: We can improve outcomes
With greater awareness, accurate diagnosis, and improved access to quality care and educational services, we can begin to improve outcomes.
We found that there are many regions with elevated rates of CVI and high social risk, so we must focus efforts in areas of greatest social need.
The following graphics in this story utilize scroll-driven animations. Turn animations off if you are motion sensitive or use a screen reader.
To better understand the impact of CVI in the United States, we leveraged nationally representative health insurance data and advanced analytics to identify patients with diagnosed CVI and likely CVI.
We identified 24,260 patients with diagnosed CVI…
… and using advanced analytics, we identified 155,980 additional patients with likely CVI.
This brings our total estimate to at least 180,449 patients with diagnosed or likely CVI in the US.
Based on our analyses, the estimated rate of diagnosis in the US is less than 20%.
Keyboard navigation is not available for this map. Please use the data table to explore county data.
The estimated prevalence of diagnosed CVI varies across the country. Most counties have less than 50 cases per 100k individuals aged 0-22, while others (predominantly in New Mexico, Texas, Kansas, and Oklahoma) exhibit a medium to high estimated prevalence, ranging from 100 to over 250 cases per 100k.
The estimated prevalence of likely CVI varies as well, ranging from less than 50 to over 250 cases per 100k. The counties with the highest overall estimated prevalence of CVI are primarily found in New Mexico, Texas, Oklahoma, Alaska, northern California, southern Oregon, and the New England region.
The Southeast and Mid-Atlantic regions tend to have medium to high CVI prevalence, while the majority of the Midwest and Mountain regions experience low to medium prevalence.
Our analyses likely represent a conservative estimate of actual CVI cases. One study found 1 in 30 primary school children may have CVI-related vision problems. Patients in our data experience multiple comorbidities and frequent healthcare encounters, consistent with published literature.
For example, 65% have a cerebral palsy diagnosis, 64% epilepsy, 72% developmental delay, 23% autism spectrum disorder, and 20% genetic anomalies. They experience an average of 14 specialty and seven primary care encounters. However, there is a wide spectrum of experience. Children with CVI and normal visual acuity, or lack of other comorbidities, and risk factors are less likely to appear in the data or be identified as having likely CVI.
In the following tab component, use the right and left arrow keys to move between tabs, then press the Tab key to move into the content.
Parents, teachers, and healthcare providers may overlook symptoms of CVI that do not resemble typical blindness. Even among CVI experts, there is a lack of standardization in the diagnosis, coding, and tracking of patients with CVI.
CVI expertise is lacking in certain parts of the US. Closer access to specialized CVI care is correlated with receiving a CVI diagnosis code. Children who do not have access to specialized care may go undiagnosed.
Below, we plotted the locations of health care providers who are experts in CVI diagnosis and care, as well as centers of CVI or ophthalmic excellence. Identified CVI care providers are mostly located in a diagonal band across the country starting in southern California and moving northeast across the country to Massachusetts; there is also a cluster of providers in southern Florida.
We measured the distance to the nearest CVI expert or care center for each patient and found that the distances vary widely, ranging from less than 1 mile in Massachusetts to over 400 miles in Georgia. Filtering down to counties with a higher estimated CVI prevalence, we found that most have a medium to high distance (129 to >250 miles) to a CVI care provider. Some of the high prevalence counties, however, are clustered near CVI providers.
Keyboard navigation is not available for this map. Please use the data table to explore county data.
CVI centers and specialized providers were identified by expert input and may not include all CVI centers or providers.
When a child has CVI, a team of different professionals and caregivers needs to work together. However, limited availability of resources and barriers to care access (e.g., lack of insurance) delay CVI diagnosis and intervention, and hinder a child’s ability to succeed and grow.
In some parts of the US, there is a paucity of healthcare support for kids with CVI. Lack of insurance may make it even harder for children to receive a diagnosis and support; policies determining eligibility and financial responsibility for CVI services vary across state lines and can be challenging for families to navigate.
Below, we identified areas with disproportionately fewer physicians per 100k people and high rates of uninsurance. In these areas, there might not be enough resources or pediatricians who know about CVI to help all the children who need it.
In counties with high estimated CVI prevalence, there is no clear pattern to the rate of physicians per 100k; however, most counties with higher estimated CVI prevalence tend to have medium to high rates of uninsurance. In Texas, Oklahoma, and the Southeast, most counties have both poor physician access and medium to high uninsurance.
Keyboard navigation is not available for this map. Please use the data table to explore county data.
Additional social risk factors may exacerbate the above obstacle, leading to further gaps in diagnosis, support, and achievement.
We identified areas of the US (e.g., the Southwest) where estimated CVI prevalence is higher and children may experience other social risk factors that have been shown to correlate with worse outcomes, such as poverty rate, percent of children on free or reduced lunch, and maternal mortality rate.
Counties with higher estimated rates of CVI tend to have medium to high poverty rates and most have medium or poor access to transportation. High CVI prevalence, high poverty rates, and poor access to transportation are concentrated in counties in New Mexico, Oklahoma, and across the Southeast.
Keyboard navigation is not available for this map. Please use the data table to explore county data.
Children with CVI and their families face significant challenges and a confusing healthcare landscape that is often inadequate to support their needs. Families, care providers, educators, and policymakers can take decisive action to ensure this group gets the services and support they need to fully access their world and define their success.
Educating parents, educators, and healthcare professionals about the unique visual behaviors and manifestations of CVI and appropriate referrals to providers familiar with diagnosing CVI can facilitate timely diagnosis and appropriate intervention.
Developing standardized and clinically validated diagnostic tools is essential to facilitate prompt diagnosis, especially for children with comorbidities (e.g., cerebral palsy, epilepsy).
Standardizing coding and measurement for CVI is crucial for accurate data tracking and understanding the unmet needs of this population. A dedicated and current CVI code in the International Classification of Diseases (ICD) system would enable better identification, monitoring, and evaluation of CVI through research.
Increasing availability of specialized support providers (e.g., Teachers of the Visually Impaired (TVIs), pediatricians, occupational therapists) is necessary to holistically meet the needs of children with CVI and ensure their success in society.
Improving access to resources designated for the blind and visually impaired could range from including CVI in eligibility criteria for state-based early intervention and special education services to expanding definitions for determining legal blindness to addressing community access and transportation barriers.
Successful CVI support programs should consider and help address a range of socioeconomic risk factors (e.g., rates of poverty, food insecurity, maternal mortality).
Directing resources to areas of greatest social need has the potential to achieve outsized impact by supporting children who are at the highest risk of being overlooked.
In summary, raising awareness, advocating for inclusive policies, and addressing socioeconomic risk factors are crucial steps in empowering children with CVI. By focusing on these steps, we can improve outcomes for a generation of children.
© 2023 Komodo Health, Inc. All rights reserved. Reproduction, distribution, transmission, or publication is prohibited. Reprinted with permission.
McKinsey Health Institute, McKinsey & Company. Vulnerable Populations Dashboard.
Use this map to explore how CVI prevalence and social risk factors overlap
1. Use the slider to filter counties by CVI prevalence:
2. Turn map layers on and off to explore how risk factors overlap:
Poverty rate: Percentage of population living below poverty level
Access to transportation: The Transportation Access Score measures access to public transportation and vehicle ownership rate.
The score is represented on a 0 to 10 scale, with higher scores indicating worse access to public and private transportation.