A group of experts, brought together by the National Institutes of Health (NIH), has determined five pivotal aspects of a brain-originating condition that is now recognized as a major cause of vision impairment in children in the US and other developed countries. This condition, known as cerebral (or cortical) visual impairment (CVI), is prevalent among at least 3% of elementary school children. The visual challenges associated with CVI, such as difficulties in recognizing objects, people, or complex moving scenes, were outlined in a report published in Ophthalmology.
“Many children with CVI go undiagnosed or misdiagnosed due to a lack of awareness, leading to years of unaddressed vision issues,” stated Lotfi B. Merabet, co-author and ophthalmology associate professor at Massachusetts Eye and Ear and Harvard Medical School.
“Identifying CVI-related indicators is crucial for raising awareness and enabling eye care professionals to refer children for assessments, ensuring they receive timely rehabilitation and support,” emphasized Melinda Y. Chang, M.D., a co-author and clinical ophthalmology assistant professor at the University of Southern California.
The identified elements of CVI include the following:
1. **Neurological Basis:** CVI involves a spectrum of visual impairments due to neurological abnormalities affecting the brain’s visual pathways, leading to some level of functional vision deficits, impacting daily activities.
2. **Disproportionate Visual Dysfunction:** Even with concurrent eye issues, those with CVI experience brain-centered visual processing impairments that surpass ocular problems.
3. **Visual Deficit Variability:** CVI-related impairments can be noticed as lower-order deficits, like reduced visual clarity or contrast sensitivity, and higher-order deficits, including challenges with facial recognition and spatial orientation.
4. **Distinguishing from Other Conditions:** Although CVI can be associated with other developmental disorders like cerebral palsy, it is distinct from language, learning, or social communication disorders but can be misdiagnosed as such.
5. **Often Overlooked:** CVI may go unseen until the affected individual can articulate their vision challenges. Screening is advised, especially for those with higher risks of neurological injuries, such as premature infants with certain brain findings.
Director of NIH’s National Eye Institute, Michael F. Chiang, pointed out that significant work remains to enhance diagnostic and rehabilitation practices for CVI, thereby prioritizing it in their strategic agenda.
To advance research, NEI is coordinating the development of a database to collect comprehensive CVI data, which will be available to researchers for a deeper understanding of CVI symptoms and defining optimal assessment and care practices.
The definition of CVI was consolidated during a workshop by NEI, in collaboration with the National Institute of Child Health and Human Development and the National Institute of Neurological Disorders and Stroke. In support, the American Academy of Pediatrics also released guidance for pediatricians on identifying CVI in children.
The NEI spearheads efforts to combat vision loss and enhance living standards through research, innovation, collaboration, and education, pushing forward basic and clinical programs to discover treatments and expand opportunities for those with vision impairments.