A group of clinicians in the United States with expertise in diagnosing cerebral/cortical visual impairment (CVI) convened in a workshop sponsored by the National Institutes of Health (NIH) and published a working definition of CVI in Ophthalmology, the journal of the American Academy of Ophthalmology.
Chang MY, Merabet LB; CVI Working Group. Special Commentary: Cerebral/Cortical Visual Impairment (CVI) Working Definition: A report from the National Institutes of Health CVI Workshop. Ophthalmology 2024;131:1359-1365.
https://www.aaojournal.org/article/S0161-6420(24)00565-7/fulltext
The definition encompasses 5 key elements:
1 Brain-based visual impairment.
Individuals with CVI have a neurologic disorder that affects the visual pathways in the developing brain, leading to problems with visual function and functional vision.
2 Not explainable by ocular abnormalities.
Though some individuals with CVI may have concomitant eye problems, the degree of visual dysfunction exceeds the severity of eye disease.
3 Heterogeneous manifestations.
CVI can affect “lower-order” visual function – aspects of vision that are typically measured in the eye clinic, such as visual acuity. However, CVI can also impact “higher-order” visual function, which involves more complex tasks such as recognizing faces and objects.
4 Overlap with neurodevelopmental disorders.
Individuals with CVI may have other neurodevelopmental conditions such as autism and dyslexia, but CVI is distinct from these other diagnoses.
5 Older individuals may have CVI.
CVI may be unrecognized or undiagnosed until later in life, and individuals with CVI at all ages require support appropriate to their stage of life.
Melinda Chang, MD, is a member of the PCVIS board and a Pediatric Neuro-ophthalmologist at Children’s Hospital Los Angeles. Dr. Chang’s research includes methods to assess visual function and functional vision in CVI and autism.
Special thanks to Dr. Chang for providing this synopsis of the paper.