In my last blog, I explained that visual function assessment is important in children as certain visual dysfunctions are more common in children with CVI. Whilst visual dysfunctions should alert a practitioner to the possibility of CVI, a significant proportion of children with CVI have normal eye test results.
Therefore, if a child’s eye examination was normal and the parents have concerns about their child’s vision, it is possible that their visual difficulties are brain-related rather than eye-related. Careful medical history taking can help us to identify risk factors for CVI.
Pregnancy
A healthy pregnancy is a good start for every child. Infections, substance abuse during pregnancy and maternal health conditions can potentially affect the unborn child.
Birth
In recent years, the survival rate of extremely premature infants has increased and outcomes for infants with other causes of brain damage have improved. Whilst this is a positive development, these children can be vulnerable. And so are children with a low birth weight or oxygen deprivation. Their risk of developing CVI is increased due to damage of grey and white matter in early development. The extent and location of damage determines the severity and presentation of the visual dysfunction.
Early years
CVI can also develop in a child’s early years, for example in children with cerebral palsy, hypoxic ischaemic encephalopathy, hydrocephalus, epilepsy, traumatic brain injury, genetic and metabolic disorders and developmental delay. My next blog will focus more on developmental delay and behavioural diagnoses.
Brain scans
Not all children with CVI have an abnormal MRI scan. So, whilst an abnormal brain scan is a positive risk factor for CVI, a normal MRI scan does not exclude CVI as a diagnosis.
Screening for CVI
If you are interested in screening for CVI, with a view to identify which children might benefit from an in-depth CVI assessment, you can watch this short video:
I am very keen to collaborate with optical practices and offer Practice training for CVI screening. I developed materials for screening to make it as easy as possible to participate. Please contact me for more information:
