Autism or CVI?
This may seem a strange question at first: After all, most people are familiar with Autism, but not many people have heard of CVI, or cerebral vision impairment. However, a lot of behaviours observed in Autism are also observed in CVI. The difference is that CVI is a clinical diagnosis whereas Autism is a behavioural diagnosis or label. Both conditions can co-exist and for some children their autistic behaviours can at least be in part explained by their visual processing difficulties, or CVI. Understanding their visual processing difficulties is essential in order to manage the condition, and to receive appropriate support strategies and adaptations.
Let me share an example of a patient I met a few years ago. Peter (not his real name), aged 16, came to see me after he had already had an in-depth eye examination. His eyes were healthy and he did not require glasses. He had a diagnosis of Autism since early childhood. The reason he came was because his optometrist and his parents were concerned about his clumsiness and difficulties navigating through doorways and in crowded places. On further questioning and from direct observation combined with clinical investigations, we were able to identify specific visual difficulties which explained those behaviours as well as some of the reasons for his social withdrawal and difficulties connecting with other people:
Recognising faces
Peter was unable to recognise familiar faces by sight; instead, he recognised people by their voice, their hair and fashion style and other clues.
The term for this is prosopagnosia.
This is caused by malfunction of a specific area in the brain, the face recognition area
It is not hard to imagine that this has an impact on social communication
Understanding the meaning of facial expressions
Facial expressions were meaningless to Peter. It is particularly confusing when people say things that should not be taken literally.
Vision shutting down
Peter was able to see things around him when he was relaxed. However, as soon as there were stairs to negotiate, or floor boundaries, or a doorway, or when he entered a crowded or cluttered environment, his vision shut down and he was unable to see much at all. He had to cling onto the walls, the banisters, or his Mum.
School was stressful and tiring.
The term for this is simultanagnosia.
It is caused by dorsal stream dysfunction
I explained the visual difficulties and a couple of simple adaptations were implemented. For example, he was advised to arrive and leave for classes and move between classes at a different time from the other pupils, thereby making navigation through the school easier and less stressful and tiring. He tried this out and it made a huge difference. As a result he was able to attend more lessons before he had to go home exhausted. He also started using a cane to feel the ground ahead and he managed to go into town and walk in crowded streets without holding on to his Mum for the first time. He was given a list of strategies for recognising people and he felt better equipped to communicate his needs with others after the consultation. Whilst his Autism might still be there, his everyday function and quality of life was improved after assessment and management of his visual difficulties.
Every person with CVI experiences a unique set of visual difficulties and this leads to many different presentations. Why not read some of the publications about these topics to get a full flavour of how CVI can affect people in their everyday life and how this can be managed?
