A vision-impaired
person of sound mind experiences
phantom images (visions) in
their visual field.
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A vision-impaired
person of sound mind experiences
phantom images (visions) in
their visual field.
Despite awareness initiatives, Charles Bonnet syndrome continues to languish at the margins of medical interest. One of the consequences of this state of affairs is that outdated information and misconceptions thrive. One such misconception is that eye disease (or injury) is the sole cause of the syndrome. This covers well known eye conditions such as macular degeneration, cataracts and glaucoma.
What is less understood is that the syndrome can be triggered even when a person's eyes are (structurally) fine. CBS can occur when there is damage anywhere along the visual pathways: from the optic nerve to the visual region of the brain (back of the head). Common medical causes for such damage includes stroke, brain tumour or traumatic head injury.
A recently published case adds a further layer to how susceptible the visual pathways can be to a negative outcome. A 60 year old woman with very good vision (6/6 in one eye [20/20] and 6/9 in the other [20/30]) was found to have a tumour behind the top of the nose and at the base of the brain. The vast majority of this tumour was successfully removed. She was subsequently given radiation therapy to attack the small remnants of the tumour that remained.
All seemed to be going well after the first 10 months as evidenced by another good eye test result and no unwanted symptoms. However, just two months later (ie. 12 months since completing her radiation therapy), it was discovered that the woman had suffered significant damage to the optic nerves. It was around this time that the woman first began to encounter unusual visual experiences including seeing geometric patterns, lions with manes and women's faces.
(Image courtesy of Mariola Grobelska)
It was determined that the radiation therapy had led to the deterioration of the optic nerves and its effects were still being felt. Since then, her vision has continued to decline. Alongside her progressive sight loss, her CBS visions have increased.
This case highlights that any damage to the optic pathways (beyond the eye itself) can be sufficient to activate CBS.
REFERENCE: A case of vision loss from radiation-induced optic neuropathy resulting in Charles Bonnet syndrome (2023). Applied Radiation Oncology, Vol 12(2): 34-38.
Now that we've got your attention, let's talk about the uncomfortable topic and how it relates to Charles Bonnet syndrome (CBS).
The word 'hallucination' has come to be associated in society with something significantly wrong in the mind. When a person experiences a visual hallucination ('seeing things that are not really there'), there are grave fears for mental illness, delirium or dementia. In the field of psychiatry, hallucinations are seen as a primary indicator that something is not quite right and that perhaps the person has lost a sense of contact with reality.
Roman soldiers and chariot hovering mid-air in a vision-impaired person
When the term 'visual hallucination' is raised, it conjures up a fearful prognosis for oneself or a loved one. The reason is simple: people tend to only know hallucinations as signs of illicit drug use or - far more commonly - a defective mind. That is, something has gone awry in the brain.
So when a vision-impaired person begins to see things in their immediate environment that others cannot see, then it's quite understandable that they start to question their own experiences and what it means for them. For example, seeing orange elephants floating across the room every day before dusk is seen as just plain weird. It's also very concerning such that many arrive at the same thought: "First I lost my vision, am I now also losing my mind?"
With many types of clinical conditions, the person often believes - or has a strong suspicion - that what they see is genuinely real. This is known as a true hallucination. However for CBS, within the first couple of weeks of their visions, the vast majority have concluded that what they see - even if incredibly life-like - is not (or cannot be) real. This ability to quickly work out that what they 'see' is actually the eyes (or the brain) playing tricks on them, shows their thinking remains sharp and sound. This scenario, which is so often played out for someone living with CBS, sets them apart from those in the community experiencing true hallucinations.
True visual hallucinations require two features:
With CBS, point one is definitely present but typically point two is not. CBS is not associated with any form of mental illness, dementia or delirium. It is rather a most unusual side effect of the brain's response to vision loss.
Patrick Moore, a board member of the Charles Bonnet syndrome Foundation since its inception in 2012, regrettably passed away last month.
Patrick was born in Birmingham, UK. He lived and worked in Coventry for the early phase of his adult life in the automotive industry (Alvis Car Company, Triumph, Rolls Royce). He attributed the relocating of his family to Melbourne, Australia in the early 1980s as due to the advent of Thatcherism. Patrick continued to work in the automotive industry in Melbourne (Nissan Australia) and eventually assumed the role of Industrial Officer within the personnel department.
In 1991, Patrick discovered that he had a rare form of macular disease. He noticed over the coming months that he struggled to find useful information about his condition. Further, he came to discover that the same issue befell those diagnosed with the more common macular degeneration. Frustrated by the lack of quality information, Patrick founded the Macular Vision Loss Support Society of Australia (MVLSSA) in 1994. He was to be the president of the Society for the following 23 years. Before the age of the internet and smart phones, the MVLSSA successfully spread accurate and up-to-date information about macular disease. One of the primary goals of the MVLSSA was to channel all monies received into furthering research into the condition. Patrick and his team lived up to its lofty goal: over $750,000 was raised over two decades and cutting edge technology was subsequently purchased for the Eye and Ear hospital in Melbourne.
During his time as president, he was one of the first to openly speak about Charles Bonnet syndrome. He was aware that it was an internalised secret that many of his members did not discuss. Patrick had various guest speakers talk on the subject of CBS to its members. He was instrumental in bringing the condition out of the shadows where it had lurked for way too long. And this matter was also very personal for Patrick as he too lived with the syndrome. One of his recurring phantom images was of plants - possibly ivy - that seemed to quickly sprout from his TV and rapidly climb up the walls towards the ceiling.
Patrick came on board when the idea of the Charles Bonnet syndrome Foundation was first mooted. Over the past decade, Patrick was dedicated to the CBS cause. He met with parliamentarians and peak medical body representatives to try to instigate much needed change in the eye health care sector. He also was a huge advocate for raising CBS awareness in residential aged care services where he felt the syndrome was chronically overlooked.
Patrick was 83 and is survived by his son, daughter-in-law, Brig and two grandchildren, Chris and Shanae.
By Scot Muirden
Charles Bonnet would be dumbstruck if he were alive to today. To think that the condition he first described over 260 years ago continues to reside in the shadows of medical interest is baffling.
What's more astounding is that CBS' estimated prevalence rate within the vision-loss community has transitioned from ˜rare' to ˜fairly common'. Yet those seeking more information about the syndrome from their GP, eye specialist or emergency ward practitioner are often met with a blank look: Charles what?
(Image courtesy of Jean Wimmerlin)
So we have this bizarre situation whereby a remarkable number of people “ both the lay public as well as health care professionals “ are undertaking online searches for information. Various terms are fed into the search engine:
These types of searches are leading people to Charles Bonnet syndrome. It's very often the first time they've encountered this medical name. It's often the first time that a loved one's peculiar visual symptoms start to make some sort of sense. It's commonly the first time that slithers of clarity finally pierce the prolonged sense of confusion and unknowing.
{Image courtesy of Brett Jordan)
The left out letter I stands for ignored. The syndrome continues to fall through the cracks. Not just the cracks of the general population's awareness but, far more concerningly, within the medical and health care system.
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The Charles Bonnet Syndrome Foundation is dedicated to raising awareness of CBS, what signs to look out for and how to better manage this condition.
As a charitable organisation, we rely principally upon memberships and donations to continue our work.
Please help us to support more people affected by CBS.
