1 in 5 with vision loss see vivid hallucinations, Canadian study says
A new study looks at the little known, centuries-old medical condition called Charles Bonnet Syndrome.
When doctors talk about vision loss, the focus is often on what patients don’t see. A new study, however, shows that one in five Canadians with vision loss are seeing some spectacularly bizarre things — little men holding umbrellas at the end of their bed, strange women in long dresses dusting their homes, colourful rain drops falling in sheets before their eyes.
These types of vivid hallucinations are not a sign of dementia, as many patients and doctors believe, but a marker for a little known, centuries-old medical condition called Charles Bonnet Syndrome (CBS), said Dr. Keith Gordon, vice-president of research at the Canadian National Institute for the Blind (CNIB) and author of the study published in the current issue of Canadian Journal of Ophthalmology.
“People are afraid to tell their family, friends and even doctors that they’re experiencing hallucinations for fear of it being misunderstood as mental illness,” Gordon said. “With these findings, we are now able to shed more light on CBS and help raise awareness within the medical community and the general public about how prevalent it actually is.”
Gordon’s work is the first major study of CBS due to vision loss across of the three most common eye diseases — age-related macular generation, diabetic retinopathy and glaucoma. Findings are based on information provided by 2,565 study respondents over 40 years of age.
While it is not yet known exactly what causes CBS, research suggests it is related to an attempt by the brain to fill in information that would normally be obtained from the eyes.
“My ultimate goal is to raise awareness so society doesn’t rule people out or, God forbid, put them in nursing homes because they think they’re crazy,” Gordon said.
Josée Rivest is a neuropsychologist who works with seniors at Baycrest hospital in Toronto. She’s seen firsthand how a lack of knowledge about CBS can lead patients and families down a frustrating road.
“By the time they come to me, they’ve been shuffled around in the system,” Rivest said, noting some patients received psychiatric medications to deal with the visions, a potentially useless and risky treatment.
Rivest said it’s critical that specialists and general practitioners alike “systemically ask” patients who are starting to lose vision whether they see things that other people don’t see.
CBS hallucinations tend to begin soon after a person’s vision deteriorates. It can affect people of any age. There are two main types of hallucinations: simple repeated patterns and complex images of people, objects or landscapes. It’s common for visions to occur once or twice daily. The images may last a few seconds or minutes. Symptoms generally decrease in frequency after a year to 18 months. In some cases, the hallucinations can linger five years or longer.
CBS patients, unlike those suffering from mental illness, are aware that what they’re seeing is not real. Also, the syndrome affects only vision so patients who have this condition would not be hearing voices as well.
While the upside of a CBS diagnosis is confirmation of sanity, the downside is there is no treatment.
Jack Hunter, a retired private investigator, has been living with his visions for the past six years. Blind in one eye and suffering from macular degeneration in the other, he was watching the local news recently when a rope ladder appeared to be coming up the side of the broadcaster’s nose.
His first vision was of a woman in profile with grey hair and Victorian-style dress mopping the floor of his Etobicoke apartment. He’s seen brightly coloured bushes pop up in the centre console of a friend’s car. He’s seen the fine print of broadsheet newspapers where the words appear written in a foreign text. It’s been years since he could read an actual newspaper.
Who was Charles Bonnet?
Charles Bonnet Syndrome is named after the Swiss naturalist who in 1760 documented the “visions” of a “sane, elderly man with vision loss.” It turned out later that the sane, elderly man was Bonnet’s grandfather, Charles Lullin, a retired magistrate whose eyesight had deteriorated after cataract surgery.
It wasn’t until the late 1930s that the term “Charles Bonner Syndrome” was coined by Geneva neurologist George De Morsier to describe visual hallucinations in the elderly who remain sane.
How to cope with Charles Bonnet syndrome
There is no single simple test to diagnose CBS. A medical professional will likely try to rule out other conditions that could be causing visual hallucinations, such as Parkinson’s disease or dementia.
The Royal National Institute of Blind People in the United Kingdom suggests that standing up or moving slightly can help to get rid of the hallucinations. Some people also find that looking directly at the image they are seeing causes it to fade. Sometimes moving your eyes or blinking rapidly can also help. The CNIB notes that many people experience hallucinations when they are sitting quietly. The institute advises patients to try turning on the TV or radio or moving locations. Adjusting the lighting in a room can also help diminish the vision.
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