Losing vision but not your mind

Joan Dearden from Bradford affected by macular degeneration and experiences Charles Bonnet Syndrome as a result.
Joan Dearden from Bradford affected by macular degeneration and experiences Charles Bonnet Syndrome as a result.
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Hallucinations can be upsetting. But, as Catherine Scott discovers, they do not have to be a sign of mental illness.

Faces and small creatures appearing in your vision sounds bizarre, even worrying, but it is something Joan Dearden has had to get used to.

Joan, 84, from Bradford is affected by macular degeneration and experiences Charles Bonnet Syndrome as a result. The phenomenon causes some people affected by sight loss to have visual hallucinations. It is not a sign of mental illness.

Research published last week in the British Journal of Ophthalmology shows that Charles Bonnet Syndrome affects people for longer periods of time and has more serious consequences than previously thought.

The research, conducted by King’s College London and the Macular Society, documented the experiences of 492 people who had experienced visual hallucinations as a result of sight loss and is the largest sample ever collected.

Despite being widely considered by the medical profession to have few adverse consequences and usually resolved within a few months, the research shows that 80 per cent of people asked had been experiencing hallucinations for five years or more and 32 per cent found the experience predominantly unpleasant, distressing and negative.

Joan has been experiencing Charles Bonnet Syndrome for more than 10 years.

“The first hallucination I had was when I went to catch a bus. It looked as if there was a man standing by the bus stop, but then he vanished. At first I was really puzzled as to where he went,” explains Joan.

“A couple of years later I started regularly seeing a face that appeared to be just out of reach. I have also seen little animals that look a bit like tortoises running along the carpet. I’m a retired science teacher, so when I was diagnosed with macular degeneration I did a lot of reading into the subject. This meant that I knew about the possibility of hallucinations. Some people are terrified when they experience them.

“I feel strongly that more people should know about Charles Bonnet Syndrome. There must be so many people who are experiencing it and are scared because they don’t realise what it is.”

The study helps characterise a group of people with what has been called “negative outcome Charles Bonnet Syndrome”. This group were more likely to have frequent, fear-inducing, longer duration hallucinations, which affected their daily activities and they were more likely to have their hallucinations attributed to serious mental illness.

Of those with Charles Bonnet Syndrome, 38 per cent regarded hallucinations as startling, terrifying or frightening when they first occurred and 46 per cent said hallucinations had an effect on their ability to complete daily tasks.

Worryingly, 36 per cent of people who discussed the issue with a medical professional said the professional was “unsure or did not know” about the diagnosis.

People with macular disease are particularly prone to Charles Bonnet hallucinations. They are thought to be a reaction of the brain to the loss of visual stimulation. More than half of people with severe sight loss experience them but many do not tell others for fear they will be thought to be mentally ill.

The Macular Society is trying to raise awareness of Charles Bonnet Syndrome so that people with sight loss know what to expect and why it is happening.

Dr Dominic Ffytche is a senior lecturer at King’s College London’s Institute of Psychiatry and led the research titled ‘Revisiting Charles Bonnet syndrome: factors influencing negative outcome.’

“Although there are, as yet, no specific treatments for Charles Bonnet Syndrome, the survey highlights the importance of raising awareness to reduce the distress it causes, particularly before symptoms start.

“All people with Charles Bonnet Syndrome are relieved or reassured to find out about it,” says Dr Ffytche

Tony Rucinski, chief executive, the Macular Society, said: “It is essential that people affected by sight loss are given information about Charles Bonnet Syndrome at diagnosis or as soon after as possible.

“Losing your sight is bad enough without the fear that you have something like dementia as well.”