New voices: My grandmother, Mick Hucknall and me

'I saw that man from that band over there by the door, you know, the one with the red hair?''Do you mean Mick Hucknall?!''Yes, that's the one! He just appeared for a few seconds, smiled and winked at me and then he was gone!'

So began the first of many conversations with my grandmother about the bizarre 'visions' she had been experiencing over the last few years. One could be forgiven for assuming that such a comment made by a woman in her 90s was a sure sign of some mental health issues. But it turns out my grandmother, who has been diagnosed with the eye condition age-related macular degeneration (AMD), is in fact prone to experiencing 'Charles Bonnet syndrome' (CBS). This is a side-effect seen in around 10–15 per cent of people with severe visual loss, and it is unrelated to cognitive health (Menon et al., 2003).

CBS was first described in the 1700s when the Swiss philosopher Charles Bonnet heard of the experiences of his near-blind grandfather, who commented that he often 'saw' bizarre figures, animals and buildings that were not actually present in real life. Charles Bonnet went on to document several similar cases in psychologically healthy people who were experiencing partial or full blindness. Research into CBS has since progressed somewhat, though the exact causes are not yet fully understood.

Generally speaking, CBS is thought to be caused by visual deprivation which encourages the brain to 'fill in' missing information with visual images stored in memory (Burke, 2002). Whilst the likelihood of a visually impaired individual experiencing CBS is thought to be linked to some factors of their visual function (for instance, visual acuity of worse than 20/66 in the best eye has been shown to be a risk factor), evidence also suggests a connection with psychological factors such as social isolation, loneliness and shyness, in addition to other factors such as stress and fatigue (Menon et al., 2003).

Admittedly the appearance of the lead singer of Simply Red in one's living room is not amongst the most commonly reported hallucinations experienced by individuals with CBS. Many people with CBS report 'seeing' animals, landscapes or misty figures in old-fashioned dress. Whilst my grandmother has, over time, commented on all of these in some form, some of her visual experiences are perhaps less conventional; the 'leprechaun' prone to waving at her from her windowsill from time to time being a perfect example of this!

The occurrence of such experiences during quiet moments are of course surprising and frightening, but after a few moments of adjustment my grandmother was able to understand that they could not be real. It is this key property; full or partial insight into the unreal nature of the hallucinations, that helps distinguish CBS from the hallucinatory experiences occurring as a result of other mental health conditions such as schizophrenia. Other diagnostic criteria for CBS, although not officially defined, are that visual hallucinations must be formed, complex, persistent or repetitive, and be absent in other sensory modalities. In addition, there must not be any other primary or secondary delusions present (Gold & Rabins, 1989).

Despite their own realisation that the hallucinations are not real, many individuals with CBS do not actually present their symptoms to a clinician for fear of not being believed and subsequently being misdiagnosed with a mental health condition. These fears are perhaps not unfounded: in one study it was found that of 60 CBS patients, only 16 had spoken to their doctor about their hallucinations, and of these people, only one person was diagnosed correctly with CBS (Teunisse et al., 1996). The alarming account of an elderly woman with CBS who was incorrectly institutionalised (Hart, 1997) further serves to highlight a lack of knowledge and understanding of this condition from the sides both of those with eye disease and of many of those treating them. My grandmother herself revealed she had withheld her experiences from both doctors and family members for a considerable period – it was not until someone happened to point out an article relating to the syndrome that she realised she was not alone. It was this startling revelation that first ignited my interest in vision and in particular the importance of both considering and raising awareness of the experiences of the patient in relation to visual impairment.

CBS is, of course, not the only challenge faced by people with chronic eye disease. In addition to problems with glare and lighting, many people affected by vision impairment report considerable difficulties with a number of everyday activities such as reading, driving and mobility, which can cause a detrimental impact on their quality of life (QoL) and affect employment opportunities, self-esteem and independence. What is more, it is thought that many clinicians may underestimate the impact of vision loss on the patient's QoL (Brown et al., 2000). My grandmother herself, a long-time lover of reading, has struggled particularly with the rapid loss of her favourite hobby. By experiencing her difficulties firsthand, it was always fairly clear to me that visual loss cannot simply be characterised by labels, or numbers and outputs from clinical tests; it is vital to look to the experiences of the individual to truly understand the impact of visual impairment and how best to deal with it.

At the time when my grandmother's visual impairment had reached a relatively devastating level, I was coming towards the end of my undergraduate degree in psychology and, like many of my peers, was contemplating what next to do with my life. When I saw a vacancy for a studentship in the Department of Optometry and Visual Science at City University London, the job description immediately resonated. The PhD was to focus on the impact of glaucoma (another of the world's leading causes of irreversible blindness) on visual disability and quality of life. This would involve linking clinical measurements of visual function with what the patient could and could not do, in an attempt to shift the emphasis in disease management somewhat away from the eye, and more towards the person.

I am now in the final year of said PhD, and after a lengthy period of data collection involving glaucomatous and visually healthy participants, I'm analysing and collating a series of new findings. Some of this research has identified face-recognition difficulties as an additional challenge for patients with loss to central vision. Face recognition is in itself an important visual skill, where the presence and effects of a disability might not be truly appreciated (Yardley et al., 2008). In addition, a strong emphasis in our laboratory is on the eye-movement strategies of people with vision loss. Differences in eye movements have been observed in patients with glaucoma and may help explain some of the functional deficits shown by people with visual diseases (Crabb et al., 2010). A systematic review of the literature also revealed that, although research has increased in recent years, investigation into QoL in glaucoma represents only a tiny minority (around 1 per cent) of total research in glaucoma and may lag somewhatbehind that of many other chronic conditions (Glen et al, 2011). There is clearly still some way to go in understanding the impact of visual loss on the patient's life. Hopefully future research will ultimately move towards a more patient-centred emphasis in eye care, with a heightened awareness of the patient's specific experiences, disabilities and needs when considering their treatment. This should include raising awareness of CBS amongst healthcare professionals and the general public, to help resolve feelings of fear and loneliness that are often experienced by those affected.

Whilst I was completing my undergraduate degree, I was relatively unaware of the multidisciplinary opportunities available to those with an interest in psychology. I would advise any current students who are struggling to decide the direction of their career to 'think outside the box' and consider other disciplines in which their skills could be used. Despite branching out into a somewhat different field I have undoubtedly developed many skills across all aspects of the research process, from ethical applications, to participant recruitment and data collection, to data analysis and manuscript preparation. I have been fortunate to work within a talented and diverse group of people from a variety of backgrounds, ranging through psychology, optometry and ophthalmology, computing, statistics and mathematics, who have helped broaden my confidence and knowledge. And if it wasn't for my grandmother's fleeting romance with the lead singer of Simply Red, it is doubtful whether I would have ever headed in this direction!

Fiona Glen is a postgraduate student at City University, London
[email protected]

References

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