From the Guidelines
Charles Bonnet syndrome is a condition characterized by recurrent, vivid visual hallucinations in individuals with some degree of vision loss, who have insight that what they see is not real and no other neurological or medical diagnosis to explain the hallucinations. This condition is experienced by patients with any level of vision impairment, as noted in the vision rehabilitation preferred practice pattern 1. The hallucinations typically involve seeing patterns, faces, people, or scenes that aren't actually present. According to the latest evidence from 2023 1, the syndrome is characterized by four key findings: recurrent, vivid visual hallucinations, insight that what is seen is not real, no other neurological or medical diagnosis to explain the hallucinations, and some degree of vision loss.
Key Characteristics and Management
- The syndrome occurs because when the brain receives less visual input due to eye diseases, it fills in the gaps with stored images.
- No specific medication directly treats Charles Bonnet syndrome, but reassurance that the condition is benign and not a sign of mental illness is crucial 1.
- Management strategies include improving lighting, staying socially engaged, and using eye movements or blinking when hallucinations occur.
- In severe cases affecting quality of life, medications like anticonvulsants, antidepressants, or antipsychotics at low doses may be tried, though evidence for their effectiveness is limited 1.
- Most patients find their hallucinations become less troublesome over time as they understand the condition better.
Prevalence and Awareness
- The syndrome affects approximately 10-40% of people with significant vision loss 1.
- Awareness of this condition helps prevent misdiagnosis as psychiatric disorders, highlighting the importance of recognizing Charles Bonnet syndrome in clinical practice 1.
From the Research
Definition and Characteristics of Charles Bonnet Syndrome
- Charles Bonnet Syndrome (CBS) is characterized by recurrent, complex, and vivid visual hallucinations in the absence of cognitive dysfunction 2, 3, 4, 5.
- Individuals with CBS usually maintain insight into the unreal nature of their hallucinatory experiences 2, 3, 4, 5.
- The condition is often associated with acquired visual loss, with age-related macular degeneration being the most commonly described ocular pathology 2, 3, 5.
Causes and Risk Factors
- CBS can occur in individuals with visual impairment due to pathologies anywhere along the visual pathway 2.
- The condition is not limited to older adults, as it can also affect children and young adults with sight loss, including those with progressive inherited retinal diseases such as Stargardt disease 6.
- Other risk factors include cataracts, glaucoma, and other ocular diseases that influence vision 3, 5.
Diagnosis and Treatment
- CBS is a diagnosis of exclusion, and careful assessment must be made to ensure that other etiologies causing the symptoms are ruled out 2.
- Treatment options include reassurance, nonpharmacological interventions, and pharmacological agents such as donepezil, which may be beneficial in patients with CBS and cognitive dysfunction 3, 4.
- Optimizing visual function through optical means, such as visual aids, and surgical procedures can also have beneficial effects on the hallucinations 2.