Charles Bonnet Syndrome Management
What is Charles Bonnet Syndrome?
Charles Bonnet Syndrome (CBS) is a benign condition affecting 15-60% of visually impaired patients, characterized by vivid, complex visual hallucinations with preserved insight into their unreality, requiring primarily education and reassurance rather than medication. 1, 2
CBS is diagnosed by confirming four key features: recurrent vivid visual hallucinations, preserved insight that the visions are not real, absence of other neurological or medical explanations, and documented vision loss. 2
First-Line Management: Education is Therapeutic
The cornerstone of CBS management is patient and caregiver education about the benign nature of these hallucinations, which by itself provides significant relief and reduces anxiety. 1, 2
- Inform patients and families that CBS hallucinations do not represent psychosis, mental deterioration, or dementia—this reassurance alone is therapeutic. 1
- Explain that these visual experiences are a normal consequence of vision loss, affecting up to 60% of visually impaired individuals depending on the population. 2, 3
- Emphasize that the hallucinations are caused by the brain's visual system remaining active despite reduced visual input, not by psychiatric illness. 4, 3
Non-Pharmacological Interventions
Teach self-management techniques as safe, first-line strategies that may reduce hallucination frequency. 2
Specific techniques to recommend:
- Eye movements (rapid blinking or looking side to side) 2
- Changing lighting conditions (increasing or decreasing ambient light) 2
- Distraction techniques (engaging in conversation, listening to music, or tactile activities) 2
These interventions have limited evidence from case series but carry no risk and may provide benefit. 2
Vision Rehabilitation Referral
All CBS patients should be referred to vision rehabilitation services to optimize remaining vision and address psychological complications. 1, 2
Vision rehabilitation addresses:
- Maximizing remaining vision through lighting modifications, magnification devices, and contrast enhancement 1, 2
- Preventing social isolation and depression, which commonly accompany severe vision loss 1, 2
- Providing peer support groups where patients can discuss their experiences with others who understand 2
The American Academy of Ophthalmology provides moderate-quality evidence that psychological therapies and support groups benefit vision-related quality of life and depression in visually impaired patients. 2
When to Consider Pharmacological Treatment
Pharmacological treatment is NOT first-line and should be reserved only for patients with severe distress despite education and non-pharmacological measures. 2
Important Caveats:
- There is limited evidence of efficacy for any pharmacological agent in typical CBS. 2, 5
- Atypical antipsychotics (risperidone, olanzapine, quetiapine) have been used in individual cases with variable success. 2, 4
- One case report showed complete resolution with venlafaxine (an SNRI), suggesting serotonergic pathways may be involved. 6
- For CBS patients who also have dementia, donepezil may be considered as it addresses both cognitive function and hallucinations. 7
Do not prescribe antipsychotics reflexively—typical CBS patients maintain insight and the hallucinations are benign. 2, 8
Red Flags Requiring Alternative Diagnosis
If any of the following are present, CBS is NOT the diagnosis and comprehensive neurological evaluation is required: 2
- Lack of insight despite CBS education (patient believes hallucinations are real)
- Hallucinations that interact with the patient (speaking to them, touching them)
- Accompanying neurological signs (confusion, altered mental status, motor symptoms)
Consider brain MRI and evaluate for:
- Dementia with Lewy bodies 2, 8
- Parkinson's disease 8
- Primary psychiatric disorders 2
- Medication-induced hallucinations 2, 8
Screen for Depression and Medication Causes
At every follow-up visit, screen for depression and anxiety, as vision loss significantly increases risk of mental health deterioration. 2
- Recommend professional psychiatric assessment for patients reporting severe mood changes, interference with daily life, or suicidal ideation. 2
- Review the medication list for anticholinergics, steroids, or dopaminergic agents that may contribute to hallucinations. 2, 8
Common Pitfalls to Avoid
Do not dismiss the psychological impact of vision loss itself, which requires addressing through rehabilitation and support services. 2
Additional pitfalls:
- Do not overlook medication-induced causes such as anticholinergics, steroids, or dopaminergic agents 2, 8
- Do not use antipsychotics as first-line treatment when education and reassurance are sufficient 2, 5
- Do not fail to make the diagnosis—CBS is frequently unrecognized in clinical practice, with proper diagnosis made in only 1 of 16 patients who consulted a doctor in one study 3
Monitoring Strategy
Follow patients longitudinally to ensure hallucinations remain benign and insight is preserved. 8, 5
- Reassess periodically for emergence of delirium, cognitive decline, or loss of insight. 8
- Watch for development of additional neuropsychiatric symptoms suggesting progression of underlying neurodegenerative disease. 8
- Use validated assessment tools if needed, such as the North-East Visual Hallucination Interview (NEVHI). 8, 5