How is Charles Bonnet syndrome managed?

Management of Charles Bonnet Syndrome

The primary management of Charles Bonnet Syndrome consists of patient education and reassurance that the hallucinations are a common phenomenon in visually impaired people and not a sign of mental illness. 1

Understanding Charles Bonnet Syndrome (CBS)

Charles Bonnet Syndrome is characterized by four key findings:

• Recurrent, vivid visual hallucinations
• Patient insight that what is seen is not real
• No other neurological or medical diagnosis explaining the hallucinations
• Some degree of vision loss 2

The prevalence of CBS among patients with ophthalmologic disorders ranges from 15% to 60%, depending on the definition and population studied 2. It is commonly underdiagnosed, with many patients fearing to report their symptoms due to concerns about being labeled as mentally ill 3.

First-Line Management Approach

Education and Reassurance

• Explain to patients and their families that these phantom visions are common in visually impaired people
• Emphasize that CBS is not a psychiatric disorder or sign of cognitive decline
• Provide information that discussion about the nature of CBS often leads to significant relief and decreased anxiety 2, 1

Self-Management Techniques

1. Eye movements: Teaching patients to make specific eye movements when hallucinations occur
2. Lighting changes: Adjusting ambient lighting (increasing or decreasing brightness)
3. Distraction techniques: Engaging in other activities when hallucinations begin 2, 1, 4

These simple behavioral approaches have shown effectiveness in reducing hallucinations in case reports and limited evidence from case series 4.

Vision Rehabilitation and Environmental Modifications

• Optimize remaining vision through vision rehabilitation services
• Improve lighting conditions:
  • Use task lamps and carry pocket flashlights
  • Reduce glare with tinted eyeglasses (yellow, amber, or plum)
  • Use visors when appropriate 2
• Increase contrast in the environment:
  • Use black felt-tipped pens instead of ballpoint
  • Use contrasting colors for everyday items 2

Advanced Treatment Options

Non-Pharmacological Approaches

• Transcranial Direct-Current Stimulation (tDCS): A recent trial of 16 subjects with CBS reported reduced frequency of hallucinations with inhibitory tDCS 2, 1
• Support groups: Psychological therapies and support groups are beneficial for patients with vision loss and CBS, showing moderate effect on depression 1

Pharmacological Options

• Currently, there is no significant evidence supporting the efficacy of pharmacological treatments for CBS from large controlled trials 2, 1
• Case reports suggest potential benefit from:
  • Selective serotonin reuptake inhibitors (SSRIs) like venlafaxine have shown effectiveness in isolated cases 5
  • However, these should be considered only in cases where hallucinations cause significant distress and after non-pharmacological approaches have failed

Monitoring and Follow-up

• Regular follow-up to assess hallucination frequency and impact on quality of life
• Monitor for atypical features that may suggest diagnoses other than CBS:
  • Lack of insight into the unreal nature of images
  • Images that interact with the patient
  • Hallucinations in other sensory modalities
  • Progressive cognitive decline 2, 1
• Approximately 60% of patients experience improvement or resolution of hallucinations within 18 months 1

Special Considerations

• Be vigilant for comorbid depression or anxiety which may require separate treatment 2
• In rare cases, CBS may overlap with psychiatric disorders, complicating both diagnosis and management, especially when symptoms become more entrenched or resemble psychosis 6
• Patients with total vision loss may require more intensive monitoring and support 6

The evidence strongly supports that education, reassurance, and simple behavioral techniques should be the cornerstone of CBS management, with more advanced interventions reserved for cases where these approaches prove insufficient.