Charles Bonnet syndrome

Epidemiology

• 10-13% of patients with visual impairmment (< 20/60 bilateral acuity) experience visual hallucinations

Pathology

• retinal &/or cortical lesions impairing vision

Clinical manifestations

• visual hallucinations
  • may be simple (diamonds or rectangles)
  • more often complex (animals, children, entire scenes)
• insight intact (or partially intact)
  • patients are aware that the hallucinations are not real
  • nonetheless, the hallucinations appear real to the patient
• visual impairment (see epidemiology)
• lack of organic brain disease or psychiatric disorder

Complications

• a patient who loses insight may become very distressed by the hallucinations

Management

• supportive therapy
• education: hallucinations a sign of visual impairment not mental illness
• low dose antipsychotic may be helpful for patients who lose insight & become distressed

More general terms

• syndrome
• eye disease (ophthalmopathy)