From the Guidelines
Charles Bonnet syndrome is a condition where people with vision loss experience repeated, lifelike, and vivid visual hallucinations that they know are not real.
Key Characteristics
- Recurrent, vivid visual hallucinations are a hallmark of the condition, as noted in the vision rehabilitation preferred practice pattern® 1.
- Patients typically have insight that what is seen is not real, distinguishing Charles Bonnet syndrome from other conditions 1.
- The syndrome can occur in individuals with any level of vision impairment, and some degree of vision loss is a common underlying factor 1.
- It is essential to rule out other neurological or medical diagnoses that could explain the hallucinations before diagnosing Charles Bonnet syndrome 1.
Prevalence
More than 20% of people with vision loss may experience Charles Bonnet syndrome, highlighting its significance in the context of vision rehabilitation 1.
From the Research
Definition and Characteristics of Charles Bonnet Syndrome
- Charles Bonnet syndrome (CBS) is a condition characterized by complex visual hallucinations in individuals who are cognitively normal, though often elderly and visually impaired 2.
- Patients with CBS experience vivid, complex recurrent visual hallucinations, which are usually "Lilliputian hallucinations" with micropsia, where characters or objects appear distorted and smaller than normal 3.
- The hallucinations are typically well-defined, organized, and clear images over which the subject has little control, and are believed to represent release phenomena due to deafferentiation of the visual association areas of the cerebral cortex 3.
Epidemiology and Clinical Presentation
- The prevalence of CBS has been reported to be between 10% and 40%, with a recent Australian study finding a prevalence of 17.5% 3.
- A study of 350 patients with Age-Related Macular Degeneration (AMD) found an incidence of CBS in 13% of patients, with a higher incidence in patients with massive loss of vision in the peripheral visual field 3.
- A 45-case series study found that women over 80 years old constituted 68.88% of patients, and the most prevalent hallucinations were of people and faces, in color, and in movement 4.
Diagnosis and Management
- CBS is often misdiagnosed, and patients may require only assurance of the benign nature of the hallucinations, while others may benefit from nonpharmacological and pharmacological interventions 5.
- Pharmacists should be aware of CBS and its treatment options to properly assist physicians in the medication-selection process to alleviate distress experienced by patients with CBS 5.
- Increased awareness of signs and symptoms associated with CBS is required among practicing clinicians, particularly in optometric and ophthalmologic literature 6.