Benefit of psychiatric evaluation on anxiety in patients with Charles Bonnet syndrome

OBJECTIVE: Charles Bonnet syndrome (CBS) is defined as an occurrence of visual hallucinations (VHs) in the absence of any psychiatric/neurological disorder. Significantly reduced vision due to age-related macular degeneration (AMD), cataract or glaucoma is the most common cause for CBS. Aim of this randomized controlled study was to assess whether additional treatment by a psychiatrist is beneficial for patients with CBS. METHODS AND ANALYSIS: Patients with visual acuity of 0.5 LogMAR or worse in the better eye were screened. Instruments used were an interview asking about details of the VH, a mental test and a questionnaire on quality of life. Patients with CBS were randomised into two groups: in group 1, a patient-doctor consultation was performed by an ophthalmologist, and in group 2 a consultation and, if needed, additional medical assessment and treatment was given by a psychiatrist. RESULTS: 4900 patients were screened. 390 patients met the inclusion criteria and among these a CBS prevalence of 34 patients (8.7%) was found. The female-to-male ratio was 4:1 and the average age was 79.3 ± 9.7 years. Four different types of VH were observed: 41% humans (n=14), 32% geometrical shapes/patterns (n=11), 15% plants (n=5) and 12% animals (n=4). The change in quality of life in patients with CBS was not significantly different in both groups (p=0.727, ophthalmologist: n=18, psychiatrist: n=16). CONCLUSION: It is essential for medical staff involved with patients suffering from severe vision loss to be aware of CBS. This will help to better identify and interpret symptoms and could also lead to a more adequate treatment for affected patients. DISCUSSION: It is essential for medical staff involved with patients suffering from severe vision loss to be aware of CBS. This will help to better identify and interpret symptoms and could also lead to a more adequate treatment for affected patients.