The prevalence and clinical characteristics of Charles Bonnet Syndrome in Danish patients with neovascular age-related macular degeneration

Purpose: To investigate the prevalence and clinical characteristics of the Charles Bonnet Syndrome (CBS) in a group of Danish patients with neovascular age-related macular degeneration (AMD) and to study whether CBS is associated with a specific retinal morphology. Methods: Three-hundred consecutive patients with neovascular AMD attending assessment consultations following variable series of ranibizumab therapy were actively asked whether they had symptoms of CBS. If they responded positively, a detailed questionnaire was orally administered to inquire into the details of the symptoms. Detailed optical coherence tomography and autofluorescence was performed. A comparison was made between retinal morphology of a randomly selected equal number of patients without CBS to patients with CBS. Results: Twenty-five (8.3%) patients of 300 had hallucinations attributable to CBS. The median lesion size - measured as total area with increased autofluorescence - in the CBS group (median 14.2 mm²) was not significantly different from the non-CBS group (median 16.2 mm²); however, the patients with CBS had significantly larger areas of geographic atrophy (median 2 mm²) compared to patients without CBS (median 0.3 mm²) (p = 0.002). Conclusion: CBS is not uncommon in an unselected population with neovascular AMD, and symptoms of CBS may be associated with larger areas of geographic atrophy.