Charles Bonnet syndrome in patients with geographic atrophy secondary to age-related macular degeneration: a cross-sectional study

Background: Age-related macular degeneration (AMD) is a prevalent cause of irreversible vision loss among the elderly. The prevalence and detailed characteristics of Charles Bonnet syndrome (CBS) remain largely unexplored in patients with geographic atrophy (GA) secondary to AMD. Objectives: To investigate the prevalence and characteristics of CBS in patients with GA secondary to AMD. Design: Prospective cross-sectional study. Methods: A total of 149 patients with GA secondary to AMD were previously screened and examined for clinical studies. These patients were then prospective contacted by telephone for this study, and 120 patients responded and agreed to do an interview on symptoms of CBS. All with CBS were inquired about detailed characteristics of their hallucinations. Results: Patients with GA secondary to AMD were aged 82.1 ± 6.2 years and 62% were of female biological sex. The prevalence of CBS was 25 in 120 (20.8%). Thirteen (52%) of those with CBS were not previously informed of the disease. We found no difference between those with and without CBS in terms of age, biological sex, hearing difficulties, whether living alone or with others, co-morbidity of psychiatric or neurological diseases, or psychotropic use. Characteristics of the visual hallucinations were reported to occur at various frequencies from daily to less than monthly, occur during various times of the day, and almost always last minutes at most. Ten in 25 (40%) had not told anyone of having CBS. Conclusion: One in five with GA has CBS, which ranks GA as an eye disease with one of the highest reported prevalences of CBS. The condition presents with a significant variation across the patient group. A very large proportion of those with CBS were not informed of the disease and had never told anyone of their condition by their own initiative.