Prevalence and clinical characteristics of Charles Bonnet syndrome in Madrid, Spain

Abstract

Purpose: Charles Bonnet syndrome (CBS) is a condition characterized by development of visual hallucinations in patients with no cognitive impairment and significant loss of vision mainly caused by age-related macular degeneration (AMD) or glaucoma. Methods: This was a study of prevalence and characteristics of CBS diagnosed at the Neuroophthalmic Unit within the Ophthalmology Department of Hospital Clínico San Carlos (HCSC), Madrid, Spain. Results: The CBS prevalence in patients from HCSC Madrid is 0.47%, rising to 15% in patients with low vision. Women over 80 years of age comprised 58.3% of the patients, who mainly had AMD (58.3%). Main characteristics of hallucinations included animals (50%), color (58.3%), moving (75%), 6- to 12-month evolution (50%), three times a day frequency (75%), and 3- to 5-minute duration (50%). Conclusions: Charles Bonnet syndrome is a complex process that must be treated jointly by ophthalmologists, neurologists, and psychiatrists in order to ensure accurate diagnosis and adequate management. New studies are needed in order to improve awareness of clinical manifestation of this condition, the incidence of which is underestimated due to patients' fear of being branded mentally ill, as well as physicians' lack of knowledge about CBS.