Visual Hallucinations in Patients with Age-Related Macular Degeneration (AMD)

Abstract

Background: Charles Bonnet Syndrome is defined as visual hallucinations in psychologically normal people and has been associated with low vision for over two hundred years. Objectives: To evaluate the prevalence and complexity of visual hallucinations in patients with low vision. Design: A crosssectional comparative analysis of clinical visual data and hallucinatory phenomena in two groups of patients with age-related macular degeneration and a third control group. Methods: A questionnaire on visual hallucinations was administered to 145 patients and 58 control individuals. Measurements: Visual hallucination type (simple, complex) was examined and group comparisons were made using analysis of variance, cross-tabulations, and percentages. Results: Those individuals reporting visual hallucinations had a significantly lower mean visual acuity than comparative groups. Materialization and frequency of visual hallucinations were dependent on hallucination type. Hallucination type was not dependent on visual acuity. While visual hallucinations were reported by 40% of patients, Charles Bonnet Syndrome as defined in this study, was prevalent in 21% of the low vision cases. Conclusion: Charles Bonnet Syndrome occurs in approximately 1/5 of patients with age-related macular degeneration. Visual hallucinations are dependent on visual acuity rather than on age or ocular condition. Greater awareness of this condition among the medical and allied professions is important so that patients can be advised and reassured accordingly. Consideration should be given to including Charles Bonnet Syndrome as a discrete Syndrome in major classification systems.

Butterflies and black lacy patterns: the prevalence and characteristics of Charles Bonnet hallucinations in an Australian population

“…The prevalence of CBS has been reported to be anywhere from 10% to 40%, although two recent studies on Asian populations report the prevalence to be much lower, at less than 1% 26,27 . The high incidence of non‐reporting of the symptoms is linked to sufferers being reticent to discuss symptoms out of fear they will be labelled insane or emotionally disturbed 6,28,29 …”

The Charles Bonnet Syndrome in Patients With Neovascular Age-Related Macular Degeneration: Association With Proton Pump Inhibitors

“…This is slightly lower than previous studies in which the prevalence of visual hallucinations varied between 11 and 40%. 4,5,10,[13][14][15] Different definitions of CBS and different methodologies can justify the discrepancy; particularly, we included patients who, despite the diagnosis of neovascular AMD, still maintained good vision (34% had better eye BCVA 0.3 logMAR).…”

“…Patients were systematically asked a screening question based upon that used by Lannon et al 15 and translated to Portuguese: ''We are asking this question to every patient being examined here. Sometimes people with poor eyesight see things that they know are not actually there.…”

“…12 CBS has been associated with ocular pathology and visual loss, with the most commonly predisposing disorder being agerelated macular degeneration (AMD). 13 In fact, the prevalence of CBS has been reported to vary between 11% and 40% in patients with AMD 4,5,10,[13][14][15] and 0.4% to 3.5% in the general elderly population. 3,[16][17][18] Also, bilateral involvement and worse visual acuity have been associated with increased risk of visual hallucinations.…”

Clinical Characteristics of the Charles Bonnet Syndrome in Patients with Neovascular Age-Related Macular Degeneration: The Importance of Early Detection

“…Hallucinations in CBS can be classified as elementary, such as shapes, lights, or patterns; or complex – well-defined, recognizable forms such as faces, animals, and objects [5, 9, 10]. The clinical presentation is unpredictable: hallucination episodes can last from a few seconds to several hours, and images can be colored or in black and white, static or in motion, appear centrally or peripherally [11-16]. Also, triggers and suppressors of hallucinations vary widely among patients and reports.…”