Charles Bonnet syndrome in age-related macular degeneration - prevalence and clinical features in a Portuguese population / Síndrome de Charles Bonnet na degeneração macular relacionada à idade - prevalência e características clínicas numa população portuguesa

ABSTRACT Objective: Age-related macular degeneration (AMD) is the most prevalent cause of irreversible visual loss in the developed world. In late stages, it may lead to extremely low visual acuities, especially when associated with geographic atrophy or choroidal neovascularization. According to recent literature, Charles Bonnet syndrome (CBS) may be a rather common feature of late AMD. Methods: One hundred patients with late-stage age-related macular degeneration were actively asked whether they had symptoms of Charles Bonnet syndrome. Those that answered positively underwent a comprehensive questionnaire about the details of the visual hallucinations. Results: The following factors were significantly associated with Charles Bonnet syndrome: older age (+6.3 years; p=0.003), lower visual acuity in the better eye (Charles Bonnet Syndrome Group: 0.11; Non-Charles Bonnet Syndrome Group: 0.42; p=0.005) and female sex (Charles Bonnet Syndrome Group: 88%; Non-Charles Bonnet Syndrome Group: 43%; p=0.02). The visual hallucinations occurred mainly straight ahead (n=5), once per day (n=4), at no particular time (n=6), lasted some minutes (n=5), and disappeared after blinking (n=3) or looking away (n=3). The majority of patients lived alone (n=7), had not told anyone about the hallucinations (n=6), and associated the episodes with severe distress (n=5). Conclusion: Charles Bonnet syndrome was fairly prevalent in this late-stage age-related macular degeneration population. Our sample shows the importance of directly asking subjects about Charles Bonnet syndrome since they are often reluctant to admit to having visual hallucinations. Reassurance about its benignity is crucial to improve their quality of life.

RESUMO Objetivo: A doença macular ligada à idade (DMI) é a causa mais prevalente de perda visual irreversível nos países desenvolvidos. Em estadios avançados, esta doença pode levar a acuidades visuais extremamente baixas. De acordo com literatura recente, a Síndrome de Charles Bonnet (SCB) pode acontecer de forma relativamente comum na DMI tardia. Métodos: Cem doentes com degeneração macular da idade avançada foram interrogados ativamente sobre terem sintomas da síndrome de Charles Bonnet. Os que responderam de forma positiva foram submetidos a um questionário oral detalhado sobre os pormenores das alucinações visuais. Resultados: Os seguintes fatores foram significativamente associados à síndrome de Charles Bonnet: idade avançada (+6,3 anos; p=0,003), menor melhor acuidade visual corrigida no melhor olho (Grupo com Síndrome de Charles Bonnet: 0,11; Grupo sem Síndrome de Charles Bonnet: 0,42; p=0,005) e sexo feminino (Grupo com Síndrome de Charles Bonnet: 88%; Grupo sem Síndrome de Charles Bonnet: 43%; p=0,02). As alucinações visuais ocorriam principalmente em frente (n=5), uma vez por dia (n=4), em qualquer altura do dia (n=6), duravam alguns minutos (n=5) e desapareciam após pestanejo (n=3) ou desvio do olhar (n=3). A maioria dos doentes vivia sozinha (n=7), não tinha partilhado sua condição com ninguém (n=6) e associava os episódios a uma sensação angustiante (n=5). Conclusão: A síndrome de Charles Bonnet teve prevalência relativamente alta nessa população de degeneração macular da idade. Nossa amostra sublinha a importância de questionar diretamente sobre síndrome de Charles Bonnet, uma vez que os doentes se sentem muitas vezes relutantes em admitir alucinações visuais. A reafirmação da benignidade da situação é crucial para aumentar a qualidade de vida desses indivíduos.

Reversible Charles Bonnet syndrome secondary to upper lid ptosis.

Complex visual hallucinations can occur in visually impaired individuals with no underlying psychiatric disorder. This phenomenon is known as Charles Bonnet syndrome (CBS). It is more common in elderly patients who are suffering from impaired vision due to ocular or neurological disease processes, resulting in sensory deprivation. We report a case of CBS in an elderly female with marked ptosis, which was exacerbated following a knee replacement surgery under general anaesthesia. Her CBS symptoms persisted until surgical correction of the ptosis, with a rapid and dramatic resolution of her hallucinations. Although CBS is typically a chronic condition, unusually in this case it was acute and reversible.

Stimulus-Driven Cortical Hyperexcitability in Individuals with Charles Bonnet Hallucinations.

Throughout the lifespan, the cerebral cortex adapts its structure and function in response to changing sensory input [1, 2]. Whilst such changes are typically adaptive, they can be maladaptive when they follow damage to the peripheral nervous system, including phantom limb pain and tinnitus [3, 4]. An intriguing example occurs in individuals with acquired ocular pathologies-most commonly age-related macular degeneration (MD) [5]-who lose their foveal vision but retain intact acuity in the peripheral visual field. Up to 40% of ocular pathology patients develop long-term hallucinations involving flashes of light, shapes, or geometric patterns and/or complex hallucinations, including faces, animals, or entire scenes, a condition known as Charles Bonnet Syndrome (CBS) [6, 7, 8]. Though CBS was first described over 250 years ago [9, 10], the neural basis for the hallucinations remains unclear, with no satisfactory explanation as to why some individuals develop hallucinations, while many do not. An influential but untested hypothesis for the visual hallucinations in CBS is that retinal deafferentation causes hyperexcitability in early visual cortex. To assess this, we investigated electrophysiological responses to peripheral visual field stimulation in MD patients with and without hallucinations and in matched controls without ocular pathology. Participants performed a concurrent attention task within intact portions of their peripheral visual field, while ignoring flickering checkerboards that drove periodic electrophysiological responses. CBS individuals showed strikingly elevated visual cortical responses to peripheral field stimulation compared with patients without hallucinations and controls, providing direct support for the hypothesis of visual cortical hyperexcitability in CBS.

Reversible Charles Bonnet Syndrome After Oculoplastic Procedures.

Individuals with Charles Bonnet syndrome (CBS) typically have severe visual loss and experience visual hallucinations yet have no psychiatric disease. Visual impairment often is due to end-stage glaucoma or macular degeneration. We report 3 cases of CBS in patients who underwent an oculoplastic surgical procedure. One patient experienced binocular visual distortion due to excessive topical ophthalmic ointment, and 2 patients experienced monocular visual impairment from patching. Visual hallucinations resolved once vision returned to baseline. We highlight the possibility of transient CBS in postoperative patients who have temporary iatrogenic vision impairment in one or both eyes.

Keep an eye out: A rare case of acute-onset Charles Bonnet Syndrome after Stanford type A aortic dissection repair surgery.

Charles Bonnet Syndrome describes the triad of complex visual hallucinations secondary to ophthalmic pathology in psychologically normal people. We present a rare case of acute-onset Charles Bonnet Syndrome following cardiac surgery that resulted in profound loss of visual acuity in both eyes with characteristic visual hallucinations that were initially mistaken for delirium. Computed tomography of the brain revealed bilateral occipital infarcts, providing the substrate for Charles Bonnet Syndrome. A high index of suspicion should be maintained in cognitively intact patients with visual loss who are also experiencing visual hallucinations to ensure prompt diagnosis and management of this often overlooked condition.

Charles Bonnet syndrome secondary to exudative age-related macular degeneration - a case report.

Charles Bonnet syndrome is a condition manifesting as visual hallucinations associated with vision impairment in patients without the underlying n euro psychiatric pathologies. As the incidence of age-related macular degeneration is on the rise, we can anticipate increasingly frequent cases of Charles Bonnet syndrome in our patients. The aim of the paper is to present a case of a 75-year-old patient who developed visual hallucinations secondarily to severe bilateral vision impairment due to exudative age-related macular degeneration. Patients with advanced age-related macular degeneration and no history of neuropsychiatric disorders may present with visual hallucinations.

Charles Bonnet syndrome.

Introduction: Charles Bonnet syndrome (CBS) is a condition that causes visual hallucinations in patients without any mental illnesses. CBS is characterized by the presence of vivid, complex and recurrent visual hallucinations, and do not occur in the setting or as part of delirium or other psychological illnesses. The condition is present in patients who have visual loss due to age-related macular degeneration (AMD), cataracts and/or other ocular diseases that influence vision. Case report: A 81-year-od woman reported to ophthalmologist complaining of visual hallucinations that consisted of white pigeons. Hallucinations were present for two years and she was well aware that hallucinations were unreal. Mental illnesses were excluded by the psychiatrist. Complete ophthalmologic examination was performed, and finding revealed visual acuity of 0.3 (right eye) and 0.5 (left eye), in both eyes cataracts and AMD (wet form). Optical coherence tomography confirmed the fundoscopic finding of AMD. The patient rejected treatment of cataracts and AMD due to old age, and hallucinations persisted. Conclusion: CBS should be considered in patients with visual hallucinations and ocular diseases that influence vision. It is essential to distinguish CBS from mental illnesses, since patients with CBS are fully aware that hallucinations are not real. Awareness of CBS could help physicians upon referring patients to ophthalmologists instead of psychiatrists, and therefore avoid patients being misdiagnosed.