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.

Charles Bonnet Syndrome in Patients with Open-Angle Glaucoma: Prevalence and Correlation to Visual Field Loss.

PURPOSE: To determine the prevalence and characteristics of Charles Bonnet Syndrome (CBS) and its relation to visual field loss (VFL) in patients with open-angle glaucoma (OAG). DESIGN: Prospective, cross-sectional study. PARTICIPANTS: Adult patients (n = 337) with manifest OAG with verified VFL and without significant macular disease or extraocular conditions known to cause visual hallucinations. METHODS: Patients attending the glaucoma outpatient department of the Skåne University hospital, Malmö, Sweden, between April 1, 2018, and December 31, 2018, were consecutively evaluated for inclusion. Potentially eligible patients admitting to having complex visual hallucinations were interviewed to explore the characteristics of their hallucinatory experiences. Recent automated visual field examinations were available for all participants, and swept-source OCT was performed in participants with CBS to rule out previously undiagnosed macular pathology. The correlation between potential risk factors and CBS was evaluated with logistic regression analysis. MAIN OUTCOME MEASURE: Prevalence of CBS in patients with OAG. RESULTS: Charles Bonnet Syndrome was found in 7.1% (95% confidence interval [CI], 4.7-10.6) of patients with OAG. Participants with CBS were more likely to have at least 1 eye with a visual field index (VFI) of ≤30% compared with those without CBS (71% vs. 34.2%; P = 0.001). Although the best-corrected visual acuity (BCVA) in the worse eye was significantly lower in participants with CBS (decimal equivalent of Snellen BCVA: 0.25 vs. 0.6, P = 0.003), 33% of these participants had a BCVA of ≥0.5 in the worse eye. In multivariable analysis, CBS was correlated to the VFI of the better eye (odds ratio, 0.984; 95% CI, 0.969-0.998, P = 0.030) and the BCVA of the worse-seeing eye (odds ratio, 0.210; 95% CI, 0.046-0.952, P = 0.043). CONCLUSIONS: Charles Bonnet Syndrome was not a rare condition in patients with glaucoma. Patients with a combination of advanced VFL and low BCVA had the highest risk of CBS; however, 1 of 3 patients with CBS had a BCVA of ≥0.5 in both eyes. These findings emphasize the importance of being attentive to symptoms of CBS in patients with glaucomatous VFL even when visual acuity is preserved.

Charles Bonnet Syndrome Prevalence in a Younger Ophtalmology Outpatient Population.

BACKGROUND: In the literature, most of the studies on Charles Bonnet Syndrome (CBS) were performed on older populations. This study aims to determine the prevalence and epidemiology of CBS and the nature of the hallucinations of the younger group of patients from an ophthalmology outpatient clinic of a university hospital. SUBJECTS AND METHODS: Twenty-eight patients were randomly chosen from the outpatient ophthalmology clinic of a university hospital, and those who agreed to participate in the study were included. First, the patients were asked if they had ever seen visions that other people cannot when they were fully awake. The patients who were experiencing this symptom were given sociodemographic questionnaire and Psychiatry Institute Visual Hallucination Questionnaire, and asked to explain their hallucinations in detail. To exclude a psychiatric disorder, the participants were made a psychiatric interview as well. RESULTS: The study included 19 female (67.9%) and 9 male (32.1%) participants. Five patients (17.9%) were diagnosed with CBS. Average age of the patients diagnosed with CBS was 39.4 (min.31-max.48). Three of the 5 patients (60%) with CBS noted negative emotions (fear, wince and bewilderment) about their hallucinations. CONCLUSIONS: The prevalence of CBS (17.9%) we've found is compatible with the medical literature. CBS may also be accompanied by "relatively milder" ophthalmologic problems (myopia, astigmatism, etc.). The hallucinations which CBS patients experience could be quite distressing, and the individuals might have hard times to reveal their complaints because of the apprehension of stigmatization. To inquire this symptom during clinical examination may be the first step to help these individuals.

Prevalence of Charles Bonnet syndrome in patients with glaucoma: a systematic review with meta-analyses.

Glaucoma is a widespread sight-threatening condition often only recognized when very pronounced. It is initially characterized by peripheral visual field losses, while advanced stages also affect the central vision. Some of these patients may experience visual hallucinations, the Charles Bonnet syndrome (CBS). In this systematic review and meta-analysis, we provide an overview of the literature dealing with the prevalence of CBS in patients with glaucoma. We searched the databases PubMed/MEDLINE, Embase, Web of Science, the Cochrane Central and PsycInfo on 22 March 2020. Eight studies (n = 827 patients) were identified and included for a qualitative and quantitative analysis. No studies included a representative sample of patients with only glaucoma. In patients with glaucoma in different stages and with ocular comorbidities, prevalence of CBS was 2.8% (CI95%: 0.7-6.1%). Among patients with glaucoma where all had bilateral low visual acuity, prevalence of CBS was 13.5% (CI95%: 8.4-19.6%). In patients with glaucoma who visited vision rehabilitation clinics, presumably due to an extensive vision impairment, prevalence of CBS was 20.1% (CI95%: 16.8-23.6%). Risk factors of CBS besides low vision were high age, female gender, reduced contrast sensitivity and not living alone. Taken together, we find that CBS may not be rare in patients with advanced glaucoma with and without ocular comorbidities. However, limitations of the current literature should be highlighted and careful approach towards conclusions is important. More studies are needed to better understand the prevalence and risk factors among different populations of patients with glaucoma.

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

PURPOSE: We investigated the characteristics, prognosis, and clinical outcome of the Charles Bonnet syndrome (CBS) in patients with neovascular age-related macular degeneration (AMD). METHODS: Five hundred psychiatrically healthy patients with neovascular AMD were screened for CBS. The individuals that fulfilled the inclusion criteria were systematically interviewed using a structured questionnaire that covered the impact, prognosis, risk factors, phenomenology, symptoms, and knowledge about the syndrome. A control group of 45 patients was used for comparison. Demographic data, current medication, and ocular risk factors were collected in all patients. RESULTS: Forty-five patients with CBS were identified. The majority of patients reported images that consisted of colored (62%) animals (44%) or faces (42%) that lasted for seconds (53%). Most patients reported a self-limited disease with a median duration of symptoms between 9 and 11.5 months, with only 7% knowing about CBS at symptom onset. The degree of visual deficit did not predict the characteristics, complexity, frequency, duration, or impact of visual hallucinations. One-third of patients reported negative outcome, which was associated with shorter duration of CBS (p = 0.023), fear-inducing images (p < 0.001), and impact on daily activities (p = 0.015). CONCLUSION: The prevalence of CBS in neovascular AMD patients is high and clinically relevant. Patients with recent onset of visual hallucinations and describing fear-inducing images are at greater risk for negative outcome. Periodic screening may minimize the negative consequences of this disease.

Prevalence of Charles Bonnet syndrome in patients with age-related macular degeneration: systematic review and meta-analysis.

Age-related macular degeneration (AMD) is the most common cause of visual impairment in the developed world. A number of patients experience complex lifelike visual experiences-Charles Bonnet syndrome (CBS). In this systematic review, our aim was to provide an overview of the CBS literature in relation to AMD, to determine the prevalence of CBS in patients with AMD and to provide an overview of associated demographical and clinical aspects. We searched the literature databases PubMed/MEDLINE, EMBASE, Web of Science, the Cochrane Central, and PsycINFO on 22 March 2019 for studies evaluating the prevalence of CBS in patients with AMD. Two independent authors extracted the data and evaluated risk of bias. Studies were reviewed qualitatively in the text and quantitatively in a meta-analysis including subgroup analyses for differences between demographic and clinical factors. We identified 18 studies with data on >4303 patients with AMD. We found an overall prevalence of CBS of 15.8% (95% confidence interval: 11.0%-21.2%). When looking at consecutively recruited patients with neovascular AMD from the clinic, prevalence of CBS was 7.2% (95% confidence interval: 4.3%-10.6%). Among visitors to visual rehabilitation centres, prevalence of CBS was 31.6% (95% confidence interval: 21.7%-42.3%). Taken together, we find that CBS is rather common in patients with AMD.

The elephant in the room: understanding the pathogenesis of Charles Bonnet syndrome.

PURPOSE: Charles Bonnet syndrome (CBS) is a syndrome characterised by complex visual hallucinations in individuals who are cognitively normal, though often elderly and visually impaired. Although first described over 250 years ago, the condition remains poorly understood and difficult to treat. RECENT FINDINGS: Our understanding of CBS pathogenesis has advanced little since it was first described, and much of the recent literature consists of case studies strikingly similar to the first published account of CBS. However, imaging studies have provided some indication as to the cortical areas implicated in the genesis of complex visual hallucinations, and the existence of similar hallucinatory syndromes in other sensory modalities suggests a common underlying mechanism. SUMMARY: This review begins by describing what is currently known about CBS, focusing on epidemiology, clinical presentation and diagnosis. It then explores potential starting points for better understanding the pathogenesis of CBS, namely the existence of similar conditions in other sensory modalities and the reproduction of complex visual hallucinations in sensory deprivation scenarios. Finally, it discusses how CBS should be approached in clinical practice.

Screening for Charles Bonnet syndrome: Should the definition be reconsidered?

Purpose: Charles Bonnet syndrome (CBS) is a condition in which individuals with visual impairment (VI) and with no cognitive deficits experience visual hallucinations, typically with no other sensory hallucinations. Although few isolated case reports of CBS from India have been published, the prevalence for CBS in India is largely unknown. The primary aim of this study was to estimate CBS prevalence in patients with vision impairment visiting a tertiary eye care center. Methods: The study was conducted in two phases. In phase 1, patients with VI, age ≥40 years with presenting visual acuity worse than 20/63 were enrolled. In phase 2, patients with presenting visual acuity worse than 20/63 and/or with binocular visual field loss, age ≥18 years were recruited. A CBS survey was administered only to those who passed a screening test for cognition impairment. Results: A total of 218 patients were screened (phase 1 = 113 and phase 2 = 105). Two-hundred ten patients (mean age ± standard deviation = 49.2 ± 17.3 years, males = 139) were found eligible to complete the CBS survey. Fourteen patients were found to have visual hallucinations. In addition, three other patients had visual hallucinations with associated auditory input to the visual imagery. All patients had complete insight about their hallucinations. Conclusion: Depending on the inclusion criteria, we found the prevalence for CBS in patients with VI to vary between 6.7% to 8.1% (if including patients with auditory input). More investigation is needed to assess the associated role of other sensory inputs (e.g. auditory) with the visual imagery experienced in CBS.

Charles Bonnet syndrome: development and validation of a screening and multidimensional descriptive questionnaire.

OBJECTIVE: The purpose of this study was to develop a French Canadian questionnaire for the detection of Charles Bonnet syndrome that allows for (i) valid screening and (ii) the examination of different dimensions of the client's visual hallucinations in order to better assess the resulting needs. METHOD: Questionnaire development was guided by interviews with visually impaired individuals experiencing visual hallucinations, as well as supported by scientific literature and expert experience. A clinical study involving 76 individuals with low vision was conducted to determine the sensitivity and specificity of the instrument according to criterion validation. RESULTS: Of the 54 closed-ended questions, a subset of 11 revealed a sensitivity of 1.00 and a specificity of 0.77. Two additional questions showed high discriminating potential. Improvements to the wording and structure of some questions aiming at needs assessment were identified and applied. The improved version consists of 55 questions grouped in 8 dimensions: (1) Screening; (2) Characteristics of hallucinations; (3) Psychological impact; (4) Psychopathological origin; (5) Coping strategies; (6) Context of appearance of hallucinations; (7) Time-related matters; (8) Psychosocial support. The screening is operationalized through an algorithm applied to the set of 13 questions. CONCLUSION: The questionnaire will be a valuable aid in screening for Charles Bonnet syndrome among the low vision clientele. However, the screening will need to be supplemented by a focused low vision interdisciplinary assessment including a visual examination and a clinical interview with a psychologist.

[Complex visual hallucinations in the visually impaired, the Charles Bonnet syndrome]. / Charles Bonnets syndrom: synhallucinationer hos synskadade - Svagt seende patienter bör informeras om detta benigna tillstånd, som kan vålla oro.

Charles Bonnet syndrome (CBS) is characterised by recurrent, complex and vivid visual hallucinations in the absence of cognitive dysfunction. Individuals with CBS usually maintain insight into the unreal nature of their hallucinatory experiences. There is a strong association between CBS and acquired visual loss and the most commonly described ocular pathology is age-related macular degeneration. However, CBS has been described in the context of visual impairment due to pathologies anywhere along the visual pathway. It is widely agreed that CBS is an underreported diagnosis caused by patients' reluctance to admit their hallucinatory experience because of fear of being labelled mentally ill. CBS is a diagnosis of exclusion and careful assessment must be made to ensure that other etiologies causing the symptoms are ruled out. Knowledge of CBS is nonetheless important, as it constitutes a benign differential diagnosis to diseases presenting themselves with visual hallucinations. In many patients the hallucinations generate considerable anxiety aggravated by the lack of awareness of CBS. Thus, a major part of the treatment is careful information about the benign nature of the condition. Optimizing visual function also has beneficial effects on the hallucinations. This is conducted by optical means such as visual aids and the employment of different types of surgical procedures.

Hallucinatory experiences in visually impaired individuals: Charles Bonnet syndrome - implications for research and clinical practice.

BACKGROUND: Charles Bonnet syndrome (CBS) refers to visual hallucinations that occur in individuals with preserved cognitive functions associated with visual impairment. METHODS: This article reviews occurence of visual hallucinations in subjects with CBS by journals published in English in the Pubmed database in the period 1992-2018. Criteria for selection of appropriate papers were sufficient information and perspicuous view on pathogenesis, epidemiology, clinical presentation and treatment possibilities of CBS. RESULTS: Most commonly, visual hallucinations in patients with CBS are complex, repetitive and stereotyped. Such individuals have preserved insight that those percepts are not real, and there is an absence of secondary explanatory delusions and hallucinations within other modalities. Seeing as the aforementioned percepts do not share all the characteristics of hallucinations, it remains unresolved how they should be referred to. Terms as release hallucinations, one that is reflecting its underlying pathogenesis, or confabulatory hallucinatory experiences have been proposed. Moreover, CBS has also been referred to as phantom vision syndrome and may occur in any ophthalmological disease. It is not particularly connected with loss of function along any level of the visual pathway. Although this syndrome is mostly associated with age-related macular degeneration, glaucoma and cataract, it could be related to almost any other ophthalmological conditions. The incidence of CBS alongside with mostly other ocular pathology is rising as population is ageing. CONCLUSIONS: Nonetheless, CBS remains commonly underreported, under recognized and/or misrecognized. Albeit the treatment recommendations and guidelines are not yet fully established, it is important to raise awareness of this specific and distinct condition, which inevitably implicates many differential diagnostic deliberations.