TY - JOUR

T1 - Prevalence of Charles Bonnet syndrome in low vision

T2 - a systematic review and meta-analysis

AU - Subhi, Yousif

AU - Nielsen, Mads Assenholt

AU - Scott, Daniel Andrew Richard

AU - Holm, Lars Morten

AU - Singh, Amardeep

N1 - Publisher Copyright: © 2022 AME Publishing Company. All rights reserved.

PY - 2022

Y1 - 2022

N2 - Background: Charles Bonnet syndrome (CBS) is characterized by vivid lifelike visual hallucinations and is typically seen in individuals with visual impairment. In this systematic review, we summarize current knowledge on the prevalence of CBS in patients with low vision. Methods: We searched 11 literature databases on 21 April 2021 for studies on the prevalence of CBS in low vision populations. Our protocol was registered in the PROSPERO database (reg. No. CRD42021255021). Eligible studies were defined as those on a population of low vision patients wherein the prevalence of CBS was evaluated (without any further restriction on the method for diagnosis of CBS). No restriction was enforced on study design, but we expected observational cross-sectional studies due to the nature of our research question. Two authors independently extracted data and evaluated risk of bias of individual studies using the Agency for Healthcare Research and Quality checklist for cross-sectional studies. Studies underwent qualitative review in the text and quantitatively in a prevalence meta-analysis using the randomeffects model. Sensitivity analysis was made to evaluate the robustness of the summary estimate. Results: We identified 11 studies, which summarized data on 4,521 individuals with visual impairment. Diagnosis of CBS was based on screening questions or interviews, which in positive cases often was explored in more detail with follow-up questions or interviews. Most studies either had normal mental state as a participant eligibility criterion or as a part of the diagnosis of CBS. The pooled prevalence of CBS in low vision patients aged ≥40 years was 19.7% (95% CI: 13.8% to 26.4%). The sensitivity analysis showed certain robustness in the summary prevalence estimate wherein prevalence estimates ranged from 16.9% to 22.5%. Conclusions: CBS is a prevalent condition in patients with low vision at a rate of approximately one in five patients. Considering that an estimated 239 million individuals have moderate visual impairment or worse, we estimate a global number of patients with CBS at approximately 47.2 million.

AB - Background: Charles Bonnet syndrome (CBS) is characterized by vivid lifelike visual hallucinations and is typically seen in individuals with visual impairment. In this systematic review, we summarize current knowledge on the prevalence of CBS in patients with low vision. Methods: We searched 11 literature databases on 21 April 2021 for studies on the prevalence of CBS in low vision populations. Our protocol was registered in the PROSPERO database (reg. No. CRD42021255021). Eligible studies were defined as those on a population of low vision patients wherein the prevalence of CBS was evaluated (without any further restriction on the method for diagnosis of CBS). No restriction was enforced on study design, but we expected observational cross-sectional studies due to the nature of our research question. Two authors independently extracted data and evaluated risk of bias of individual studies using the Agency for Healthcare Research and Quality checklist for cross-sectional studies. Studies underwent qualitative review in the text and quantitatively in a prevalence meta-analysis using the randomeffects model. Sensitivity analysis was made to evaluate the robustness of the summary estimate. Results: We identified 11 studies, which summarized data on 4,521 individuals with visual impairment. Diagnosis of CBS was based on screening questions or interviews, which in positive cases often was explored in more detail with follow-up questions or interviews. Most studies either had normal mental state as a participant eligibility criterion or as a part of the diagnosis of CBS. The pooled prevalence of CBS in low vision patients aged ≥40 years was 19.7% (95% CI: 13.8% to 26.4%). The sensitivity analysis showed certain robustness in the summary prevalence estimate wherein prevalence estimates ranged from 16.9% to 22.5%. Conclusions: CBS is a prevalent condition in patients with low vision at a rate of approximately one in five patients. Considering that an estimated 239 million individuals have moderate visual impairment or worse, we estimate a global number of patients with CBS at approximately 47.2 million.

KW - Charles Bonnet syndrome (CBS)

KW - low vision

KW - visual hallucinations

U2 - 10.21037/aes-21-37

DO - 10.21037/aes-21-37

M3 - Review

AN - SCOPUS:85132448133

VL - 7

JO - Annals of Eye Science

JF - Annals of Eye Science

SN - 2520-4122

IS - 12

M1 - 6793

ER -