Date of Award

January 2022

Document Type


Degree Name

Medical Doctor (MD)



First Advisor

Sarwat Chaudhry



Purpose: Charles Bonnet Syndrome (CBS) refers to a phenomenon of visual hallucinations that occur in people with acquired vision loss in the absence of psychological conditions. Notably lacking from our understanding of CBS is the frequency, characteristics and predictors of symptoms. We described the prevalence and characteristics of CBS symptoms that participants of the Age-related Eye Disease Study 2 (AREDS2) experienced and examined its association with late age-related macular degeneration (AMD) and cataract surgery. The prevalence of AMD and the frequency of undergoing cataract surgery are expected to increase as the US population ages.

Design: Secondary analysis of data from a randomized clinical trial

Participants: Participants in AREDS2 (n = 3651/4203; 87%) who responded to the CBS questionnaire at the AREDS2 close-out (5-year) and follow-on (10-year) visits

Methods: AREDS2 was a multi-center, randomized clinical trial of vitamin supplementation in older adults with AMD. Participants received regular eye examinations and cognitive function testing. Fundus photographs were centrally graded. Certified interviewers evaluated participants for CBS symptoms, which are defined by visual hallucinations. We used multivariate logistic regression to model associations between late AMD, cataract surgery status, and CBS symptoms.

Main Outcome Measures: Proportion of AREDS2 participants reporting CBS symptoms; and independent associations (odds ratios) between age-related eye condition and treatments (late AMD and cataract surgery) and CBS symptoms.

Results: 446 (12%) participants reported having ever experienced CBS-related hallucinations, and were more likely to be older, using-acetaminophen, and have worse vision than those who did not report CBS symptoms. Having late AMD was associated with CBS symptoms at 5 years (OR, 2.08; 95% CI, 1.47 to 2.95) and 10 years (OR, 1.95; 95% CI, 1.46 to 2.60). Having had cataract surgery was also associated with reporting CBS symptoms at 5 years (OR, 1.35; 95% CI 1.01 to 1.82) and 10 years (OR, 1.42; 95% CI 1.14 to 1.77). The most common types of hallucinations were shapes, patterns, and faces.

Conclusions: CBS symptoms are common in older adults with late AMD or who had cataract surgery. Greater awareness of visual hallucinations by eyecare providers and increased efforts to diagnose CBS may help reassure patients and ameliorate anxiety.


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