An observational study in Charles Bonnet Syndrome, sponsored by Fondazione Policlinico Universitario Agostino Gemelli IRCCS. Enrolling by invitation at 1 site in Italy. Open to participants aged 40 Years to 70 Years. Per ClinicalTrials.gov, last updated 2026-05-01.
Sponsored by Fondazione Policlinico Universitario Agostino Gemelli IRCCS · Observational
Among patients with chronic and degenerative ocular diseases that cause visual limitations, the presence of Charles Bonnet Syndrome (CBS) may be detected as a comorbidity. CBS is as a phenomenon of complex visual hallucinations occurring in individuals with reduced visual function, in the absence of cognitive alterations, psychiatric and/or neurological conditions. It is estimated that 15.8% of patients with age-related macular degeneration and 13.5% among glaucoma patients have CBS. Prevalence rates vary widely, and this may depend on inconsistent diagnostic criteria, variability in the questions used to determine if an individual has visual hallucinations, and the reluctance of people to admit to having strange visions for fear of being considered mentally ill. Visual hallucinations can be invasive and debilitating, compromising mental health, quality of life, and rehabilitation in visually impaired individuals. Patients may experience confusion, anxiety, anger, paranoia, and social isolation. Regarding psychological aspects, about a third of patients report experiencing distress and fear,higher anxiety and social dysfunction particularly during the initial onset of symptoms and in the terminal stage of the disease.Screening questionnaires will be used.
As part of our clinical practice, screening questionnaires will be used to assess the mental health and psychological profile of enrolled patients:
PHQ-9 (Patient Health Questionnaire): A 9-question tool for screening depression, with scores ranging from 0-27 to assess depression severity. Scores above 5 require referral to a clinical psychologist; scores 15+ suggest psychiatric evaluation.
GAD-7 (General Anxiety Disorder): A 7-item tool to screen for generalized anxiety disorder, with scores from 0-21. Scores 10+ require clinical psychologist referral, and 15+ indicate the need for psychiatric evaluation.
SCL-90R (Symptom Checklist-90): A 90-item questionnaire assessing a range of psychological symptoms, including depression, anxiety, and aggression, rated on a Likert scale from 0 to 4.
NEI VFQ25 (National Eye Institute Visual Function Questionnaire): A tool to assess the quality of life related to vision.
GSES (Generalized Self-Efficacy Scale):A 10-item scale to measure perceived self-efficacy and coping mechanisms for stressful life events, rated on a 4-point Likert scale.
PSS (Perceived Stress Scale):A tool to measure how individuals perceive their life as stressful, focusing on unpredictability, uncontrollability, and overwhelm.
GHQ-12 (General Health Questionnaire-12):A 12-item questionnaire to identify general mental health problems, focusing on the past two weeks.
Fondazione Policlinico Universitario Agostino Gemelli IRCCS is the lead sponsor of 920 studies on the registry; 529 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Visually impaired individuals with central and peripheral defects who access the center for visual rehabilitation.
Exclusion Criteria:
Prevalence of the Charles Bonnet Syndrome
Prevalence of Charles Bonnet Syndrome, calculated as the ratio between the number of visually impaired patients affected by CBS and the total number of patients attending the visual rehabilitation center, multiplied by 100 (%).
Time frame: From baseline through study completion, up to 24 months.
Change in Generalized Anxiety Disorder-7 (GAD-7). 7 items score.
Scale range: 0 to 21 Interpretation: higher scores indicate a worse outcome (greater severity of anxiety symptoms) Cut-off: greater than 5
Time frame: 3 hours
Change in Patient Health Questionnaire-9 (PHQ-9). 9 Items score
Scale range: 0 to 27 Interpretation: higher scores indicate a worse outcome (greater severity of depressive symptoms) Cut-off: greater than 5
Time frame: 3 hours
Change in Symptom Checklist-90 (SCL-90) . 90 items score
Scale range: 0 to 4 (mean score across items) Interpretation: higher scores indicate a worse outcome (greater psychological distress) Cut-off: greater than 1.5
Time frame: 3 hours
Change in Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25). 25 items score
Scale range: 0 to 100 Interpretation: higher scores indicate a better outcome (better visual function and quality of life) Cut-off: less than 60
Time frame: 3 hours
Change in General Self-Efficacy Scale (GSES) score.
Scale range: 10 to 40 Interpretation: higher scores indicate a better outcome (greater perceived self-efficacy) Cut-off: less than 30
Time frame: 3 hours
Change in Perceived Stress Scale (PSS) score.
Scale range: 0 to 40 Interpretation: higher scores indicate a worse outcome (greater perceived stress) Cut-off: less than 15
Time frame: 3 hours
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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Charles Bonnet Syndrome
Fondazione Policlinico Universitario Agostino Gemelli IRCCS