Charles Bonnet Syndrome in Low Vision Patients

Charles Bonnet Syndrome (CBS): Prevalence and Characteristics of Visual Hallucinations. Psychological Profile of the Visually Impaired Patient With CBS

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.

Inclusion Criteria:

• Best corrected visual acuity between 1/20 (1.0 LogMAR) and 3.2/10 (0.5 LogMAR) in cases of central vision impairment.
• Residual binocular visual field ≤ 60% in cases of peripheral vision impairment.
• Patients with age-related macular degeneration, Stargardt's disease, or glaucoma.
• Age between 40 and 70 years.
• Signed informed consent.

Exclusion Criteria:

• Age under 40 years.
• Clear cognitive impairments that reduce patient reliability.
• Psychiatric disorders.
• Refusal to sign informed consent to participate in the study.
• Mental State Examination (MMSE) score below 22.