Filling in the Blind Spot: Integrating Charles Bonnet Syndrome Screening in Ophthalmology.

Abstract

Purpose: Charles Bonnet Syndrome (CBS) is an underdiagnosed condition affecting patients with significant vision loss who experience complex visual hallucinations while maintaining cognitive insight. This scoping review aims to synthesize existing literature on CBS prevalence, risk factors, and screening practices, and to propose a standardized, clinically implementable screening workflow for ophthalmologists.

Patients and methods: We conducted a structured literature search across four databases (PubMed, Embase, Web of Science, Scopus) using keywords related to CBS, visual impairment, screening, and diagnosis. Inclusion criteria encompassed peer-reviewed studies involving patients with vision loss that reported the use of screening tools, diagnostic criteria, or clinical assessments of CBS. Excluded were case reports with fewer than five patients, articles lacking full text or peer review, and those focused primarily on psychiatric or neurologic hallucinations. We identified 1,582 articles, with 89 studies meeting the final inclusion criteria.

Results: CBS prevalence ranged from 2% to 30%, depending on the underlying ocular condition and screening method used. Age-related macular degeneration showed the highest association. Few studies utilized validated screening tools though the QR-SCB and NEVHI instruments demonstrated clinical utility. Barriers to diagnosis included patient reluctance to report symptoms and clinician unfamiliarity. We developed a pragmatic clinical model incorporating risk stratification, direct questioning, validated tools, and functional assessment to improve detection in ophthalmology clinics.

Conclusion: CBS remains underdiagnosed despite its significant psychosocial burden. A structured screening approach may increase diagnostic accuracy and support timely intervention. The proposed model offers ophthalmologists a practical pathway to integrate CBS assessment into routine care.