Visual hallucinations in patients undergoing intravitreal anti-VEGF agents in northern British Columbia: Prevalence and characteristics.
Abstract
Objective: Visual hallucinations (Charles Bonnet Syndrome) is a common phenomenon seen in patients with poor vision. The aim of this study was to determine the prevalence and characteristics of visual hallucinations in patients receiving intravitreal anti-VEGF (vascular endothelial growth factor) treatment in a northern community.
Study Design: Cross-sectional survey.
Methods: Participants with poor vision were recruited from an anti-VEGF injection clinic for treatment of age-related macular degeneration (AMD), diabetic retinopathy, and retinal vein occlusion. Anti-VEGF agents included bevacizumab, ranibizumab, and aflibercept. Patients were screened for visual hallucinations, and visual acuity and contrast sensitivity were tested.
Results: 122 patients (mean age 75.3 years) were screened in a period of 6 weeks. 49 were male (40.1%). Diagnoses included AMD (n=92; 75.4%), diabetic retinopathy (n=21; 17.2%), and retinal vein occlusion (n=17; 13.9%). The prevalence of Charles Bonnet syndrome was 6.6% (n=8). Hallucinations usually involved people, lasted only minutes, and were associated with dim lighting. Poor visual acuity (p=0.002) and contrast sensitivity (p=0.001) were associated with visual hallucinations.
Conclusion: Patients who see an ophthalmologist for treatment of eye diseases may experience visual hallucinations. Thus, healthcare professionals can benefit from greater awareness of Charles Bonnet syndrome, as not all visual hallucinations are caused by mental illness.