Three cases of Charles Bonnet Syndrome in patients with advanced glaucomatous visual field loss but preserved visual acuity

PURPOSE: To describe three cases of Charles Bonnet syndrome (CBS) in glaucoma patients with preserved visual acuity. METHODS: Three glaucoma patients who had taken part in a recent CBS study were interviewed about their hallucinations. The patients underwent macular optical coherence tomography (OCT) of both eyes. The visual function was evaluated with visual field measurement (Humphrey visual field analyser) and visual acuity testing (Snellen scale). RESULTS: All three patients had preserved visual acuity (≥0.5 in both eyes) and at least one eye with advanced visual field defect (Mean Deviation worse than −12.00 decibel). They all reported vivid visual hallucinations with insight into the unreal nature of the hallucinations. CONCLUSION: Charles Bonnet syndrome can occur in glaucoma despite preserved visual acuity. Awareness of this relation is desirable among clinicians, as it will improve communication with patients.