Vision rehabilitation and Charles Bonnet Syndrome.

Purpose: To evaluate the prevalence of visual hallucinations in Charles Bonnet Syndrome (CBS) among patients at a Low Vision Clinic. To determine whether Low Vision Rehabilitation (LVR) intervention results in a decrease of these visual hallucinations.

Methods: We surveyed 50 consecutive new patients in a low vision clinic to determine whether they had experienced visual hallucinations consistent with CBS. All patients were: questioned about the presence of visual hallucinations; given an educational handout that described CBS and reassured them of the benign nature of these hallucinations; and administered Folstein's Mini Mental Status Examination (MMSE). During their low vision examination, all patients received low vision aids to improve their visual function. At follow-up patients who had symptoms of CBS were administered a second survey to evaluate whether they had experienced any change in the frequency of their visual hallucinations.

Results: Of the 50 patients surveyed, 12 of 50 (24%) had visual hallucinations typical of CBS. 6 of these 12 patients (50%) had daily recurring hallucinations. At mean follow-up of 34.9 +/-30 days, a second survey was administered to 11 of the 12 patients diagnosed with CBS. One patient was lost to follow-up. Three of the 11 patients (27.3%) experienced a decrease in the frequency of their hallucinations by 43.33% +/-30.55%. Eight of 11 patients (72.7%) did not note a change in their symptoms.

Conclusions: It is important to include direct questions regarding visual hallucinations in the case history of a low vision examination. LVR may decrease the frequency of CBS hallucinations in some patients. Rehabilitation strategies should include low vision devices that allow for improved visual function and patient education to provide needed reassurance.