Fifty Alzheimer’s disease patients, 20% of whom experienced visual hallucinations, were studied to try a find a correlation for the hallucinations. The results showed that those who showed visual impairment were significantly found to have hallucinations; this occurred to a greater degree when the visual impairment was greater. This study suggests that glasses and/or cataract surgery may help Alzheimer’s patients with visual hallucinations.
OBJECTIVE: Studies suggest a link between visual acuity and visual hallucinations in dementia, but links with specific eye pathologies have not been evaluated.
METHOD: Fifty patients (20 with visual hallucinations, 30 without) with probable Alzheimer’s disease had an evaluation of psychotic symptoms. Visual acuity was measured before and after refractions, and ophthalmological examinations included standardized assessments for cataracts and macular degeneration.
RESULTS: Impaired visual acuity and the severity of cognitive impairments were significantly associated with visual hallucinations. No patients with normal acuity (6/5 or 6/6 on the Snellen chart) experienced these symptoms. Impaired acuity improved with refraction in 60% (N = 12) of the patients with visual hallucinations. Of specific eye pathologies, only cataracts were significantly associated with visual hallucinations. Descriptive follow-up information suggests that an optician’s assessment for glasses improves outcome.
CONCLUSIONS: Glasses and cataract surgery need evaluation as prophylactic or adjunctive treatments for visual hallucinations in patients with probable Alzheimer’s disease.
Am J Psychiatry 1999 Dec;156(12):1983-5.
Royal Victoria Infirmary, Newcastle, United Kingdom.
PMID: 10588415, UI: 20053636