Response of the pupil to tropicamide is not a reliable test for Alzheimer disease
J. S. FitzSimon, S. C. Waring, E. Kokmen, J. W. McLaren and R. F. Brubaker
Department of Ophthalmology, Mayo Clinic, Rochester, Minn., USA.
OBJECTIVE: To confirm the putative hypersensitivity of the pupil to a weak
mydriatic in persons with Alzheimer dementia. DESIGN: Twenty patients with
Alzheimer dementia and 20 control subjects were examined. Automated
binocular infrared pupillography was performed in the dark after
instillation of 0.01% tropicamide or placebo. Ocular penetration of eye
drops was assessed simultaneously using 2% fluorescein sodium as a tracer.
SETTING: Rochester, Minn. SUBJECTS: Twenty patients and 20 cognitively
normal control subjects from the Alzheimer's Disease Patient Registry of
the Mayo Clinic, Rochester, Minn. MAIN OUTCOME MEASURE: Percent change in
the diameter of the pupil following topical ocular instillation of a
diluted concentration of the mydriatic drug tropicamide and penetration of
topically applied fluorescein into the aqueous humor. RESULTS: No
statistically significant difference was found between patients with
Alzheimer disease and control subjects in either the mydriatic response of
the pupil or in the rate of penetration of topically applied fluorescein.
CONCLUSION: No evidence of pupillary hypersensitivity to an anticholinergic
mydriatic drug was found in patients with Alzheimer disease or any evidence
that this putative hypersensitivity could be used as an early, simple
diagnostic test for Alzheimer disease.
