Abstract
The pupil dilation response to tropicamide has been proposed as a simple test for
demonstrating the central cholinergic deficit present in Alzheimer's disease (AD).
We examined this response in 20 patients with clinically diagnosed mild probable AD
and in 20 unrelated, cognitively intact, age-matched controls. A marked increase in
pupil diameter was observed within 30 minutes in both groups. Differences between
the groups did not attain statistical significance. The ability of the proposed test
to discriminate between AD patients and healthy controls may be influenced by experimental
procedures and by the ethnic background of the subjects under study. At present the
pupil dilation response to tropicamide cannot be considered a useful diagnostic aid.
