Background: To describe 4 patients with bilateral tonic pupils in neurosyphilis.
Cases: Four young men had pupillary abnormalities, which involved irregular shapes, large sizes, tonic reactions, and vermiform movements of both pupils with light-near dissociation. Cholinergic supersensitivity defined bilateral tonic pupils.
Observations: Neurosyphilis was diagnosed in these patients on the basis of ocular and laboratory findings.
Conclusions: Bilateral tonic pupils may be important as initial findings in neurosyphilis. We conclude that patients with bilateral tonic pupils should undergo serologic tests for syphilis.