A 58-year-old patient with anisocoria has the following pupil measurements: Light  room    OD:  3.5mm     OS: 5.5mm Dark room     OD:  4.0mm        OS: 8.0mm You administer 4% cocaine and no dilation occurs in the right eye.  After 48 hours, you re-test  the patient with 1% hydroxyamphetamine (Paradrine) and the pupil does not dilate.

The most likely diagnosis is:

a. Horner’s syndrome: first order neuron b. Horner’s syndrome: second order neuron c. Horner’s syndrome: third order neuron d.  Adie’s pupil

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