A lesion of the sympathetic supply to one eye causing unilateral miosis (small pupil), slight ptosis, and anhydrosis.
Causes are given in Table 7.13.
The condition presents with unilateral pupillary constriction (miosis) with a slight ptosis and anhydrosis. The conjunctival vessels may be injected. Associated features may include a hoarse voice (due to either recurrent laryngeal nerve palsy or lower cranial nerve involvement), or signs in the neck, chest or hands pointing to the level of the lesion.
A chest X-ray or MRI brain may be indicated to identify the underlying lesion. Treatment is directed at the underlying cause.