By Wadih Zein, MD

Physiologic Miosis of affected pupil    Horner’s syndrome    Iritis    Argyll-Robertson pupil    Pharmacologic miosis    Long-standing Adie’s tonic pupil Fixed dilated pupil    Traumatic    Adie’s tonic pupil    Acute angle-closure glaucoma    Pharmacologic mydriasis    Third nerve palsy

Anisocoria is a cause of concern for any clinician since some of the associated conditions are sight- or even life- threatening. The first step towards a correct diagnosis is to determine if the pupillary response in each eye is normal.

Physiologic anisocoria: the majority of patients with anisocoria have a physiologic difference in the size of the two pupils. The patient usually has no symptoms and may not be aware of the difference. Response to light and near testing is usually normal and difference in size of the two pupils is usually less than 2mm.

Horner’s syndrome: can be congenital or acquired (trauma, surgery, migraine, stroke, lung tumors, and demyelinating diseases). Ptosis, miosis, and facial anhydrosis are noted in Horner’s syndrome; the congenital disease is also associated with iris heterochromia. Response to light and near testing is usually intact although anisocoria is greater in dim light. Instillation of 1-% hydroxyamphetamine is used to determine the location of the lesion.

Iritis: can be traumatic, idiopathic, or associated with systemic disease. Patients usually complain of pain, photophobia, and red eye. Cells and flare are noted in the anterior chamber and ciliary injection is usually present; posterior synechiae can also develop.

Argyll-Robertson pupil: is a light-near dissociative response most commonly associated with neurosyphilis. It is usually bilateral and patients do not experience symptoms directly related to it. Pupils are assymetrical, irregular, and react poorly to light but constrict normally to a near stimulus.

Pharmacologic miosis: most commonly secondary to unilateral instillation of a miotic drop for the treatment of glaucoma. Pupil will react poorly to light and pharmacologic dilatation.

Traumatic pupillary rupture: patient usually has no symptoms; there is a history of trauma and the slit–lamp exam reveals iris atrophy, sphincter rupture, or synechiae in the affected eye.

Adie’s tonic pupil: more common in females and usually patient is asymptomatic. Most cases are idiopathic but associations are present with viral infections, neuropathies, or trauma. Pupil is fixed and dilated with poor response to light and near. Depressed deep tendon reflexes are also associated with this condition.

Acute angle-closure glaucoma: patients with ACG usually complain of eye pain, blurred vision, haloes, and nausea. Exam reveals an edematous cornea, IOP is elevated, pupil is fixed mid-dilated, and gonioscopy reveals a closed angle.

Pharmacologic mydriasis: common culprits include the use of mydriatic agents, scopolamine patches for motion sickness, and contact with belladona plants.

Third nerve palsy: sudden ptosis, diplopia, and pain are some of the symptoms of CN III palsy. Pupil is fixed-dilated, and extraocular motility will be restricted.