anisocoria

Case: A 22-year-old male is admitted to the ICU with exacerbation of asthma. The patient has been started on intravenous steroids and aerosolized bronchodilators. Medical student reports the finding of unilateral mydriasis (anisocoria).

Discussion: Pharmacologic pupillary changes are very common in the ICU. Commonly used drugs in the ICU may cause mydriasis. It occurs due to different drugs, either by stimulation of the sympathetic innervation of the dilator pupillae or inhibition of the parasympathetic innervation to the sphincter pupillae. These drugs include atropine, homatropine, phenylephrine, clonidine, and glycopyrrolate.

Aerosolized anticholinergic drugs (eg, ipratropium) administered through ventilator masks may produce unilateral mydriasis.

Pharmacologic mydriasis is, by definition, asymptomatic.

# ophthalmology

#pulmonary

#pharmacology

References:

1. Iosson N. Images in clinical medicine. Nebulizer-associated anisocoria. N Engl J Med 2006; 354:e8.

2. Lust K, Livingstone I. Nebulizer-induced anisocoria. Ann Intern Med 1998; 128:327.

3. Openshaw H. Unilateral mydriasis from ipratropium in transplant patients. Neurology 2006; 67:914.