Horner syndrome and Cocaine

Cocaine blocks reuptake of norepinepherine that is normally released from nerve endings. In a sympathetic lesion, norepinepherine is not released.

little or no effect

dilation

• Place not more than 2 drops of cocaine hydrochloride 10% in both eyes (2% for infants and children,4% and 5% can also work for adults)
• Measure anisocoria 50-60 minutes later
• 0.8 mm or greater anisocoria after the cocaine is highly suggestive of Horner syndrome

pupil held by membrane, scar or aberrant innervation Image