Dextromethorphan protects retina against ischemic injury in vivo.

Retinal ischemia was induced in rabbits by increasing intraocular pressure above systolic blood pressure for 60 or 75 minutes, and retinal function was monitored by electroretinography. Pretreatment with intravenous dextromethorphan, a nonprescription antitussive and selective antagonist of N-methyl-D-aspartate receptors, enhanced greatly the post-ischemic recovery of b-wave amplitude. Dextromethorphan may prove to be useful clinically in the management of retinal ischemic disease.