How to test for a relative afferent pupillary defect (RAPD)

摘要

This article explains how careful examination of the pupil light reflex can reveal valuable information about the afferent (optic nerve) and efferent (oculomotor nerve) light reflex pathway, and hence the functioning of these two cranial nerves.The “swinging light test” is used to detect a relative afferent pupil defect (RAPD): a means of detecting differences between the two eyes in how they respond to a light shone in one eye at a time. The test can be very useful for detecting unilateral or asymmetrical disease of the retina or optic nerve (but only optic nerve disease that occurs in front of the optic chiasm).