RAPD

RAPD = MARCUS GUNN PUPIL

EXAMINE WITH LIGHTS OFF

NORMAL PUPILS:

React to light, then relax (a bit…)

Each time light is swung onto pupil they constrict, then relax (a bit)

Then dilate when the light is removed

RAPD

Pupils equal in size, BOTH react to light

BUT:

BOTH pupils dilate when light is swung across to affected eye

ie: Compares RELATIVE strengths of signals from each eye going to brain

So you’ll miss it if you don’t do the swinging light test

LOCALISES PATHOLOGY TO THE PRE-CHIASMA

RETINA: CRAO, CRVO

OPTIC NERVE: Optic Neuritis, Ischaemia, Compression, (& Assymetric glaucoma)

COMPLETE APD

NO pupil reaction in either eye when light shone in affected eye