Unit 3: Pupil Abnormalities, Facial Nerve Palsy & Ptosis
2: Clinical Examination of Pupils
Pupil Responses
text transcript
video credit: Sam Tapsell
Test the direct pupil response:
Shine a light on one eye and observe pupil constriction in the same eye, while the patient fixates a distant target.
Test the consensual pupil response:
Shine a light on one eye and observe pupil constriction in the other eye.
Test the near pupil response:
Get the patient to fixate a distant target then a near target and observe pupil constriction (the near response can still be assessed in blind patients by asking them to look at their thumb when it is held in front of their face).
Test for an RADP pupil response:
Swing the light from one eye to the other but allowing 3 seconds of illumination per eye. When the light is swung from the healthy eye (both pupils constricted) to the defective eye, both pupils will constrict less well and in some cases may paradoxically appear to dilate.
An RADP indicates asymmetric optic nerve or retinal disease, because it reflects an asymmetric reduction in the afferent signal. As the efferent pathway is intact, the affected eye retains normal pupil constriction when light is shone in the other, healthy eye. Mild retinal disease will not cause an RADP, but extensive retinal disease may.