Relative afferent pupillary defect

Question 1

What is another name for a relative afferent pupillary defect?

Answer 1

Marcus-Gunn pupil

This condition is identified during the ‘swinging light test’.

Question 2

How is a relative afferent pupillary defect identified?

Answer 2

‘Swinging light test’

This test involves moving a light between the eyes to observe pupillary responses.

Question 3

What causes a relative afferent pupillary defect?

Answer 3

Lesion anterior to the optic chiasm

This includes conditions affecting the optic nerve or retina.

Question 4

What happens to the affected eye when light is shone on it during the test?

Answer 4

It appears to dilate

This is observed in comparison to the normal eye.

Question 5

What are two potential causes of a relative afferent pupillary defect related to the retina?

Answer 5

• Detachment
• Optic neuritis (e.g., multiple sclerosis)

These are common conditions that can lead to the defect.

Question 6

What is the pathway of the pupillary light reflex?

Answer 6

Afferent: retina → optic nerve → lateral geniculate body → midbrain
Efferent: Edinger-Westphal nucleus (midbrain) → oculomotor nerve

This pathway describes how light stimulus is processed and leads to pupil constriction.