Optic atrophy

Question 1

Optic atrophy

Answer 1

Examine this woman’s eyes.

Question 2

Clinical signs of Optic atrophy

Answer 2

• Relative afferent pupillary defect (RAPD): dilatation of the pupil on moving the light source from the normal eye (consensual reflex) to the abnormal eye (direct reflex): Swinging light test (Marcus- Gunn pupil)
• Fundoscopy: disc pallor
• Extra points Look for the cause.

Question 3

Causes of Optic Atrophy On examining the fundus

Answer 3

1. Glaucoma (cupping of the disc)
2. Retinitis pigmentosa
3. Central retinal artery occlusion
4. Frontal brain tumour: Foster–Kennedy syndrome (papilloedema in one eye due to raised intercranial pressure and optic atrophy in the other due to direct compression by the tumour)

Question 4

Causes of Optic Atrophy At a glance from the end of the bed

Answer 4

1. Cerebellar signs, e.g. Nystagmus: MS (internuclear ophthalmoplegia), Friedreich’s ataxia (scoliosis and pes cavus)
2. Large bossed skull: Paget’s disease (hearing aid)
3. Argyll–Robertson pupil: Tertiary syphilis

Question 5

Causes of Optic Atrophy

Answer 5

PALE DISCS
1. Pressure^: tumour, glaucoma and Paget’s
2. Ataxia: Friedreich’s ataxia
3. LEber’s optic atrophy
4. Dietary: ↓B12,
5. Degenerative: retinitis pigmentosa
6. Ischaemia: central retinal artery occlusion
7. Syphilis and other infections, e.g. CMV and toxoplasmosis
8. Cyanide and other toxins, e.g. alcohol, lead and tobacco
9. Sclerosis^: MS
(^ denotes commonest cause)