Arteritic and Nonarteritic Ischemic Optic Neuropathy (M1)

Question 1

What is the equation for the normal ESR of a male? 1. Female? 2

Answer 1

1. age/2

2. (age+10)/2

Question 2

What does FANG show for NAION?

Answer 2

delayed filling of optic nerve (useful in differential)

Question 3

What makes giant cell arteritis an ocular and medical emergency?

Answer 3

myocardial infarction and aortic dissections are potential complications

Question 4

What are the rules to safely make a diagnosis of NAION?

Answer 4

1. over 40yo
2. vascular risk factors, no hx cancer
3. only one eye symptomatic (sudden VA loss)
4. no eye/orbit pain
5. +RAPD, +optic disc swelling
6. no hard exudates
7. other eye normal with crowded disc
8. VF loss
9. no worsening of VA past one week

Question 5

What is the pathogenesis of arteritic ION?

Answer 5

1. occlusion or infarction of blood supply at laminar cribrosa
2. immunologic disorder
3. luminal obstruction

Question 6

What is the epidemiology of Giant cell arteritis?

Answer 6

1. over 60 yo
2. females
3. caucasians

Question 7

What is the most common cause of vision loss when a patient has Giant Cell Arteritis?

Answer 7

infarct of prelaminar optic nerve (AION)

Question 8

What are the tests that are useful in screening for temporal arteritis (Giant cell arteritis)?

Answer 8

1. ESR

2. CRP

Question 9

What are the signs of a positive temporal artery biopsy?

Answer 9

1. disruption/fragmentation of internal elastic lamina from inflammation
2. swollen endothelium
3. patchy degeneration of smooth muscle cells in intima
4. granulomatous inflammation of arterial wall
5. fibrosis, hyalin thickening, and thrombosis leading to vessel occlusion

Question 10

What is the treatment in which you open the meningeal sheath of the optic nerve and lyse the subarachnoid adhesions to relieve pressure at the nerve head? 1. What does this do? 2

Answer 10

1. Optic Nerve Sheath Fenestration (ONSF)

2. improve blood flow to optic nerve and improve hemodynamics postoperatively

Question 11

What are the differential diagnoses for NAION?

Answer 11

1. optic neuritis secondary to infection
2. infiltrative optic neuropathy
3. diabetic papillitis

Question 12

What are the systemic diseases associated with arteritic ION?

Answer 12

1. Giant cell arteritis

2. Rheumatologic and inflammatory disorders

Question 13

How long does it take disc edema and hemes to resolve in NAION?

Answer 13

2-8 weeks

Question 14

What is the recurrence rate of NAION? 1. What is the likelihood of an attack in the other eye? 2

Answer 14

1. 5%

2. over 50% after 10yrs

Question 15

What is giant cell arteritis a response to? 1. What arteries does it affect (and which specific ones impact vision)? 2.

Answer 15

1. autoimmune response to arterial elastic tissue

2. medium and large arteries (temporal, occipital, ophthalmic, posterior ciliary, central retinal)