AION vs NAION
Toxic
Fundus
Genetic Optic Neuropathy
Misc.
100

What differentiates AION and NAION?

Arteritic means inflammatory in etiology: AAION

Small vessel ischemia: NAION

100

These vitamin deficiencies are associated with optic neuropathy

B12, folate, thiamine (think associated symptoms)

100

In acute optic neuritis, this is the most common fundus finding

Normal


100

This is the usual presentation of Leber Hereditary Optic Neuropathy (symptom, course speed, age)

Painless, acute vision loss in one eye, that progresses to the other eye within weeks to months in teenage to early 20s most commonly

100

Most common diagnostic imaging evaluations that should be done after fundoscopic evaluation for nearly all patients with suspected optic neuropathy (2)

MRI w/ and w/o orbit with fat saturation & Optical Coherence Tomography (OCT)

200

These are the different demographic/symptom presentations associated with AION and NAION

NAION: HTN, OSA, DM with sudden, painless vision loss usually in one eye

AION: age > 50, painful vision loss, systemic symptoms (myalgia, weight loss, malaise), elevated ESR/CRP (>80%)


Bonus: what disease is highly associated with GCA?

200

These TB medications can be associated with toxic optic neuropathy

Ethambutol and Isoniazid

200

Toxic or Nutritional optic neuropathy most often has these fundoscopic finding

Bilateral temporal optic disc pallor


200

Most common mutations in Leber Hereditary Optic Neuropathy

MT-ND4, ND1, ND6 - affect electron transport chain complex 1 

200

This condition is characterized by optic atrophy, spastic paraplegia, and cerebellar signs

Autosomal Dominant Optic Atrophy

300

These are the treatments for AAION and NAION

AAION: High dose steroids (methylprednisolone 1g daily x 5 days) prior to biopsy --> 33-50% will progress to other eye if not treated

NAION: treat risk factors --> ASA not found to be helpful

300

This is the most common presentation of toxic and nutritional neuropathies

Bilateral, symmetric, central vision loss and dyschromatopsia

300

What fundus finding is found for a “disc at risk” for NAION

reduced cup-disc ratio (<0.5 normal vs <0.2 concerning); crowded disc


300

Most common mutation in Autosomal Dominant Optic Atrophy 

OPA1 - affects mitochondrial metabolism and causes retinal ganglion cell death

300

These are risk factors for Posterior Ischemic Optic Neuropathy 

Spinal surgeries, radical neck dissections, prolonged surgical duration, prone position, intra-operative hypotension

400

This is the timeframe in which temporal artery biopsy should be performed and if negative, these additional studies can be done if suspicion remains high (2)

1. Within 2 weeks of steroid initiation

2. Color doppler ultrasound or MRI of cranial/extracranial vessels

400

This industrial toxin causes rapid, severe bilateral visual loss and may be associated with metabolic acidosis

Bonus: How do you treat?

Methanol

Bonus: Fomepizole or ethanol

400

Optic disc swelling with peripapillary hemorrhages is characteristic of this optic neuropathy

NAION 

Often inferior/superior preference for swelling

400

Type of vision loss in Leber Hereditary Optic Neuropathy

central, severe --> sparing peripheral vision

400
Phosphodiesterase-5 inhibitors predispose patients to this type of optic neuropathy

NAION

500

These are the thus-far proven long-term steroid-sparing treatments for GCA (2) with MOA

Tocilizumab - IL-6 inhibitor

Methotrexate - dihydrofolate reductase inhibitor

500

This antibiotic can cause toxic optic neuropathy, particularly in renal dysfunction

linezolid

500

Leber hereditary optic neuropathy shows what fundoscopic finding

hyperemic, pseudo-edematous optic nerves with peripapillary telangiectasias


500

Leber Hereditary Optic Neuropathy can be rarely occur with this other neurologic syndrome

Multiple Sclerosis

500

This is the most common/characteristic finding of radiation-induced optic neuropathy

juxtachiasmal enhancement of right optic nerve

Can precede the neuropathy by months; usually 50 Gy treatments --> nasopharynx, nasal cavity, and paranasal sinuses, orbital meningiomas