Approach to Acute Vision Loss

Question 1

Is the optic nerve found more on the medial or lateral side of the eye?

Answer 1

Medial

Question 2

Scotoma

Answer 2

Patch of vision loss that you can’t see around

Question 3

What does the
1. Numerator
2. Denominator
mean in 20/20 vision

Answer 3

1. The distance at which the test was taken

2. Distance at which the letter subtends 5 mins of arc (what a normal person can see at)

Question 4

Amaurosis Fugax

Answer 4

Transient darkening of vision lasting 10 mins or less
Shade, tunnel, blur - points to hypoperfusion
Have to find the occlusion causing the hypoperfusion
Refer to stroke clinic!! High chance of stroke in the next week

Question 5

Central Retinal Artery Occlusion

Answer 5

Blockage of the artery (with cholesterol, Ca, clot, talc, air, fat, etc)
Poor prognosis for visual recovery
TPA doesnt work (increases risk of ICH)
Risk of other ischemic events
Future risk of new aberrant blood vessels forming in the eye called neovascularization
Needs anticoagulation

Question 6

All patients with central retinal artery occlusion should be screened for…

Answer 6

Giant cell arteritis

Question 7

Posterior vitreous detachment

Answer 7

As we age the vitreous jelly in the posterior chamber breaks down
Can cause floaters and flashing lights (from tugging on the retina)
Not an emergency
Not going to fix itself, but brain will adjust to a new normal

Question 8

Retinal detachment

Answer 8

When the retina peels off the back of the eye
If caught early in the periphery it can be fixed
Like a dark curtain coming down

Question 9

Relative afferent pupillary defect

Answer 9

When you shine 100% light into one eye but dont get 100% response
Optic nerve problem
Some signal is being lost on its way to the edinger-westphal nucleus (normally controls parasympathetic constriction)

Question 10

2 important things to look for when looking in the eye

Answer 10

Borders of the optic disc

If you can see the vessels

Question 11

Giant cell arteritis (what is it, presentation, treatment)

Answer 11

Also called temporal arteritis
Vasculitis of medium/large vessels (ophthalmic artery and vertebral arteries)
Common presentation: unilateral vision loss (from ischemic optic neuropathy), temporal headache, jaw claudication)
Bloodwork will be positive for inflammatory markers
Treatment: rapid initiation of IV steroids to reduce inflammation and prevent bilateral irreversible vision loss