Acute monocular vision loss is often an ophthalmologic emergency! Use this nifty graphic to help you differentiate between the most dangerous pathologies, and to remind you how to initiate their medical management!
These are the key take-homes for today's pearl:
-Ophtho should be consulted for all 6 of these pathologies of monocular vision loss. However, it is IMPERATIVE that they be consulted ASAP for CRAO, CRVO, and retinal detachment. That is because the only treatments we have for these pathologies are administered by ophtho, not by the ER.
Ocular chamber paracentesis, intra-arterial tpa, or intra-ocular antihypertensives may be administered by ophtho for CRAO
Depending on exam findings (they may also ask for "fluorescein angiography" to differentiate ischemic vs. nonischemic) in suspected CRVO, ophtho may give intra-ocular steroids, hypotensive agents, biologic agents, or even perform surgery.
EM used to give ASA to these pts. Antiplatelet agents have since been found to be harmful. The only thing you need to do while waiting for your opthalmologist is to try to control their hypertension.
We may have all learned that "mac-on" retinal detachment is more of a surgical emergency than "mac-off" (which is technically true, but will only differentiate whether the pt goes to the OR today vs. in 3 days - so they are still both often operative!) however our US and exam is not as good at differentiating the the two, so play it safe, and consult ophtho assuming it is "mac-on" every time... in case it is.
On a similar tangent, if you believe you note posterior vitreous detachment on your POCUS, but no retinal detachment, they should still see an ophtho ASAP, because there is a large co-incidence of the two, and often PVD proceeds RD by just a few days.
-For the painful monocular vision losses (glaucoma, optic neuritis, and GCA) we can feel a little less helpless and start treatment before ophtho arrives!
High dose methylpred for suspected GCA w/vision loss (500-1000mg IV )
High dose methylpred for suspected optic neuritis (dosing per neurology)
For suspected angle closure glaucoma, give topical optic beta blockers (timolol) and alpha agonists (such as brimonidine or apraclonidine). We can also start systemic (PO or IV) acetazolamide (if ok kidney function, chose methazolamide if poor kidney function) if the IOP is not coming down with topicals. Next step after that would by IV mannitol/glycerol, but your friendly ophthalmologist will guide you on that.
We should avoid giving pilocarpine which can exacerbate certain ocular conditions
Also note that if the pt has had cataract surgery in the affected eye, he/she cannot possible be in angle closure (a helpful tip as these pts may have the "steamy" cornea we associate w/acute angle closure glaucoma).
