The Great Fluorescein Crisis
Let’s talk about fluorescein, the prized jewel of emergency physicians investigating a patient with an eye problem. The recent shortage of impregnated fluorescein strips has left many practitioners without much recourse. Wood’s lamps across the country are collecting dust alongside prescription pads and direct ophthalmoscopes. If you do come across some of that orange gold, better make it count.
Here are some tips for using what precious fluorescein you have left, and what to do if you’re all out.
Do not use a fluorescein strip on every patient with an eye problem
In an emergency setting, fluorescein is only useful for 2 things: Diagnosing corneal pathology and wound leaks (open globes or leaking surgical wounds). Corneal abrasions and ulcers will be painful the vast majority of the time. That’s why they come to the ED. If there is no history of trauma and the patient does not have eye pain, there is no need to use fluorescein . A patient with flashes and floaters does not need a thorough fluorescein exam. There is nothing sadder in these trying times of fluorescein shortage than a wasted stick.
2. look at the patient
This may sound silly, but you can tell a lot about the surface of a patients eye (conjunctiva, cornea) by taking a pen light and comparing one eye to the other. Look at the healthy eye first. You should be able to see iris detail, its color and reactivity. You can see the shape of the pupil. In other words, it should be crystal clear. If everything looks clear and there is no conjunctival injection or history of trauma, don’t use a fluorescein strip.
Now look at the bad eye. Is it cloudy? Can you make out features of the iris? Are you having trouble seeing the pupil? Is the patient’s soul obscured by a dirty window? There may be some corneal pathology. If the patient is also in pain, your pre-test probability of a corneal problem is high enough to break out the fluorescein.
3. Use a topical anesthetic prior to fluorescein
Lots of people come in with eye pain. A great way to determine if this pain is due to a cornea problem is administering proparacaine. Pain from a corneal abrasion or dry eye will magically melt away with anesthetic. At this point, you have 2 options:
Use fluorescein OR Don’t use fluorescein
If a patient comes in with severe, stabbing eye pain which resolves completely with topical anesthetic, you can administer fluorescein to confirm your preliminary diagnosis of a corneal abrasion. I would consider this a good use of fluorescein. On the other hand, if you are hoarding your last few sticks of dye away from your thieving colleagues, it would be reasonable to look at the clinical findings in front of you and make the diagnosis without using fluorescein. This is ok too. If an emergency physician called me and said, “I have a 39 year old male who got poked in the eye playing basketball, noticed immediate pain which resolves with topical anesthetic,” I would first ask if there are any signs of an open globe injury (is the vision reasonably good, is the anterior chamber formed, does the patient have iris or retinal tissue extruding from a gaping scleral wound). If there is no concern for an open globe, I’m probably not going to even ask about fluorescein staining. It sounds like a textbook corneal abrasion. Start a topical antibiotic and have them follow up with an eye doctor within 48 hours.
4. Use a fluorescein solution
One option is fluorescein/topical anesthetic combination. It’s numbing and staining all at once! What a deal! It’s also a little more expensive than strips (~50 bucks for a 5ml bottle) and some of them are also on back order. Flucaine (fluorescein + proparacaine) also seems to be on back order or at least very difficult to acquire. Your best bet for getting your hands on some fluorescein would be the fluorescein + benoxinate hydrochloride solutions. The FDA lists the brand Flurox as unavailable, but Altafluor and Fluress are still available. The benefit of using a 5 ml solution is that you can get 100 drops out of it. That’s 100 eye problems, which is, of course, a nightmare scenario for most EM practitioners, but at least you can rest assured you won’t run out of fluorescein.
The only downside to using drops is that it floods the eye with way more fluorescein than you need. Bathing the eye with too much dye can make it difficult to discern fine corneal detail. However, as a non-ophthalmologist, you should never feel obligated to put the words “fine corneal detail” together in a sentence, so by all means, drop away.
the good news
The great fluorescein shortage of 2018 may be coming to an end. Several manufacturers estimate that fluorescein will be back in production by the 1st or 2nd quarter of 2019, although they may just be stringing us along. In the meantime, hoard your sticks and use them judiciously.