I am seeking some additional opinions regarding the connection between the iodine/shellfish allergy and ICG dye. I'm interested in amending our Informed Consent form to exclude a line about allergy to shellfish and/or iodine as a reason to avoid doing an ICG angiogram.

After reading the threads on Optimal, my understanding is that doing an ICG dye test on a patient who admits to having an iodine or shellfish allergy is not uncommon and presents no danger to the patient anymore than any other injected substance, would you all agree? Are you doing ICGs on these patients? Do you even ask the patients if they are allergic to those substances? We've been doing ICGs for about a year and have had only a few patients that have admitted to an allergy. We've erred on the side of caution and avoided doing the test. I'm questioning the validity of that.

Also, has anyone here ever witnessed any allergic reaction to ICG at all? Is it safe to assume that we would treat it the same as a reaction to FA dye? Benadryl is our first line of defense most of the time.

So if anyone can shed some additional light here, I'd appreciate it. I'm just looking for that extra bit of reassurance before I make any changes to our protocol.

Thanks!

Jennifer Lummis, CRA, COA

Maine Eye Center

Portland Maine

PS: The new website is great and this forum is wonderful. Kudos to all who worked on it!

 and Welcome Aboard!

A pretty big topic for your first post, but, if you are going to get help from us who are out in the field, then, a big bite deserves a big piece of pie!

We too have been delivering ICG dye, in conjunction with some FA patients to look for choroidal leakage in those Wet AMD patients with subretinal leakage, the same as you. Even so, for those with patients who present with Central Serous Retinopathy in the last 2-3 years.

Our formula utilizes only ½ of the 25 mg ICG dial contained inside the light shielded bottle, and therefore only 12.5 mg of dye is administered into the patient.

The package insert is of course no news to you, but it states ‘no more than 5% of sodium iodide’ ~ mainly used as a preservative. So, ½ of that 1.25 mg per vial, leaves only 0.625 mg of that threatening sodium iodide is actually going into each of our patients.As for having a shellfish allergy in these cases, I have this for experience.

On careful interview with the patient, there are many who are deathly allergic to shellfish, and as a ‘Mainard’ you would have certainly heard this in your work up in Portland, and myself as a former 'Cape Codder', I have heard all of those allergic concerns as well, about having an ‘arrest’ after just the hint of a taste of a shrimp or lobster on the end of a fork. When encountering these types of patients, I omit them outright, and just perform an FA test, and go on.

Though, in the past 10 years of performing simultaneous, FA + ICG procedures I can remember maybe only ~3 patients that admitted they had some sort of allergy to shellfish for the past 30 years, and hadn’t touched any shellfish at all. Then, with careful questioning, I learned that their supposed ‘allergy’ was really an ‘unknown’. One patient said maybe it was the ‘Sherry’ in the chowder, one patient said that it might have been the ‘MSG’ in the seafood bisque, etc. I then proceeded to tell them that the Sodium Iodide in this ICG formulation was of a very small concentration and, that it was used mostly as a ‘preservative’ and is an ancillary additive. Then, confirmed that they would like to proceed with the test, and did so without any indicence.In reading your statement above,

I would have to agree that we have performed ICG dye tests on that patient that admitted to some sort of shellfish allergy, but, the patient knew that this might fall into the same allergy that they experienced with shellfish ‘a long time ago’, and, would they let us perform it on them to diagnoses their disease; and they all had agreed (to the best of my knowledge), and gave written consent in order for us to proceed.

However, keep in mind that you are always putting the patient at risk, with ICG, as you would with any other injected substance for diagnostic use.

In our office, we have never had a patient have any kind of allergic response to intravenous injection of Indocyanine Green Dye, for diagnostic purposes.

For those with a history of allergic reaction of a previous FA, or ICG dye, we opt to pre-medicate the patient with a combination of 25 mg Benadryl, and 10 mg Compazine, PO. Then, we wait 20 minutes, and then proceed with the FA/ICG dye test.

For further prevention, we also push only 2/3rd dose, and push it S L O W L Y.I am sure that Ethan will wake up in Isreal and jump onto this thread, as well as Mr. Kelly, and I look forward to their contributions as well.

Best of Luck,

Jim Soque