Novel Drug Delivery System for the Management of Wet AMD - Episode 2

Imaging Modalities in Wet AMD

May 17, 2021
Carl Regillo, MD, Thomas Jefferson University School of Medicine

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Diana Do, MD, Stanford University School of Medicine

Role of imaging modalities in the diagnosis and monitoring of age-related macular degeneration (AMD).

Diana Do, MD: When you’re evaluating a patient with new-onset wet macular degeneration, what imaging modalities do you recommend we utilize?

Carl Regillo, MD: That’s a great question. These patients are being referred to a retina specialist because there’s a suspicion, or it’s obvious, that the patient has turned wet in 1 eye, let’s say. The patient usually recognizes it with some new blurring of the vision, hopefully not too severe by the time they get to us. They often go to their primary eye care provider, general ophthalmologist, or optometrist, complaining of a vision problem. They suspect it based on the examination. They look at the retina, usually with a dilated pupil, and they see signs of wetness, exudation, sometimes lipid exudate, blood, fluid, thickening of the macula. Then they send the patient to us. 

Sometimes they may have already done a diagnostic test called an OCT, optical coherence tomography. When they get to us, they’re going to get that dilated eye and retinal examination. We’re going to look at the macula and see signs of exudation, so we’ll know that the patient has wet AMD. The examination alone does the trick. However, OCT is a test we highly rely on, both in terms of confirming the diagnosis and knowing exactly what the patient has at baseline pretreatment, to measure the treatment response once treatment is initiated. OCT is the most important diagnostic test we have, and we use it to diagnose and monitor treatment of wet AMD. 

There are a few other tests that we will sometimes use. OCT is not an old test; it’s been around less than 20 years. Before that we did, and still do to this day, a fluorescein angiogram, a series of pictures of the eye after an intravenous injection of the fluorescein dye. That will show us the leaking choroidal vascular membrane, or choroidal vascular process, in the macula. We can tell the size and location of the neovascular complex based on the fluorescein angiogram. It’s not essential, but it’s often done at presentation, so it’s a test we’ll sometimes get at the beginning, rarely later, but usually at the first consultation.

There’s 1 newer test. It’s not really standard of care, but it can be useful to pick up these neovascular complexes. That’s OCT angiography. It’s a noninvasive, no-dye-involved diagnostic test done essentially with the same equipment, OCT, but it will show abnormal blood vessels. It’s a little harder to interpret, not necessarily part of standard care. This equipment is often in academic centers but not necessarily all the offices that retina specialists practice in. OCT for sure gets done, a fluorescein angiogram maybe, but rarely an OCT-A, or OCT angiogram. Is that something you do too? Do you get fluorescein angiogram on a regular basis when you first see the patient?

Diana Do, MD: I agree that OCT imaging is the mainstay of diagnosis and follow-up, but there is still a key role for fluorescein angiography, especially during the initial diagnosis, to make sure there are no other masquerading syndromes that might be contributing to the vision loss that could offer an alternative treatment. Fluorescein angiograms can also be useful if, say, the patient is not responding to your treatment. Repeating a fluorescein angiogram can help elucidate if something is changed, and that might alter what you recommend.

Carl Regillo, MD: Thank you for watching this HCPLive® Peers & Perspectives®. If you enjoyed the content, please subscribe to our e-newsletter to receive upcoming Peers & Perspectives® and other great content right in your in-box.

Transcript Edited for Clarity

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