EPISODE 19: Diana Do, MD, and Deepak Sambhara, MD, FASRS, patient identification and risk stratification when determining treatment for geographic atrophy.
What follows is a lighty edited transcript of the conversation:
Diana Do, MD: Hi, welcome to the Geographic Atrophy Video Channel. I'm Dr. Diana Do, and today I'm joined by my retina colleague and expert, Dr. Deepak Sambhara. Welcome, Deepak.
Deepak Sambara, MD, FASRS: Hey, Diana. Thanks for having me.
Dr. Do: We see a lot of patients with age-related macular degeneration (AMD), especially the advanced dry form, which is geographic atrophy (GA). Can you tell us about how do you manage patients with GA, and what type of treatment options are available?
Dr. Sambhara: It's hard to appreciate where we're at right now without taking a peek back to see where we've come from. And so I, just like you, 5 years ago plus, didn't really have anything in our toolkit to offer patients who suffered from GA. And folks with GA tend to be some of the most needy patients who have organic disease and who are actively losing vision. So this has been a huge gap in our practice, not having anything we could offer those patients until we had complement inhibitors that hit the market about 3 years ago. And I think with the advent of complement inhibitors, we've now kind of opened up access for treatments to patients. But I think it's also important to understand that not every patient with GA is necessarily a good candidate for complement inhibitors either.
When I think about patients who have GA, I always like to start by looking at historical imaging if available. We know that GA is a very heterogeneous disease and it can move slowly in some folks, it can also move a little quicker in others. I oftentimes like to refer back to historical imaging to get a better idea of what the cadence of progression looks like. I also like to look at the patient's fellow eye to have a better understanding of what we're working with, because oftentimes a fellow eye that doesn't see well creates a very motivated patient who may be looking for treatment.
Now, to answer your question as to what's available now, it's really interesting because we do have complement inhibitors, treatments of GA. And that, in my practice, has been a game changer because now, for once, we're able to offer interventions and active treatments for patients who otherwise, prior to the advent of complement inhibitors, had nothing for us to offer outside of watchful waiting and conservative care.
Dr. Do: That's a wonderful review of what we have available. And I wanted to touch upon the complement inhibitors. We have two that are FDA approved. Both are delivered via intravitreal injection and have to be given fairly frequently, every 1 to 2 months ongoing. How do you identify which patients? You mentioned some that may have lost 1 eye already are very motivated to save their good eye. But is there a particular lesion? Is the GA involving the foveal center or is it threatening the center? How do you identify those patients?
Dr. Sambhara: I think that's a great question. And as we've had more interventional GA studies that have come to fruition, whether they've led to FDA-approved products or not, it's actually increased our knowledge about the disease. So we can look back at the early lampalizumab trials, or we can even look at the studies for PEG and ACP, OAKS and DERBY and the GATHER programs, respectively. And what we've learned is that GA progresses a little bit differently than what our BCSC textbooks might've taught us in residency. And because we have imaging associated with all of those study visits for those trials I just outlined, we now can identify risk factors via multimodal imaging that can help better stratify those patients with GA who might be quicker progressors compared to the slow growing patients. And I definitely do appreciate multimodal imaging as a very big part as to, or a very big part of how I identify a good patient or a good candidate for treatment.
Patients who have multifocality, perilesional hyperautofluorescence, those with diffuse trickling lesions on autofluorescence, those are all prognostic features of quicker-growing GA lesions. And those are patients who I want to have the conversation with early. Also, non-subfoveal lesions, we've learned from both the GATHER programs as well as the OAKS and DERBY programs, grow slightly faster. We know that patients sometimes may not even be symptomatic if their foveal center point's not involved. And for those patients, I think having the discussion and at least letting them know about the pathology that I see is a great starting point. It's not my job to twist somebody's arm and convince them to commit to intravitreal treatments for Ga because, as you said, they can be quite burdensome. But if I can educate a patient on the disease that they have by showing them their images, it can at least create a culture of compliance from which patients may commit to sooner follow up than they otherwise would've.
Dr Do: I really liked how you talked about multimodal imaging. And many retina specialists, of course, use OCT as a daily tool on all of our patients. But you also mentioned fundus autofluorescence. How often would you use fundus autofluorescence in a GA patient, especially if you've started complement inhibitors?
Dr. Sambhara: So that's a fantastic question. And in my particular practice, I have autofluorescence capabilities only at my main campus and I travel to about 5 satellite locations. So I try and get FAF imaging twice a year or Q6 months if I'm able to. But the interesting thing is I find that near-infrared reflectance imaging or that on FOS imaging that comes with the OCT is also a very critical part in GA management in my practice. I think it's an easy picture to take. It doesn't require a bright flash. It can be taken in an undilated state. And it provides a pretty good highlight and outline of a GA lesion. So I find myself using autofluorescence twice a year, if possible. But the OCT seems to be the mainstay in my practice, partly because the near-infrared image can be correlated with the cross-sectional view, but also because we know that GA treatments can actually slightly increase the risk of neovascular disease, in which case OCT is really the gold standard.
Diana Do: Thank you so much for sharing your expertise, Deepak. I really enjoyed learning from you and I'm sure all of our viewers have too.
Dr. Sambhara: Thank you for having me.
