Improving AMD Outcomes with the AdaptDx
Jeffry Gerson, OD, FAAO
Dr. Gerson discusses the AdaptDx® by MacuLogix® and how he is using it in his practice to uncover previously undetected cases of age-related macular degeneration.
I’m really excited to be able to be here with you and talk about something that I’m really passionate about. Something that I think not only do I now have the passion for but I have better tools to really fuel my passion. I’m really excited to be here and talk to you about MacuLogix and their instrument, the AdaptDx.
Familiar Case of Very Small Drusen
Before I start talking about AdaptDx, I want to share a case with you. This is something that I’ve become extremely familiar with in my practice. It’s a patient that comes in like this: a 65 year old female, 20/20 vision, no family history of AMD, nonsmoker.
I’m not really worried about this person. You take a look inside their eye, you see the picture here and you really don’t see much. But there’s an area where there might be a couple of very very small little drusen. Or some other very very minimal change that usually we would look at and say “no big deal”, we would not be very concerned, we wouldn’t worry about that.
We’ll say this person has very subtle drusen. So you do an OCT as we oftentimes do and it’s completely unremarkable. Even if you’ve got the right slice and you’re going through that area, you don’t see anything.
But now what I do in my practice is dark adaptation testing. What I’ve been finding out, and I’ll share with you some really to me surprising statistics of my own, is a lot of these people have abnormal dark adaptation. What that means is this person has macular degeneration. And so now we have a diagnosis of subclinical AMD.
Dark Adaptation Testing and Subclinical AMD
We’ve heard of things like pre-diabetes or we treat pre-parametric glaucoma. But do we think about subclinical macular degeneration? I would argue that most of us probably don’t because until now we didn’t have a way to find it. It was something you could make up a word for but there was nothing you can do about it. That’s why I’m really excited about this.
Optometrists Are in the Driver’s seat: Identify AMD at Subclinical Stage
Macular degeneration is a major threat to your patients’ vision. What I would contend to you is that we’re in the driver’s seat, not the retina specialist that’s doing the antiVEGF injections. Once patients get to the retina specialist, it’s already not going to be very good ending. When we see people before they even have clinical signs of macular degeneration, and we can identify it, those are the people that will ultimately do much better. And those are the people that we have sitting in our offices.
Prevalence of AMD: Glaucoma Pales in Comparison to Macular Degeneration
What we need to realize is how many people there are with macular degeneration. If you add up patients with diabetic retinopathy plus patients with glaucoma, it equals less than the number of people with macular degeneration. How many of you have a perimeter and OCT so that you can find glaucoma early? Well, the number of people with glaucoma pales in comparison to the people with macular degeneration. Shouldn’t we want to find macular degeneration as early as we try to find glaucoma? You find glaucoma early, put someone on a drop, you try to prevent progression. I would contend we need to be thinking the exact same way when it comes to macular degeneration. Treatment for macular degeneration should start with us and with what we do, not once someone has wet AMD and they need injections.
As people get older, there is a higher percentage of patients with macular degeneration. And I would argue that these numbers are awfully conservative; that more than 1 out of 8 people over the age of 60 have age-related macular degeneration. I’ll share with you the statistics from my practice.
We are Not Finding AMD Early Enough
That’s more than 1 out of 8 that we need to find and we need to do something about. When you think about what you do about macular degeneration, you think “What does a retina specialist do? How do they treat wet AMD?” I’m not so concerned about that. I want to know what we do before somebody needs a retina specialist.
There is a startling statistic that’s saying that by the time someone needs an injection, by the time someone develops wet AMD, almost 80% of the time their vision is already worse than 20/50 and 40% of the times, they are legally blind. They’re legally blind at diagnosis which means we’re not finding it early enough.
The reason we’re not finding it early enough is we’re not using tests that are sensitive and specific to find macular degeneration.
Identify AMD earlier so that we can follow these patients more closely and start implementing measures like nutrition, lifestyle, and other things that we can do for our patients to be preventative of them ending up ever needing treatment in the first place. And if they do need treatment, we’ll find them earlier because we’re already following them more closely.
What did AREDS and AREDS2 taught us is that we can decrease the progression to wet AMD or vision loss by about 25 to 30 % with the right supplement. That means that two thirds of people that were going get worse, they will get worse. If you let them get to that stage, that intermediate or late stage of dry AMD, majority of them that are going to get worse are already going to get worse.
What I would tell you is we need to identify AMD patients earlier and prevent vision loss.
We know that anti-VEGF injections can create some stability. But what the studies are now saying is [that this stability is only] for five to seven years and after that patients get worse. What stability means is from their initial VA when they need treatment. If we can identify AMD earlier and start treatment earlier, patients start out with good vision and they’ll end up with a better vision.
I keep emphasizing prevention. The only way we can prevent vision loss is if we know in whom we need to prevent it.
It’s in Our Hands to Help Patients Have Better Results
“Many AMD patients are arriving at our practice with unnecessary vision loss. Ideally these patients would see their primary eye physician and be diagnosed earlier.” David Brown, MD, FACS (Retina Consultants of Houston).
This is a quote by Dr. Brown, a retina specialist in Houston, who is well-known in ophthalmology circles and is involved in most of the different retina clinical trials. He says that many AMD patients are arriving at their practice with unnecessary vision loss and that ideally these patients would see their primary eye physician and be diagnosed earlier. That’s us! Patients need to see us and be diagnosed earlier. And by the time they get to a retina specialist not have as bad a vision. They don’t like creating bad results
It’s in our hands to really help patients have better results.
AdaptDx Measures Dark Adaptation and Identifies AMD with 90% Accuracy
The instrument that I use in my practice is AdaptDx. It is a very simple objective tool to measure dark adaptation that functionally correlates with macular dystrophies and macular degeneration. What’s really impressive is that this instrument is over 90 % sensitive and over 90 % specific in identifying macular degeneration. It finds it when it’s there and it doesn’t find it when it’s not there.
Find AMD Before Clinical Signs Appear
From different trials and papers, we know that AdaptDx will find macular degeneration in many cases at least three years before you would actually see any clinical signs of the disease. Do you want to wait to diagnose glaucoma until someone has a fixation threatening nasal step? No, you want to find it earlier? We should be thinking the same way about macular degeneration. Let’s find it in its earliest stage so that we can do something about it and prevent the bad outcomes.
AdaptDx: Rapid versus Extended Test
AdaptDx has two different testing protocols:
- The first is a rapid test. The way I think of that is kind of like a screening. If somebody dark adapts within the first 6.5 minutes, that’s normal. If it takes longer than 6.5 minutes, we know that’s abnormal and indicative of that person having macular degeneration. It is like doing a screening visual field: You do screening visual field. Either it’s normal or we have them come back into a full threshold visual field. If the AdaptDx rapid test is abnormal, my patients come back to do extended test.
- The extended test can take up to 20 minutes depending on the severity of their macular degeneration. The more severe the macular degeneration, the longer it’ll take that person to adapt to darkness. You can actually gauge progression over time to see if someone’s macular degeneration is getting worse and having more of an effect on their vision.
Diagnostic Sensitivity and Specificity of Dark Adaptometry
This was one of the papers that was published. It looked at about 125 people with AMD and about 20 without. This is how the numbers were come up for sensitivity and specificity. If you identify someone that has macular change on photography and then run the AdaptDx test, 90% of the time the dark adaptation will be abnormal. If you take people that are normal clinically and then look at them in dark adaptation, this says that 90% of the time it’ll identify them as normal as well. AdaptDx is very sensitive and very specific for any test. I think that’s something that’s really important.
Ophthalmic Guidelines on AMD: Dark Adaptation One of First Signs
We as optometrists sometimes thing “That sounds great, Jeff, but what about our colleagues in ophthalmology?” That’s where we’re ultimately going to be referring patients. What do ophthalmologists think of this? Take a look at these guidelines from American Academy of Ophthalmology.
American Academy of Ophthalmology. “Preferred Practice Pattern for AMD.” (2015)
The AAO guidelines say that one of the first symptoms of macular degeneration that ophthalmologist or eye care providers should be looking for is difficulties in dark adaptation. In their guidelines, the standards that they create, they are specifically calling out dark adaptation as something that is important for identifying macular degeneration. This is not just something that we optometrists should believe in, but it’s something that ophthalmologists clearly believe in as well.
Risk factor versus Symptom of AMD
One thing I want very clear about is abnormal dark adaptation is not a risk factor for macular degeneration. Genetic testing and macular pigment optical density are both risk factors that do not say yes or no. AdaptDx is a test that says yes or no; it absolutely identifies macular degeneration. Impaired dark adaptation is not a risk factor. It is the earliest manifestation of the disease and I think that’s a really important distinction to realize. We’re not saying “Maybe it’ll happen.” If someone has abnormal dark adaptation, it has happened. They have macular degeneration.
Dark Adaptation Testing is Easy to Administer
You don’t need any prior dark adaptation, you don’t need to sit in a room for a while before you do the test. Patients do not need to be dilated. It’s just as easy as doing a visual field test. It’s completely automated and very easy for your technician or staff or even you to be able to run it. AdaptDx gives an objective output, it gives you RI (Rod Intercept) which will tell you whether the patient has normal or abnormal dark adaptation. It is a reimbursable test. It’s about the same footprint as a visual field. It reimburses about the same and often times it takes about the same amount of time as doing a visual field.
There are ICD-10 codes that allow for reimbursement of the AdaptDx, the most important being ‘acquired night blindness.’ It’s pretty easy to ask a patient “Do you have problems driving at night? Do you have problems when it’s nighttime?” If so, then you have acquired night blindness and you can bill the AdaptDx test medically.
AdaptDx is Good for Your Practice and Good for Your Patients
Once you’ve identified that someone has macular degeneration that brings along a whole other host of things that we need to do for them. It’s no longer just a once-a-year patient that we do our routine exam. There’s all sorts of other tests that we’re going to want to be doing. There maybe even be optical products or other things that we need to recommend to these people because we now know they have macular degeneration.
This is good for your practice and for your patients, because we can detect something earlier and intervene earlier.
I would imagine that most of you have some experience and believe in nutritional supplementation. These are people that absolutely need nutritional supplementation because they have macular degeneration. Few people would argue that patients with AMD don’t need supplements, most of us would say they do. Now we know these people need supplements and we’re able to help preserve their vision and their overall quality of life.
It is good for your practice because instead of someone coming in once a year for a routine exam, now they’re in your office maybe two or three times a year and you’re doing other tests that we should be doing. All of a sudden, this isn’t an $80 or $100 a year patient. These patients are worth up to around $600 a year to your practice. They are worth about 7x as much to your practice as they would have been had you not identified that they have early macular degeneration.
Gary Kirman is an OD in Pennsylvania that’s been using AdaptDx for a couple years. He’s gone back and looked at his metrics: His average patient generates $80 every 18 months. Patients he’s able to identify as having macular degeneration now generate about $650 a year. This is a huge boost to your revenue. And the cool thing about it is it’s a boost to your revenue because you’re doing the right thing. You’re identifying a disease process and you’re doing the right thing for your patients. And usually when you do things like that you prosper.
At the beginning, I mentioned my real-life experience with AdaptDx. What I’ve started doing is I have a series of 40 consecutive patients over age 60 with no clinical findings, meaning I do my routine exam, they’re dilated, everything looks completely normal. I then do an OCT and dark adaptation test with AdaptDx. So far 12 of the 40 have had abnormal dark adaptation. Twelve out of those 40 patients that I thought were completely normal turn out they have subclinical macular degeneration. As I said, I’m doing OCT in all these patients and none of them have had any drusen on OCT. When I look at the OCT metrics, at age based norms for overall retinal thickness, it’s all normal. There’s no other tests that I have or I could be doing that would be telling me these patients definitively have macular degeneration. For me, AdaptDx has completely changed the way that I’m looking at these patients because now I know who has macular degeneration. Before I was assuming many people didn’t so it’s really thrust me into doing things quite a bit differently.
Questions from the audience:
If someone has abnormal dark adaptation, does it definitely mean they have AMD?
If someone has abnormal dark adaptations that means they definitively have AMD. There are several other things that can cause abnormal dark annotation: some sort of macular dystrophy, retinal dystrophy, or a generalized vitamin A deficiency. That’s about it. Unless you have one of those two things, it is age-related macular degeneration.
Using supplementation, have you seen reverse in dark adaptation?
Have I seen a reverse? This is fairly new and I’ve been doing this for about three months. Have me back in a year and I’ll tell you what I’m seeing. These are all people that I’m now starting on supplementation. I’m an avid advocate for supplementation. That being said, I don’t think everybody needs supplementation. These patients do. You’d be hard-pressed to make a good argument to say “These people are probably going to do fine. So you don’t really need to do anything.”
How does MPOD correlate with Dark Adaptation?
What I’ve seen from MPOD is it does not correlate with dark adaptation. I’ve had some people that have pretty good MPOD that have poor dark adaptation and then some people that have the opposite. Again, MPOD is just a risk factor. We’ve all have had patients with AMD with pretty good MPOD or a really bad MPOD that don’t develop AMD. That is because MPOD is a risk factor versus dark adaptation is a definitive diagnostic marker.
Do you test both eyes?
For the series that I’ve created I’m just testing one eye. Literature says you only need to test one eye; the only reason to test both eyes is if you’re doing the extended test and you’re staging and you want a very critically look at each eye to see how each eye is responding. But literature will tell you that if you test one eye and it’s abnormal that you don’t need to test the other eye.
Why do AMD patients have abnormal dark adaptation?
Basically what’s happening is when you start to develop drusen that’s not the earliest change in macular degeneration. You start to get basal laminar and linear deposits that basically clog up Bruch’s membrane. The reason you have an abnormal dark adaptation is because you have a deficiency in vitamin A transport. These deposits are creating wall, this cement, along the Bruch’s membrane and vitamin A is no longer allowed to get through. It creates localized vitamin A deficiency which is what creates the change in dark adaptation.
Are cells dying?
Dark adaptation doesn’t tell you cells are dying, it tells you that the vitamin A is not getting through.
Do retinitis pigmentosa patients have abnormal dark adaptation?
I said that there are some dystrophies and degenerations or retinitis pigmentosa. I have got about a half a dozen patients that I see with with RP and when I first got the AdaptDx, I wanted to satisfy my intellectual curiosity, I wanted to see how these people do. And what I very quickly realized is they do very poorly. My tech hates when I have RP patients come in because I say “Let’s test this person, let’s just see.” And she’s like “Doc, don’t you already know the answer?” I do but I had to show myself. So, yes, patients with retinitis pigmentosa have abnormal dark adaptation.
Am I missing AMD if I’m only doing AdaptDx testing on one eye?
You’re making my case even better than I would have made in my case. Because now you’re suggesting more than 30% of my patients that I thought didn’t have AMD might. For this series I’m not testing both eyes. I am basing that on literature. You’re right, there’ll be some, there may be one or two that I will have missed. But the whole idea of a screening test is something that’s quick and easy. For my sake as a private practitioner and because I know the science, I’m able to easily rationalize only testing one eye. If the one eye has normal dark adaptation, I don’t need to do the other and vice versa. If I have one eye abnormal then there’s certainly no reason to check the other eye.
These are all great questions. There are the questions I myself had before I started using the AdaptDx. I’m not someone that you can just come to and tell “Hey, this this works. It’s great, use it.” I have to read about it, I have to be confident, I need to make sure. Hesitantly, I decided to try this based on science. And now I’m pretty enthusiastic about dark adaptation and about AdaptDx. And it is because I’ve shown myself how much AMD I can find that I would have otherwise missed.
Are the results confounded by cataracts?
No, they aren’t.
- Prevalence of AMD is higher than diabetic retinopathy and glaucoma together. We need to realize how important this is from a big picture.
- Proactive detection and management of AMD is in the hands of optometrists.
- AdaptDx allows us to find AMD early, manage it and really help our patients preserve their vision and, more importantly, preserve their overall quality of life.