What It Means to Be a Glaucoma Suspect and What Happens Next

What It Means to Be Labeled a Glaucoma Suspect

Interviewer: So, after your last eye doctor appointment, you were told that you're a glaucoma suspect. It can feel kind of like a half diagnosis, just enough to worry, but not enough to maybe know what to do next. So today we're going to unpack what that label means, how your doctors decide who needs treatment versus monitoring, and what you can do to protect your vision for the long haul.

Today, I'm here with Dr. Rachel Simpson, an ophthalmologist, glaucoma specialist, and the vice chair of education at the University of Utah's John A. Moran Eye Center, where she specializes in the medical and surgical treatment of glaucoma.

So, Dr. Simpson, let's start right there. The term itself, glaucoma suspect, when I hear suspect, I'm thinking of a murder mystery. I'm thinking of the guy who did it. What is this terminology, and why is it used?

Dr. Simpson: It's funny, I'm glad you say that because I do kind of joke about that terminology with my patients. I'll tell them, "You're suspected of glaucoma, but don't worry. You haven't been convicted of glaucoma yet."

So we'd like to think in modern medicine, today's day and age, that we are very good, we are these diagnosticians that can pinpoint easily, "This is glaucoma. This is not glaucoma. You have it, and you definitively don't have it and will never get it." And unfortunately, that is just not reality.

Glaucoma Exists on a Spectrum

Glaucoma is a disease spectrum. And like most diseases that are spectrums . . . Think about diabetes. We do the same thing with diabetes. There's this kind of gray area where we call you a borderline diabetic. There are certainly very definitive diagnoses of diabetes where things are very glaringly obvious. But for some people, you're kind of in that gray area where your sugars are a little bit high, but maybe not quite so high that we'd call you diabetic. The same is true with glaucoma.

There are a whole number of diagnostic criteria that you have to meet in order to truly be diagnosed with glaucoma. And oftentimes we'll find patients where, say, they have one or maybe two of those diagnostic criteria, but they don't quite check every box. And so those are the patients that we call glaucoma suspects.

We can stratify within that. We can say, "You are a low-risk glaucoma suspect," or, "You are a high-risk glaucoma suspect," based on a number of risk factors that we are talking about in clinic. But it is kind of this weird gray area diagnosis that I know is a little bit unsatisfactory for both me as the doctor and also for the patient.

Risk Factors That Increase the Chance of Glaucoma

Interviewer: Gotcha. So I guess if they are determined to be a glaucoma suspect, what can they expect for treatment or monitoring moving forward? And what, as a doctor, do you do with a patient who is this type of suspect?

Dr. Simpson: So first, I'll explain to them when I see them the things that I see on their exam that make me call them a suspect. 

Optic Nerve Appearance

I'll tell them, "When I look at your optic nerve, the central part of your optic nerve, which is called the optic nerve cup, looks larger than it does in the average person." And sometimes that can just mean you have a larger-than-average optic nerve excavation, and that's all it means. But sometimes it means it's larger than average because you're starting to lose thickness from the inside out, which is what glaucoma does.

I don't have a great way of knowing whether this is just how your optic nerve looks, or this is the very early start of glaucoma. So we'll take some pictures in clinic. We'll get baseline optic nerve thickness exams, and that will sometimes help us delineate, "Is this optic nerve looking this way because it's getting thin," which we'll frequently be able to see on the pictures that we take, "or is this optic nerve healthy?" And that will give us a snapshot in time.

Right now, say you come in, and your optic nerve looks suspicious, but the scan that we do tells us the thickness is normal. Well, that's one reassuring factor. You have suspicious nerves, but your optic nerves are actually normal thickness. So that's good.

Family History

And then I ask you about your family history. Does glaucoma run in your family? There is a genetic component to glaucoma. So if you have a strong family history of glaucoma, you're at significantly higher risk of developing it later.

If this person then says, "Yes. You know what? My mother and three of my sisters and my maternal grandmother all have glaucoma, but not only that, they have severe glaucoma, and one of them has gone blind," then that to me will elevate your risk of developing glaucoma compared to someone who's like, "Nope, nobody in my family has glaucoma." So we take that into account as well.

Eye Pressure

And then the other thing we look at is eye pressure. Where is your eye pressure? Is it measuring normal? Is it measuring slightly high?

Age

And then the last thing is age. Glaucoma is a disease that is very strongly related to aging. The older you get, the more likely you are to develop it.

So one thing that's really hard about being called a glaucoma suspect is I will frequently be able to tell people, "Right now, at this snapshot in time, you don't have glaucoma. But what I'm not able to do is tell you 5, 10, 20 years from now if that same thing won't be true."

Additional Testing and Monitoring

Anybody who gets called a glaucoma suspect has to undergo just a little bit more testing. How much more testing depends on whether or not we've decided you're a low-risk glaucoma suspect or a high-risk glaucoma suspect.

My low-risk glaucoma suspects, I just see them once a year, and I do a couple of extra tests. I do optic nerve thickness testing every year, I check their pressure, and I'll do a visual field every two to three years.

My high-risk glaucoma suspects, those patients that I really think are probably on the borderline of developing glaucoma, I might see them every four months, which is how often I see my stable glaucoma patients. And we're still doing all those same testing. We're testing pressure, we're doing visual fields, we're doing optic nerve thickness maps every visit, every four months.

So you will definitely get told that you'll need additional follow-up or a little bit more follow-up than what you would get at just your average optometry appointment.

Interviewer: Gotcha. That was one of the things that I kind of came across in my patient research, was that they're like, "Why am I doing so many tests?" And it makes sense. If we're not 100% sure glaucoma or no, we need all of those individual things, and a monitoring plan sounds like something that can help catch it early.

Dr. Simpson: Yeah, exactly. And the testing with glaucoma is something that patients notoriously don't love. Not because it's painful, but just because it's time-consuming and a little bit frustrating, especially the visual field test. People like to do well on tests, and that's a test where you kind of don't know for certain if you've done well, and you don't get that instant feedback of, "Yeah, you aced that test."

So people sometimes can get frustrated with the amount of testing that we do, but I find that if I explain it to patients clearly why we're doing all this testing . . . Glaucoma is a disease of progression. And if all I have is one data point in time, I can't assess for progression. The more data points spread over a timeline that I have, the easier time I have assessing for progression.

So the more data points I have that show you are stable, and there is nothing changing, the more confident I am telling you your risk of glaucoma is very low. And if all of a sudden, I have data points that start to show subtle changes where I can see, "Wow, that optic nerve thickness was 105 last time, and today it's 102," and then the next time you come in, it's 97, that to me is like, "We need to reassess. You actually might be starting to develop glaucoma." And so, that is why all that testing is so critically important.

When a Glaucoma Suspect May Need Treatment

Interviewer: Now, when does a suspect become something to actually treat? If we treat glaucoma as early as possible, at what point in the monitoring program do we decide, "Yeah, it's time to maybe try out a laser or drops"?

Dr. Simpson: It's a great question. So the textbook official diagnosis is that you have to have visual field changes. That diagnostic criteria is pretty antiquated. It was established before we had the ability to do these optic nerve thickness maps that we do with OCT.

So OCT is able to detect optic nerve thinning now, long before you have any visual field changes, which is great. It means that we can kind of start to see these subtle changes in thickness that allow us to intervene before you've lost any vision.

Balancing Monitoring vs. Early Treatment

And so for me, that's kind of one major area where we talk about starting treatment. You haven't lost any vision yet, but I can start to see some very subtle optic nerve changes. That's where we would start treatment.

The other thing is eye pressure. So sometimes I'll have patients who constantly have slightly higher than average eye pressures, but every other part of their test is normal. Their optic nerve looks good. Their visual field looks good. I'm okay with them having slightly higher than average pressures.

But as that pressure starts to creep higher and higher, we know that anything above a pressure of 28 or 30, even if all the other testing is right now showing stability, dramatically increases the risk you'll develop glaucoma over time.

So we'll frequently intervene if we see the eye pressure starting to go up, even if we don't see damage to the optic nerve happening yet. And so those are kind of the two big areas where it's very easy for us to intervene.

Then there are some patients who just prefer a more cautious approach. So if you're a high-risk glaucoma suspect, and say your pressures are borderline elevated, I might talk to you and say, "You are in a gray zone where I can't definitively right now tell you that you have glaucoma, but I also can't definitively tell you right now that you don't. So we can approach this one of two ways."

We can approach this with the wait-and-see, and I bring you back frequently, and we do this testing, and we only start treatment when we're certain. Knowing that with this approach, there is a slight risk that you might have some slight damage to the optic nerve in between our follow-up intervals. That damage will be mild, and it won't result in any vision changes, but there is a risk.

Or we can start you on treatment now, knowing that ultimately you might not actually develop glaucoma, and you will have had a treatment that is, in retrospect, unnecessary.

It all has to do with your comfort and where on that kind of risk-reward stratification you feel like you want to be.

I do have patients who say, "I don't want any treatment unless you're 100% certain." And I have patients who are completely the opposite, who are like, "I don't want to risk anything. Please start me on treatment."

What Patients Can Do to Protect Their Vision

Interviewer: So I did want to ask one last time, if someone is listening right now and, yes, they've heard all the steps and definitions, etc., and they might still be kind of anxious being labeled a glaucoma suspect, whether it's them or one of their loved ones, how do you kind of reassure them that maybe we can flatten that line, maybe we can keep glaucoma from becoming something more serious?

Dr. Simpson: That is one of the questions I frequently get, and I like to offer reassurance first. The thing patients often ask is, "Well, what can I do? What can I, as the patient, do? What kinds of things can I personally control that will let me determine whether or not I get glaucoma?"

We're so used to this in medicine right now, especially again with things like diabetes and blood pressure. If you change your diet and you start exercising, as a patient, you have a lot of control over your disease. Unfortunately, this is not true with glaucoma.

So I tell them the double-edged sword of glaucoma is that it is very independent of you and things you are doing or things that you are not doing. So you don't have to feel guilty that you didn't go for a run this morning, but also it means that if you do these lifestyle changes, it probably isn't going to change the trajectory of your disease very much. I tell them my job is to make sure that we're catching the disease as early as possible, before you lose any vision.

Early Detection Can Preserve Vision

I kind of go back to that idea that we now have this ability to detect subtle changes in the optic nerve long before you lose vision, and that you are here in the very early stages. If this is glaucoma, we've caught it so early that we can't detect any damage. My job is to make sure that that stays the case. And their follow-up is going to be important in making sure that that continues to be the case.

So again, just making sure that you have a doctor that you can trust who's explaining all of these things and that you're able to build that rapport with. And then have those frequent check-ins with them once or twice a year, making sure that you guys are talking and checking in on all of those risk factors.