A new set of guidelines for implementing interventional glaucoma

As the population of patients with glaucoma increases, interventional glaucoma strategies grow in popularity. Faced with a glut of data, technological advances and pharmaceutical revolutions, it can be challenging to determine how to best put interventional strategies into practice. A group of glaucoma specialists, general ophthalmologists and high-volume cataract surgeons may have decoded the mystery—or at least provided clinicians with a place to start.

Christine Funke, MD, is a glaucoma specialist at Barnet Dulaney Perkins Eye Center in Phoenix, Arizona, and was part of the consensus group that met in late 2024 to develop an interventional glaucoma protocol. In conversation with Ophthalmology Times Europe, she illuminated key takeaways for general ophthalmologists and specialists.

Hattie Hayes: Can you describe the stages of glaucoma as they’ve been outlined in this consensus?

Christine Funke, MD: When we started talking about the consensus, before we got into the stages, it was important that we established some rules. We decided to talk about patients as if they were coming into a clinic for the first time, naive of treatment, naive of medicine. From there, eventually, it boiled down into looking at patients based on four general categories: ocular hypertensive, mild, moderate and severe glaucoma.

Hypertensive patients are those who just have high eye pressure without disease or damage. Mild glaucoma is characterised by damage, but no visual field (VF) loss. Moderate glaucoma includes visual field loss within one hemifield, but not within the central 5 degrees. Finally, severe glaucoma, the last category, has more than one hemifield of VF loss or loss within the central [10 degrees].

But when we started to talk about the actual protocol, we looked at all the minutiae...associated with each patient’s disease. And it was interesting, because as we started to look at all these little subcategories that we thought were very important, we might say, “Oh well, if there’s pseudoexfoliation, do this,” or “If there’s pigment dispersion, try that.” We started to realise that, broadly, it didn’t matter, and that, broadly, in an ideal setting—for that patient walking in, treatment-naive—this is the framework we would like to follow. That’s how we got to find these four different categories. We thought initially that we would treat them a little differently, depending on where they were, stage-wise. But that shifted the more that we talked about it. Except for cases of severe glaucoma, we found that we liked a similar framework for each patient.

I’ve been hearing calls for a protocol from general ophthalmologists, as well as glaucoma specialists, for a very long time. A lot of people didn’t believe that a consensus could be formed, because glaucoma can be very nuanced. Our working group was mostly glaucoma specialists, as well a high-volume cataract surgeon and a general ophthalmologist. I think that is important because the majority of people treating glaucoma are general ophthalmologists. Especially when we’re talking about young glaucoma, mild glaucoma, moderate glaucoma and early-stage treatment, those are interventionally minded general ophthalmologists.

FIGURE. The consensus group developed this stage-matched protocol for interventional treatments.

HH: You delineated between ocular hypertension and glaucoma with visual field loss. What is the importance of obtaining a differential diagnosis between ocular hypertension and early-stage glaucoma?

CF: As specialists, we have become better and better at detecting disease earlier and earlier. The definitions of glaucoma have shifted because of that change in our armamentarium of finding disease. We used to not be able to really know if there was disease or not, unless we were looking at the nerve, and then we had to do very rudimentary perimetry. Then started [looking] into optical coherence tomography and ganglion cell analysis. So we’ve become more granular, in being able to look earlier and detect earlier.

Patients with ocular hypertension are a category that’s always been in my mind. We know that some will progress, but not everyone will progress. We’ve had studies to tell us the rate of progression for the majority of people with just ocular hypertension. So pure ocular hypertension, I still think, is a category unto itself.

Not everyone with ocular hypertension is going to get glaucoma. And because of that, when we started to talk about the protocol, we did treat them a little differently, meaning less aggressively. And I think that’s because these are a category of patients where, for some, watching and waiting is completely appropriate. For others, where you may have risk factors that make you a little worried that they are a higher risk for progression into true glaucoma, then you may want to treat them differently.

But you have to be a little bit more gentle, right? You’re not going to jump into doing a major trabeculectomy surgery on somebody who just has high pressure without any damage.

HH: That’s so interesting. It seems like this protocol is challenging some of the misconceptions around “aggressive” intervention and how glaucoma specialists have traditionally thought about progression.

CF: Yes, I think that’s one of the things we were focusing on. When you look at the way that the protocol shifts, it goes from non-invasive procedures all the way to the most invasive, or what we would consider to be the most invasive, subconjunctival surgery. And what we’re trying to do is exactly that: we want to first work on complete tissue sparing and tissue healing. We have a better chance of healing people, of having improvement to function and structure. I think we were hoping to shatter this misconception of being “overly aggressive.” I don’t agree with that. I think, if anything, we haven’t been aggressive enough.

Hopefully we’ll start to give people that mindset of, “Oh, I want to intervene now, because I have the potential to keep them from that end stage disease.” We have so many different tools now that we didn’t have available even 10 years ago. It’s a big mindset shift. It’s a lot to ask of people, I think, but it’s also the right thing to do for patients. When we look back 10 years from now, we’re going to see the impact of interventional glaucoma. I hope to see less of the more aggressive surgeries that we’ve been trained to do for decades, because that’s all we had.

HH: Walk me through the potential interventions, as they are stage-matched to disease progression. What should clinicians be considering for each patient group?

CF: This is going to be a long answer, but I’ll keep it more high-level. When you look at this protocol, don’t think of it as rigid, OK? This is not a rigid protocol in which you have to go from A to B to C to D. Think of it as a guideline, as a framework. Sometimes patients are going to present exactly in one spot in the paradigm. But not every patient is going to fit perfectly into the guideline from start to finish.

That being said, when a treatment-naive patient with ocular hypertension is walking into the room, and you deem they need treatment for open angles, then the strategy is lasers first. And that is the case for patients with mild as well as moderate glaucoma.

We know that selective laser trabeculoplasty (SLT), based on the LiGHT trial, is a beautiful first-line treatment. There is very limited postoperative concern. Adverse effects are smaller than [when] using eye drops, so that’s a huge thing. We don’t have to worry about compliance. The rate of success is very high, even higher in those who have never had treatment before. It’s a simple procedure to have performed, and we’re not worried about patients having any negative postoperative impact on lifestyle and quality of life. I call SLT, or direct SLT (DSLT), which is the newer version, a slam dunk because, again, it’s non-invasive, completely tissue sparing and potentially tissue regenerating.

From there, again, with all these three categories, leaving out severe, the next stage would be a procedural pharmaceutical. Procedural pharmaceuticals are extremely low-risk procedures. We find that we’re reducing the worry of compliance, which is one of the most important things we’ve always talked about and which is a big barrier for glaucoma treatment. With procedural pharmaceuticals, patients experience 24-hour delivery of a medication, which is huge. We don’t have that when we’re using drops. We also hope that, at this stage, there may be some potential tissue remodelling, which we’ve seen in some early studies, based on evidence from some of the work that’s been done at Case Western [Reserve University, in Cleveland, Ohio]. There’s more benefit to having something done procedurally for a multitude of reasons.

Once you’ve left the office-based procedural discussion behind, and things are still not controlled, then we talk about minimally invasive surgery. When we looked at minimally invasive surgery, we looked at it as two different categories, the tissue-sparing category and the non–tissue-sparing category. Once you have something non–tissue-sparing—consider goniotomy—you’ve lost a lot of your ability then to go on to do other things in the angle. So, we all agreed that we would prefer to tissue spare first, to try a canaloplasty, to try stenting, because we still have options postoperatively to go back in the angle for another procedure [on] another day.

After all of that was exhausted, we decided that, for especially these categories of mild-to-moderate glaucoma, it may be more appropriate to put some medications on, even if you know it might be just [be] a bridge or a supplement for a while before going into doing filtering surgery. That’s when it becomes more challenging because we have to start asking the questions of compliance, quality of life, and other issues that go around using topical therapies, especially when you’re layering topical therapies. We weren’t under the assumption everyone...would max out before we filtered, but we felt that it was appropriate to put medications in that portion of the of the guideline, because it didn’t seem appropriate just to hop right to filtering before trying any topicals, especially for somebody who had more mild disease.

The severe glaucoma category was kind of an entire discussion unto itself. When somebody comes in and they are immediately presenting to you as severe, you’re going to feel a lot more pressure to get the IOP down significantly.

We didn’t think, for most patients with severe glaucoma, it would be appropriate to use SLT as a first-line treatment, because it takes a while for it to work and usually those patients need something that’s going to be more advanced in nature. It doesn’t mean that SLT couldn’t be used in those patients, but it just may not be the first thing you would hop to. Those patients may also need combined procedures. Sometimes you have to hop straight to filtration surgery, because you know that that’s our only option. So, again, we thought of all these things as a guideline, but this is the framework that we thought made the most sense and fit the most patients.

HH: Was there anything that you all, as a group, determined didn’t need to be part of this protocol, though it may still need to be part of the treatment conversation?

CF: We didn’t think we would get to consensus. Let’s just start there.

All of us in the room, we all do interventional glaucoma. We all believe in the interventional approach, I think that probably helped us to some degree. But everybody’s very different. Some people were more conservative. Some people were less conservative with how they wanted to treat and manage. So I think we were all surprised to eventually be able to come to a complete consensus

We kept reminding each other that we were trying to make a consensus that could fit the majority of patients comfortably. Our goal was to guide others, especially those who aren’t living and breathing glaucoma. Not everybody does glaucoma all day long. Not everyone’s in an operating room where every single patient is a glaucoma patient. It’s important for others to feel supported by the community about how we want to run glaucoma and how we want to treat our patients.

The adoption of interventional glaucoma [treatment] is a little slower than a lot of us would like. I think a lot of it is just paralysis. There are so many options. There is so much to learn. It’s scary and hard to learn something new on your own, and there was no consensus as to what to learn, and when to use those procedures.

A lot of my cataract colleagues are very interested in doing minimally invasive [glaucoma surgery] and are starting to become more interested in it. Interventional glaucoma [treatment] has continued to get talked about more and more in in the meetings and in publications. This is, as you know, a large, burgeoning volume of patients who will potentially need multiple procedures throughout their lifetime for a disease that we can’t cure.

Eventually, there may be more glaucoma procedures being done throughout the world than cataract procedures. The numbers are so staggering, there’s no way that specialists alone could ever take care of everyone. So I think the general ophthalmology group has to take up the work. Supporting general ophthalmologists, getting them on board, is very, very important.

HH: What do you hope readers take away from our discussion today? What’s the most significant lesson to be learned from this glimpse behind the scenes?

CF: This protocol is a guideline to help move forward with interventional glaucoma, with the ultimate goal of having much better quality of patient care than what we’ve had in the past. If we can all agree to a general consensus, I think long term we’re going to have much better success in terms of slowing down a progressive disease which can be detrimental to people’s lives.

For me personally, creating this protocol has forced me to remind myself how I want to practice with every single patient. On days where I don’t want to have the long conversation that I need to have, it’s forced me to have the discussion. I have to remind myself, “This patient’s never had SLT, and of course they should always have had that option.”

I think everyone can challenge themselves to think, “What would my protocol be?” Maybe it looks a little different than this. In the end, I think, for most people, it would come [down] to something very similar. My advice is to write it down, and it will help you in your daily practice to remember exactly how you want to function. With all the data that we now have around interventional glaucoma [treatment] and the positive impact it will have, I think the best takeaway is that self-homework.