Sponsored by Glaukos

The use of medications to treat glaucoma may not be going away completely yet, but their position in the treatment paradigm is changing now. Historically, drops were considered the de facto starting point for treatment-naïve patients, but that is no longer the case with the emergence of safe procedural options that are demonstrated to provide at least equivalent, but often better IOP-lowering efficacy and superior long-term control relative to pharmacologic options. If ever there was a roadblock in greater utilization of MIGS devices and procedures, it was the requirement that they be used at the time of cataract surgery.

The publication of major clinical trials in the setting of standalone MIGS is poised to change that. Emerging data provide greater confidence in establishing a new paradigm, one in which practice patterns are no longer beholden to frequently adding “one more drop” or waiting for incisional glaucoma procedures to be necessary. Instead, surgeons can consider the viability of a MIGS procedure for the millions of patients with glaucoma who are not yet eligible for cataract surgery or who have already undergone cataract surgery, whether they have failed prior procedures or not.

In a recent interview, two surgeons discussed their thoughts on standalone MIGS, considerations for patient selection, and why fellow surgeons should consider it an option early in the treatment paradigm, irrespective of the stage of glaucoma.

Why is standalone MIGS a viable alternative to drop therapy in appropriately selected patients?

Steven R. Sarkisian Jr, MD: In my practice, laser trabeculoplasty is the first-line glaucoma therapy, not eye drops, followed by sustained release glaucoma medications as second- or third-line therapy. My referral network knows my practice preference, so I regularly get patients for standalone MIGS at the appropriate time, and the appropriate time is when laser trabeculoplasty and/or one or two eye drops is not getting the patient to the target IOP range. With standalone MIGS, the stage of glaucoma is less important than the pressure and the number of medications. The benefit of standalone MIGS, or procedural pharmaceuticals for that matter, is that you remove the issue of patient compliance and adherence. When we look at all the data, only about 10% of patients exhibit perfect compliance, and maybe 40% to 60% demonstrate marginal compliance.1 But even with perfect compliance, patients still have diurnal fluctuations that are harmful to long-term eye health. So, standalone MIGS is more than a viable alternative; I really believe it’s the preference. When we have the right opportunity, we should be thinking about ways to remove the compliance question, and in doing so, eliminate the potential for fluctuations, whether that’s with a primary SLT, or even better, by directly improving the outflow with something like the iStent infinite or the iDose TR (travoprost intracameral implant) 75 mcg (Glaukos).

Arkadiy Yadgarov, MD: There are inherent flaws in topical drop therapies, predominantly adherence and compliance—patients not using their drops correctly or as often as we want them to. The reasons for that are multifactorial. Standalone MIGS is a viable alternative because drop therapy is often not good enough, as progressive glaucoma still occurs despite the use of drops in many patients. Furthermore, we now have data from major clinical trials showing lower rates of progression associated with interventional approaches when compared to medication.2,3

What patient or clinical factors do you look at to determine when a standalone MIGS might be viable?

Dr. Yadgarov: The biggest red flags are when you have a patient who's telling you that they're not using their drops as instructed, that they’re bothered by them, or have simply stopped taking them. I offer MIGS as an alternative for these patients. I especially discuss MIGS with patients who are taking their drops as prescribed yet still show disease progression. Another scenario where MIGS is a good option would be where medication has improved the eye pressure, but not low enough for that patient’s eye. We've learned from studies that the more topical medications you add, the worse the compliance and the greater the incident rates for dry eye and ocular discomfort. Instead of adding more and more topical medications, we should consider having a discussion about standalone MIGS.

The pivotal trial for iStent infinite enrolled patients with uncontrolled glaucoma.4 Are you guided by that in selecting patients in real-world practice or are there other patient types for whom a standalone iStent infinite procedure would be appropriate?

Dr. Yadgarov: I'm encouraged by the pivotal trial. It's impressive that implanting these tiny stents in the trabecular meshwork was able to do as well as it did in extremely difficult, refractory glaucoma patients, especially because invasive surgeries are many times ineffective in those types of eyes. The study has reassured me that I should at least try the iStent infinite procedure before I go on to a more invasive incisional surgery due to its safety profile. Of note, irrespective of stage, if there are signs of progressive disease in setting of eye drops and interventional treatment, whether it's mild, moderate, severe, then that's refractory glaucoma, and therefore likely good candidates for iStent infinite. You shouldn't wait on progression to a more advanced stage of disease to think of iStent infinite.

Dr. Sarkisian: I was blessed to be the first author on the pivotal trial paper, and the results positively shocked me. This was a group of patients with an average medicated IOP of 23 mm Hg, who had failed prior procedures, and the final outcome was mean IOP in the mid-teens. We’ve known for a long time that steady IOP under 18 mm Hg leads to better preservation of visual field.5 And so, I think the real take-home from the study is that iStent infinite worked, and worked very well, in patients with refractory glaucoma; but we also don’t have to wait for advanced glaucoma to start thinking about standalone MIGS. There are really two great windows of opportunity for standalone MIGS: the study shows us it is viable after a failed incisional surgery, but also before that option becomes necessary, in patients who have failed prior medical and surgical therapy. In the real world, we have to deliver a safe and effective treatment to protect patients’ vision, so that opens up numerous iStent infinite opportunities.

With standalone MIGS, are you able to think about quality-of-life outcomes or other real-world outcomes that wouldn't have been measured in the clinical trial?

Dr. Yadgarov: Absolutely. If I am able to delay or avoid a trabeculectomy or tube surgery, I am sparing patients from invasive procedures associated with a very intensive postoperative clinical course and the serious risks associated with them.6,7 If the glaucoma is extremely advanced, then you weigh the importance of IOP reduction over quality of life, in which case a trabeculectomy or tube-based procedure might be appropriate. But if they're not quite at that severity, the surgeon should attempt to treat the glaucoma with the safest and least invasive procedure first and therefore avoid the potential to significantly worsen their quality of life as would happen with traditional incisional surgeries.

Dr. Sarkisian: The patient's quality of life significantly improves when they're not reminded every day that they have a blinding illness by having to continually use their eyedrops. Their quality of life is improved when drop burden is reduced or removed by utilizing technologies such as iStent infinite.