It has been well over a decade since the US Food and Drug Administration’s approval of the iStent in 2012. Yet it is estimated that nearly half of glaucoma patients undergoing cataract surgery do not receive any concomitant glaucoma treatment, MIGS or otherwise.
I have never—not once—had a patient decline a MIGS procedure when offered at the time of cataract surgery. It seems reasonable to conclude that, in some cases, it is the surgeon who is choosing to avoid these procedures. It’s worth taking a moment to consider why this happens, and what, if anything, we can do about it.
The hardest issue to address is that some surgeons may simply not want to treat glaucoma at all. If they routinely refer cataract patients with glaucoma to colleagues, that is understandable. Otherwise, I fear that nothing short of a miracle cure with 100% safety and efficacy would be of interest to these surgeons.
Another group of surgeons who refrain from MIGS may be those who are uncomfortable with gonioscopy. We now have more than a decade of gonioscopic education behind us, and it is fair to say we have reached most of the surgeons who want to learn this skill. However, several emerging treatments may offer glaucoma care options that do not require comfort with gonioscopy. Direct selective laser trabeculoplasty (Voyager; Alcon), for example, may make laser treatment far more accessible. SpyGlass has developed an intraocular lens drug-delivery platform capable of delivering up to 3 years of bimatoprost to patients without meaningful deviation from standard cataract technique; this technology is currently in phase 3 trials. Additionally, ViaLase has developed a femtosecond laser capable of performing a true goniotomy in an automated, image-guided fashion. This approach may allow surgeons who are less comfortable with gonioscopy to perform a goniotomy either independently or at the time of cataract surgery.
There may also be surgeons who previously performed MIGS but stopped after encountering a complication—the MIGS equivalent of buyer’s remorse. Most surgeons eventually return after such an experience, but perhaps not all. These physicians may be more comfortable with drug- delivery approaches, such as the SpyGlass platform or iDose TR (Glaukos), which delivers travoprost for an extended duration without the bleeding risk associated with angle surgery. The soon-to-be-available excimer laser trabeculostomy should also offer a very favorable safety profile. Canaloplasty, particularly with second-generation instruments such as Streamline (New World Medical), is associated with a low risk of hyphema as well.
In summary, we are making meaningful progress in developing glaucoma treatments that are more adaptable for cataract surgeons who are hesitant about gonioscopy. Although some surgeons may prefer not to engage in glaucoma care at all, for those who are interested, our field is producing excellent new options—and patients stand to benefit the most.
I hope you enjoy this issue of Glaucoma Physician, where we explore the many advances that continue to improve glaucoma treatment. GP
