Every year we see more objective evidence that glaucoma should be treated with eye drops only when surgery fails, rather than the other way around. The LiGHT study, described in the cover story of this issue of OSN, is one good example of such evidence. Other studies, both in Europe and the U.S., have shown that visual field loss after trabeculectomy is similar to drops. With the growing variety of even simpler, approved MIGS procedures, the threshold for surgical intervention should arguably be even lower. As an investigator in the FDA clinical trial for the first iStent, I realized the benefit of these devices at an early stage. Upon their approval, I embraced them along with other procedures like trabeculotomy.
What we have learned is that MIGS works. I recently presented the 3-year outcomes on 96 of our own patients with the iStent classic (Glaukos). Mean reduction in IOP was nearly 20%, and 73% of patients achieved an IOP of 15 mm Hg or lower that was sustained for all 3 years.
Glaucoma specialists, too, agree that MIGS works, as evidenced by the sharp drop in U.S. trabeculectomy procedures over the past several years. A recent trend toward C-MIGS — the use of combining multiple MIGS modalities (like ECP and a stent) at the same visit to the OR — is starting to replace penetrating procedures for treatment of advanced glaucoma.
For my own less severe glaucoma patients, I prefer a staged approach to MIGS.
A goal we should target in glaucoma therapy is the elimination of drops rather than just being satisfied with what we get with a single MIGS procedure. When performing cataract surgery in a glaucoma patient, I educate the patient about their specific IOP goal to get them off drops. I explain that with cataract surgery/MIGS, we will have a two in three chance of eliminating one medication and a one in three chance of eliminating two medications. We will give the first glaucoma procedure (combined with cataract surgery) a few months to determine its effectiveness and then determine whether a second trip to the operating room is necessary to perform an additional minor glaucoma procedure, hopefully to eliminate any remaining drops.
In the first procedure, performed with cataract surgery, I select an iStent or Hydrus (Ivantis) that can only be performed in that setting and allows preservation of angle structures for possible later second surgery. These procedures rarely cause much bleeding, which can decrease the “wow effect” of premium implants that I commonly use. After their cataract surgery, most patients are happy with their results and the experience, and they have less fear of a second procedure, if needed. Now they’re in a better position to decide whether a second surgery is of interest. For that second procedure, performed 3 to 4 months after the first, I would use a stand-alone technology such as trabeculotomy with a Trabectome (NeoMedix) or Kahook Dual Blade (New World Medical), or a Sight Sciences Omni procedure. Other options could include a Xen stent (Allergan) or Trab 360 (Sight Sciences).
In performing these second procedures, we need to avoid interfering with the stents that are already in the eye, but this is fairly easy by altering incision location to give us the best approach angle.
Results so far with this staged approach to MIGS have been very positive, with patients expressing appreciation for my enthusiasm to improve their lifestyle and eliminate drops. Although my number of patients and period of follow-up are still small, the pressure-lowering effects of two MIGS procedures appear to be additive, consistent with studies of C-MIGS and multiple stents.
We never cure open-angle glaucoma, but if we can control it with simple, safe, staged procedures that eliminate topical medications, we have truly given our older patients a meaningful gift: a life with less medicine, less disease and less worry.
Disclosure: Hovanesian reports he is a consultant to Glaukos, Ivantis, Sight Sciences, Alcon and Allergan.