Adopting Angle-Based MIGS Procedures

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6 min read
Dr. Sheybani reviews how to adopt angle-based minimally invasive glaucoma surgery (MIGS) procedures and their value to comprehensive ophthalmologists.
In this Interventional Mindset video, glaucoma specialists Arsham Sheybani, MD, and Nathan Radcliffe, MD, discuss the value of comprehensive ophthalmologists adopting angle-based minimally invasive glaucoma surgery (MIGS) procedures.

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The role of comprehensive ophthalmology

Given the disease burden in the population, there is a noted paucity of glaucoma specialists. One viable solution to ensure glaucoma patients receive the most effective therapies in a timely manner is to educate and engage comprehensive ophthalmologists in MIGS. This strategy lies at the core of having an interventional mindset.
Taking into account that many cataract patients may concurrently be treated for glaucoma, it is only logical that these physicians should be trained to perform MIGS. As a residency director, Dr. Sheybani incorporates MIGS into his comprehensive ophthalmology curriculum.
As a range of MIGS can be successfully performed in conjunction with intraocular lens (IOL) implantation at the time of cataract surgery, eligible patients should be informed of this possibility during their consultation. Dr. Sheybani goes as far as to suggest that MIGS should be included in every cataract surgeon's informed consent, thereby introducing the discussion of reducing the intraocular pressure (IOP)-lowering drop burden through a minimally invasive procedure to every suitable candidate.

Proof from the pandemic

The integral role that optometrists, comprehensive ophthalmologists, and even primary care physicians play in preventing glaucoma progression became even more evident to both Dr. Sheybani and Dr. Radcliffe during the pandemic. Dr. Sheybani noted at his clinic the number of emergent surgeries dropped significantly because, without access to these frontline providers, patients were not being screened and diagnosed.
Therefore, individuals were not aware they were suffering from threateningly high IOP. Dr. Sheybani noted examples of patients whose charting showed 20/25 pre-pandemic but deteriorated to hand-motion (HM)/light perception (LP) by their next post-pandemic visit.

Benefits of MIGS at the time of cataract surgery

There are three key benefits to performing MIGS at the time of cataract surgery: decreasing drop burden, enhancing vision, and eliminating the need for future invasive surgery.

1. Decreased drop burden

The holding power of the drop reduction in MIGS patients is typically better than in those who only undergo a straight phaco lens surgery.
An initial 2-iStent study conducted by Dr. Sheybani through the VA Medical Center-John Cochran Division in St. Louis demonstrated that patients who received an iStent (Glaukos) at the time of cataract surgery had a significant reduction in the number of drops necessary following surgery, as opposed to the control group who did not receive the stent.
He also noted no increase in complications with the MIGS group.1 It follows that by lowering the drug burden, the cost is also lowered for all involved.

2. Enhanced vision

In his own research, Dr. Radcliffe has found visual acuity to often be better in the stent group than in the control group, with 4 to 5% more patients achieving 20/20 uncorrected vision post-operatively.

3. Eliminating future surgery

Patients who undergo a MIGS procedure at the time of cataract surgery are less likely to require a secondary surgical intervention. According to Dr. Radcliffe, Hydrus 4-year data illustrated that people who received the Hydrus microstent (Alcon) were less likely to require a future incisional surgery than those who underwent phaco alone.2
These factors and the current clinical data serve as evidence as to why all ocular surgeons should investigate and integrate trabecular meshwork procedures.

Getting started with MIGS

Prior to performing MIGS, it is imperative to become comfortable with visualizing and measuring the chamber angle through gonioscopy. Dr. Sheybani recommends utilizing a surgical gonioprism, such as Katena's single-use version. Once you become comfortable with identifying the chamber, you are one step closer to incorporating MIGS into your cataract surgeries.
As a next step, consider adding goniotomy as a means to reduce IOP to your armamentarium. In addition, a non-penetrating procedure, such as canaloplasty, which entails cannulation of the Schlemm’s canal using a microcatheter, can serve as a segue to more complex MIGS procedures, such as the iStent or Hydrus microstent.
For surgeons who are still nervous about the proper placement of these devices, Dr. Sheybani suggests creating a visual guide by staining the trabecular meshwork with Trypan blue dye. In his practice, even for some of the standalone gap procedures, Trypan is injected pre-operatively to ensure accuracy and consistency.

In closing

In relation to glaucoma, ophthalmologists share one common goal—to slow progression or even halt vision loss. Dr. Sheybani reiterated that, as a general rule, glaucoma specialists are not territorial, and both surgeons concur that when vision is at stake, intervention should occur at the first qualified point of care.
With this discussion, they hope to energize doctors to take an interventional approach to glaucoma. One clear way for comprehensive ophthalmologists who are currently performing cataract procedures to elevate their level of care is by delving into combining IOL surgery with MIGS with appropriate surgical candidates.
  1. Ahmed IIK, Sheybani A, De Francesco T, et al. Long-Term Endothelial Safety Profile With iStent Inject in Patients With Open-Angle Glaucoma. Am J Ophthalmol. 2023;252:17-25. doi: 10.1016/j.ajo.2023.02.014.
  2. Ahmed IIK, De Francesco T, Rhee D, McCabe C, Flowers B, Gazzard G, Samuelson TW, Singh K; HORIZON Investigators. Long-term Outcomes from the HORIZON Randomized Trial for a Schlemm's Canal Microstent in Combination Cataract and Glaucoma Surgery. Ophthalmology. 2022;129(7):742-751. doi: 10.1016/j.ophtha.2022.02.021.
Arsham Sheybani, MD
About Arsham Sheybani, MD

Arsham Sheybani, MD is an associate professor of ophthalmology and visual sciences. His areas of specialty include glaucoma and surgical management of the anterior chamber.

Arsham Sheybani, MD
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