What The Future Holds For Microinvasive Glaucoma Surgeries (MIGS)

What The Future Holds For Microinvasive Glaucoma Surgeries (MIGS)

March 08, 2022

Minimally invasive glaucoma surgery, or MIGS, has revolutionized the glaucoma surgical spacein the past 15 years.

The high safety profile and moderateefficacy of MIGS has enabled earlier surgical intervention for glaucoma, providing safe and sight-saving care sooner.

Minimally invasive glaucoma surgeries providesafe and effective alternatives to traditional filtering glaucoma surgeries in many patients. The high safety profile of MIGS enable earlier surgical interventions, which can improve visual outcome and patients’ quality of life.

There is an abundance of evidence showing the efficacy and safety of various MIGS, with innovations continuing to advance the surgical treatment of glaucoma.

Trabecular outflow remains a mainstay for MIGS targets, with distal outflow enhancement and alternative drainage pathways showing efficacy.

Comparisons of various MIGS devices and techniques are emerging, which will enable glaucoma surgeons to better design individualized care for their patients. While no single MIGS has emerged as significantly superior to others; some MIGS may be better suited for some types of glaucoma.

Microinvasive glaucoma surgeries (MIGS) began in June 2012 with the FDA approval of the first generation iStent (Glaukos). Since then, the MIGS landscape has expanded to include trabeculotomy, viscodilation, goniotomy and another trabecular meshwork (TM) stent: Hydrus microstent (Alcon, formerly Ivantis).

Many studies have proven the efficacy and safety of MIGS procedures in patients with glaucoma. These surgeries are safe alternatives for patients with mild to moderate disease and provide quicker visual recovery than more invasive incisional glaucoma surgeries.

The HORIZON study, for example, showed that less invasive procedures such as the Hydrus microstent may spare patients from requiring incisional glaucoma surgery.

Despite the consensus that these surgeries provide extensive benefits to patients with glaucoma, TM stents are now the MIGS procedure with the lowest reimbursement.

It is imperative that surgeons are aware of the current context of revised reimbursement changes and its potential implications for the future of MIGS in the algorithm of glaucoma treatment.


Glaukos initially presented iStent to the market as a Category III “Emerging Technology” current procedural terminology (CPT) code 0191T.

The widespread use of TM stents, specifically iStent and Hydrus, led the Centers for Medicare & Medicaid Services (CMS) to revise reimbursement changes for these stents. The code was changed from Category III to Category I, and this proposal was announced to be in effect starting Jan. 1, 2022.

TM stents such as iStent and Hydrus are approved for use only in combination with cataract surgery, and as such there are two Category I CPT codes: TM stent placement with complex cataract surgery (CPT code 66989) and TM stent placement with noncomplex cataract surgery (CPT code 66991).


These coding changes led to the American Medical Association’s Relative Value Scale Update Committee (RUC) 2020 survey and recommendation, which was subsequently rejected by CMS.

The updated reimbursement for TM stent placement was outrageously reduced — reimbursement is now $34.26 more than cataract surgery alone and $3.00 more than complex cataract surgery alone. The proposed rate was a nearly 90% cut to the current rate for procedures under Category III.


This announcement stirred an uproar in the ophthalmic community. Although a reduction in the physician reimbursement code was expected, this reduction was unanimously thought to be too aggressive.

Ophthalmologists, professional societies and the industry joined together to send a united message to CMS. This fervor and enthusiasm showed how strongly and passionately people believe in these sight-saving and evolving technologies.

About 1,300 comments were submitted to CMS, which led to a revision of the guidelines with a slightly increased reimbursement for TM stent placement in the final rules for 2022.

This news was a small victory, but the marginal increase in reimbursement of stent placement with cataract surgery over cataract surgery alone was especially disappointing as trabecular bypass stents provide substantial benefits to patients compared to cataract surgery alone.

High-quality peer-reviewed publications support their efficacy and safety in addition to their role in changing the course of patients’ disease and improving their quality of life.


The process to determine the new reimbursement values has several flaws. Specifically, it does not take into consideration surgeon training required to develop this skill set.

Surgeons being able to perform these surgeries proficiently and quickly does NOT equate to these surgeries being easy, and these skill sets take time and training to develop.

The revised reimbursement does not reflect common intraoperative complications, such as bleeding, and the more involved and sometimes complex postoperative management often required.

Assessment for reimbursement should also take into consideration the relative costs of each device. This proposed reimbursement change is particularly concerning as it can make TM stents unaffordable for surgeons to perform routinely.

In addition, reduced reimbursement can throw off the risk-reimbursement ratio for surgeons. Unfortunately, this may lead to a reduction in the number of TM stents performed. This shift can stifle the recent advancements in MIGS technology, and innovation may potentially suffer.

Ultimately, we are faced with a challenge. We know this technology can be beneficial for patients, but we are limited in the number of cases we can perform as we must also ensure the survival and success of our practices.


There has been no change in reimbursement for non-stent MIGS procedures as of January 2022. Substantial evidence demonstrates the efficacy and safety of these procedures in patients with different types of glaucoma.

Additionally, these surgeries can be performed independent of cataract surgery. The KDB Glide (New World Medical), for example, which was designed for excisional goniotomy, has an average selling price that is approximately $1,000 less than a TM stent.

This difference in cost can be significant for surgeons who perform cataract surgery in an ASC. The additional cost of surgical devices may deter surgeons from this technology, and there may be a shift towards using more laser technology such as transscleral or micropulse cyclophotocoagulation (CPC) or endocyclophotocoagulation (ECP).

It is important to remember that these lasers may not provide the same IOP lowering and safety profile that stent and non-stent MIGS procedures provide. Reimbursement for goniotomy has not substantially reduced over the years, but the CPT code of 65820 may be revised by CMS in the future.

THE FUTURE Moving forward, many surgeons may shift from performing TM stents to more non-implant MIGS procedures such as goniotomy with KDB Glide and canaloplasty. The beauty of the MIGS platform is that surgeons have these other technologies available to them.

Other surgeons will continue to perform stent-based MIGS procedures given their belief in the technology, and it is in the best interest to the patient. Our first objective is to have the patient’s best interest in mind, but we as surgeons must also ensure the survival of our practices.

It may not be financially possible for surgeons to perform as many TM stents with cataract surgery as they did in the past. If the trend is toward reimbursement cuts in the future, then we must be especially aware that non-valved MIGS may face reimbursement cuts next.

If this occurs, there may certainly be a shift toward performing more laser-based technology such as micropulse CPC, transscleral CPC and ECP.

It is particularly concerning that there appears to be a trend: as certain technologies become more prevalent in surgeons’ toolbox of skills, there is a greater threat toward reimbursement cuts.

If this continues, it will lead to a continuous stifling of innovative technology as surgeons can not perform such procedures in high numbers given the altered risk-reimbursement ratio.

With this in mind, we should continue to come together and fervently advocate for these surgeries to be adequately reimbursed.

No one knows for certain how reimbursement may trend in the future, but this recent cut has showed us that it is imperative for us to have our voices heard so that the best treatment options are available to our patients in the future.