Though I am primarily a cataract and refractive surgeon, I treat a lot of patients with glaucoma. Taking an interventional approach to glaucoma therapy fits perfectly with the goal in my practice to identify technologies that allow out-patients to lower IOP and reduce medications-without a major procedure that requires a lot of perioperative and postoperative management. We are well positioned to treat glaucoma before it reaches the severity level for major surgery.
Cataract surgery alone brings down the pressure, so we cataract and refractive surgeons are accustomed to moving the needle for our patients with glaucoma, but the shift to actively treating glaucoma is a major change.
I’ve always known that about 15% of my cataract patients were on some type of glaucoma medication, and cataract surgery might help reduce the burden somewhat. Now we have the technology to bring down pressure significantly during cataract surgery, or even as a standalone procedure.
The most exciting part of this, from an interventional glaucoma perspective, is that this is an entirely different threshold for glaucoma surgery than we saw in the past. Well short of the need for trabeculectomy or tube shunt, patients can have minimally invasive, lowrisk therapies that lower pressure and reduce the burden of medication. It’s a major blow against compliance problems and disease progression. And several procedures can take place during cataract surgery, with no additional risk.
Many cataract surgeons will expand into the MIGS space because the patient base is already in our exam rooms.
Whether surgeons adopt cataract surgery-paired MIGS implants or a broader range of interventional therapies, our practices will change because we are so well positioned to meet patients’ urgent need for glaucoma therapy beyond eye drops.
Therapies patients need
Interventional glaucoma therapies have been part of my practice since 2002, when I started with endocyclophotocoagulation (ECP, Endo Optiks). Today, I use CyPass (Alcon Laboratories) or iStent (Glaukos) during cataract surgery, as well as standalone procedures such as the Kahook Dual Blade (New World Medical), Visco 360 (Sight Sciences) and XEN Gel Stent (Allergan).
I am also trained in performing trabeculectomy and tube shunt surgery, but a lot goes into managing those cases. Newer procedures have much lower risk of complications, making them suitable for the majority of patients.
While we’re already working inside the eye for cataract surgery, iStent and CyPass procedures help lower pressure and get patients off their medications. What’s more, these procedures do not add significant complexity to the management of cataract patients, nor do they close any doors to future treatments. Not surprisingly, my patients are very receptive to getting one of these MIGS devices; about 95% say “Yes.”
Standalone procedures fit into my practice as well. When patients are using drops or SLT to buy time until they can get a combined cataract-MIGS surgery, but those therapies aren’t proving effective, a standalone procedure may make sense.
For example, we use gel stents (XEN) for patients with moderate to severe pseudophakic glaucoma, with results similar to trabeculectomy without the risks. Some patients whose surgeons recommend trabeculectomy or tube shunt come to our practice because they have read about these devices, and they want to try something less invasive first. It does not affect future cataract surgery or even future MIGS procedures.
It’s nice to have a variety of interventional glaucoma approaches that we can match to different types or severities of glaucoma. For example, stents and other procedures can be combined to address different mechanisms outflow and aqueous production, at the same time or in sequential fashion.
How this changes your practice
There is no major investment required to start using interventional glaucoma therapies. Neither is there a perceptible difference in preoperative time. When patients are referred to me with both cataracts and glaucoma, I need to assess the baseline pressure to document the severity of the disease and the efficacy of current treatments.
Postoperative care for combined cataract-MIGS procedures is similar to cataract alone. Following cataract surgery, we see patients at 1 day and 1 month, and for MIGS patients, we add a visit at 1 week to check the pressure and adjust glaucoma medications.
Postoperative care varies for standalone procedures, but it is not burdensome and does not carry the risk and worry of traditional surgeries.
We have found that interventional glaucoma procedures do not affect patient flow. We schedule cataract and cataract-MIGS surgeries the same, without any dedicated time of day. Standalone procedures (such as Kahook Dual Blade, Visco 360 and XEN) are usually scheduled at the end of our cataract surgery schedule but can be intermixed with little disruption to the schedule.
The learning curve for these procedures is not steep, but it does require that cataract and refractive surgeons get comfortable using a gonio lens, which many of us do not do often. It takes practice to use the gonio lens in the non-dominant hand with the patient’s head turned, so we can implant a stent in the eye while centering the gonio lens under the microscope.
You can practice in the wet lab or, through some manufacturers, use a virtual reality simulator. You also can get comfortable visualizing the angle during your current surgeries. Once you can easily visualize the angle, you’re set up for successful placement of a stent.
Surgeons ask about my decision tree for surgical glaucoma treatment, but in fact the decision process is significantly influenced by insurance coverage. Insurance carriers vary widely in what they are willing to cover, despite the long-term benefits of reducing reliance on patients’ compliance with drops to preserve vision and avoid major surgery. Some insurers only cover MIGS during cataract surgery or only approve standalone surgery for severe glaucoma.
Thankfully, in a situation where coverage can dictate our choices, we usually have several options that will work well for any given patient. If you’re concerned about reimbursement, you might choose to start with Medicare patients because most MIGS are covered. When we want to perform a new procedure, we do so if we find it has a Medicare T code and set rate. If not, we choose a different procedure.
We have to be careful about coding for cataract-MIGS combinations when optometrists refer patients for that procedure. If we code MIGS as the primary procedure, then the referring optometrist will get a reduced comanagement fee for the cataract procedure and no fee for the MIGS procedure.
We need to bill cataract surgery as the primary procedure and the MIGS treatment as the secondary procedure so the referring doctor receives the full comanagement fee for the cataract and still none on the MIGS procedure.
As long as insurance companies make interventional treatment of glaucoma financially viable for cataract and refractive surgeons, surgeons will gravitate toward this approach.
These procedures will continue to increase our ability to intervene early and effectively to treat glaucoma, reducing the number of cases where poor compliance with drops leads to vision loss and the need for more advanced surgery
Farrell “Toby” Tyson, MD, is medical director, Tyson Eye, Cape Coral, FL. He was an investigator for the Glaukos iStent inject.