The development of microinvasive glaucoma surgery (MIGS) has been an exciting journey for ophthalmologists. Since I began performing MIGS in January 2015, its safety and efficacy has encouraged me to suggest MIGS to all appropriate candidates.1 Because this could be a new concept for patients (most of whom have never even heard of MIGS), we must be prepared to explain the procedures and to lay out their risks and benefits.
Most MIGS procedures can be performed alone or combined with cataract surgery, with the aim of halting or preventing damage to the optic nerve. The MIGS procedures I currently offer are Xen Gel Stent (Allergan) implantation and use of the Kahook Dual Blade (KDB, New World Medical). When I evaluate cataract surgery patients who have concomitant glaucoma or patients with glaucoma only, I offer these MIGS options in the following two situations.
Situation No. 1: Patients whose IOP is uncontrolled by medical treatment. Past glaucoma laser procedures do not affect candidacy for MIGS. For example, patients may have had selective laser trabeculoplasty (SLT) in the past. Several MIGS procedures are efficacious in eyes with failed SLT, so I often recommend them over standard surgery.
Situation No. 2: Patients who have stable IOP but a high medication burden. As the number of topical drops required to maintain target IOP increases, patient adherence declines. As a result, we can assume that patients who use two or more drops are not always compliant with therapy. In addition to adherence problems, patients with glaucoma who take several drops can struggle with inconvenient or confusing regimens, high prescription costs, and toxicity to the ocular surface. These factors make a low-risk MIGS procedure a prudent alternative in appropriate situations.
DISCUSSING MIGS OPTIONS
I explain MIGS procedures to patients in a straightforward manner. I refer to it as a mini-surgery. I give patients brochures on the Xen Gel Stent and KDB, with detailed illustrations and explanations of how the procedures are performed. As with any procedure, some patients want to put faith in the surgeon and hear as little as possible about the surgery, while others have a need for detailed information. We can also show curious patients a video if they desire.
When patients experience disease progression or their IOP is uncontrolled despite treatment, I explain that their pressure is too high or that they have optic nerve damage. If the patient is already going to undergo cataract surgery, I recommend adding this safe, 5-minute MIGS mini-surgery at the end. I explain that it has a high probability to stabilize pressure and prevent progression. I also explain the risks associated with MIGS surgery. For example, some Xen patients develop conjunctival fibrosis and require a needling procedure to reestablish aqueous outflow.
Patients with a high medication burden, perhaps facing problems with cost or ocular surface inflammation, receive the same explanation of the MIGS procedures, but I also discuss how MIGS could reduce their dependence on medications, reduce side effects, and improve quality of life. In our clinic, we have every newly diagnosed glaucoma patient spend time with a trained nurse to discuss glaucoma, its associated risks, and its treatment. Similarly, we put an emphasis on patient education for those with glaucoma who need cataract surgery. Patients have time to ask questions of trained health professionals before they make any decisions.
CHOICES FOR TODAY AND TOMORROW
Presented with the benefits of MIGS, most patients opt for a combined procedure. They feel that, because they are getting surgery anyway, adding this mini-surgery to address glaucoma is wise. With personal experience now out to 3 years postoperative, my patients have been pleased with the outcomes of MIGS procedures. Their IOPs are lower, allowing us to reduce or eliminate their use of medications. Without the use of so many drops, the ocular surface clears up, patients’ eyes are more comfortable, and their quality of life improves.
Even if cataract patients with glaucoma choose not to have a combined procedure, or if they do not meet my two primary criteria for MIGS candidacy, they can have the Xen procedure as a standalone surgery later if their glaucoma becomes uncontrolled. The safety and minimally invasive nature of this and other MIGS procedures makes them flexible treatment options that can be returned to at any point in the future.
1. Mansouri K, Guidotti J, Rao HL, et al. Prospective evaluation of standalone Xen gel implant and combined phacoemulsification-Xen gel implant surgery: 1-year results. J Glaucoma. 2018;27(2):140-147.
2. Muir KW, Lee PP. Glaucoma medication adherence: room for improvement in both performance and measurement. Arch Ophthalmol. 2011;129(2):243-245.