What Is MIGS Surgery? A Modern Method to Treat Glaucoma Safely

Glaucoma quietly damages your optic nerve long before you notice any vision changes. Unfortunately, for millions of patients, standard eye drops simply aren’t enough to stop it. Studies consistently show that minimally invasive glaucoma surgery, or MIGS, effectively lowers eye pressure by an average of 20 to 30 percent, while carrying significantly fewer risks than traditional glaucoma surgery.

Minimally invasive glaucoma surgery (MIGS) uses microscopic tools and tiny incisions to work with your eye’s natural drainage system rather than against it, offering a gentler path to protecting your sight.

MIGS fills a critical gap in glaucoma care: one that medications and laser therapy can’t always close yet doesn’t demand the serious risks that come with conventional surgical procedures.

This guide explains what MIGS surgery is, how it works, the specific techniques available, and why minimally invasive glaucoma surgery might be the right choice for preserving your vision from this progressive, sight-stealing disease.

What is MIGS and How Does it Work?

MIGS stands for minimally invasive glaucoma surgery. The name represents a group of surgical procedures designed to lower intraocular pressure and prevent further optic nerve damage. Rather than relying on aggressive surgical intervention, MIGS procedures work by enhancing the natural outflow of aqueous humor, the fluid your eye continuously produces, through micro-invasive techniques that leave surrounding tissue largely undisturbed.

Think of your eye’s drainage system like a household plumbing network. When the pipes become blocked or resistant, pressure builds. MIGS surgery targets those blockages directly, restoring flow without tearing apart the entire system.

Eye surgeons perform these procedures using what’s called an ab interno approach—accessing your eye’s drainage structures from the inside through a small, clear corneal incision rather than cutting through the outer layers of your eye. This internal route gives the surgeon direct visibility of the anatomical target under microscopic control while keeping tissue disruption to a minimum.

Different MIGS procedures target different parts of your eye’s natural drainage pathway. Some bypass or remove the trabecular meshwork, which is the tissue responsible for most drainage resistance in the eye. Others access the suprachoroidal space, the area between your retina and the eye wall, or create entirely new drainage channels leading to the subconjunctival space. Certain techniques take a different approach altogether, reducing fluid production by treating the ciliary body directly.

All MIGS procedures share five defining characteristics:

• High safety profile
• Minimal disruption to normal eye anatomy
• Ab interno surgical approach
• Meaningful IOP-lowering effect (at least 20% reduction)
• Ease of use with rapid recovery

Because MIGS prioritizes your safety above all else, serious complications occur far less frequently than with traditional glaucoma surgery. The tradeoff is that MIGS may not achieve the dramatic pressure reductions that more invasive procedures can deliver; however, for many patients, that balance is exactly right.

MIGS Procedures and Techniques

Several distinct MIGS techniques target different parts of your eye’s drainage system. Each approach addresses the same fundamental problem of elevated intraocular pressure (IOP), but through different anatomical pathways.

Stents that bypass the trabecular meshwork

Trabecular meshwork bypass stents create direct channels from your anterior chamber into Schlemm’s canal, working around the tissue responsible for most drainage resistance.

The iStent devices are titanium micro-bypass stents less than 1mm long that facilitate physiologic outflow. Their second-generation counterpart, the iStent inject, deploys two stents simultaneously to increase outflow through multiple channels. The Hydrus® Microstent takes a broader approach, spanning 90 degrees of Schlemm’s canal using an 8mm nitinol scaffold, with studies showing 59 percent of patients remained medication-free after 5 years.

Techniques that remove trabecular tissue entirely

Rather than bypassing the blockage, some procedures simply remove it.

The trabectome uses electrocautery to ablate trabecular tissue directly, while the Kahook Dual Blade® (KDB) performs precise tissue excision using dual parallel blades. For patients with high-pressure glaucoma, GATT (Gonioscopy-Assisted Transluminal Trabeculotomy) performs a full 360-degree trabeculotomy, achieving IOP reductions of 30-40% which is one of the most aggressive pressure-lowering options within the MIGS category.

Drainage and fluid-reducing approaches

Canaloplasty dilates Schlemm’s canal itself using a microcatheter and viscoelastic, with studies showing an IOP reduction from 23.8 to 15.2 mmHg at 3 years. The XEN gel stent creates an entirely new drainage pathway through a 6mm porcine gelatin tube, routing fluid to the subconjunctival space and achieving significant IOP reduction, although the procedure has an elevated risk of severe complications. The PreserFlo™ MicroShunt accomplishes similar subconjunctival drainage using a biocompatible SIBS polymer, with studies showing average IOP reduction results of 15 mmHg or less.

For patients where reducing fluid production makes more sense than improving drainage, Endocyclophotocoagulation (ECP) applies laser energy directly to the ciliary body, the structure that produces aqueous humor, which effectively turns down the pressure at its source.

The right technique depends entirely on your specific type of glaucoma, your current eye pressure, and what your surgeon determines will provide the most durable protection for your optic nerve. The expert team of ophthalmologists at Chang Eye Group can discuss the best options for your unique eye conditions at one of our convenient Pittsburgh locations.

Why Choose MIGS Surgery for Glaucoma?

When medications and laser therapy are no longer able to adequately control your eye pressure, you face a difficult choice. Traditional surgeries like trabeculectomy and tube shunts can achieve significant pressure reduction, but they have serious risks that many patients prefer to avoid. MIGS sits between these options, delivering meaningful IOP reduction without exposing you to the more severe complications that conventional procedures bring.

MIGS reduces these risks and have extremely low complication rates versus traditional surgical procedures.

Who benefits most from MIGS

MIGS works best for patients with mild to moderate primary open-angle glaucoma. You’re a strong candidate if:

• Glaucoma medications cause side effects that affect your daily comfort
• Keeping up with daily eye drop schedules has become a challenge
• Your eye pressure remains elevated despite other treatments

Many patients also combine MIGS with cataract surgery. Since both procedures share similar access points, your surgeon can address both conditions simultaneously, adding only a few minutes to your overall procedure time.

Recovery moves quickly. Most patients resume normal activities within days to a week, compared to the several weeks or months that conventional surgery typically demands.

One important consideration: if you have advanced glaucoma requiring very low target pressures, traditional surgical approaches may still be more appropriate for your situation. Your eye doctor will evaluate your specific condition and pressure goals before recommending any procedure.

Schedule a glaucoma evaluation at Chang Eye Group in Pittsburgh to determine whether MIGS matches your needs and which specific technique offers you the best path to protecting your sight.

Protecting Your Vision with MIGS

Glaucoma doesn’t wait, and neither should you.

When medications fall short and traditional surgery feels like too great a risk, MIGS offers a proven middle path toward meaningful pressure reduction, faster recovery, and a safety profile that conventional procedures simply cannot match.

Your eyesight is too valuable to leave unprotected while glaucoma quietly continues its damage. Whether you’re struggling with medication side effects, finding daily eye drops difficult to manage, or facing elevated pressure despite treatment, a MIGS procedure may be exactly what your vision needs.

Don’t wait for your glaucoma to advance before exploring your options. Schedule a glaucoma evaluation at Chang Eye Group in Pittsburgh to find out which MIGS technique matches your specific condition and helps preserve the sight you depend on every day.