When eye pressure won’t drop with drops or laser treatment, surgery becomes the next step. For many people with glaucoma, that means choosing between a well-established procedure like trabeculectomy and newer options like MIGS. It’s not about which is better-it’s about which is right for your eyes, your lifestyle, and your long-term vision goals.

What Glaucoma Surgery Actually Does

Glaucoma isn’t just about high pressure. It’s about what that pressure does to your optic nerve over time. Left unchecked, it slowly steals your peripheral vision, often without symptoms until it’s too late. Surgery doesn’t cure glaucoma. It doesn’t restore lost sight. But it can stop it from getting worse-by lowering the pressure inside your eye, known as intraocular pressure (IOP).

The goal? Get IOP down to a level your optic nerve can handle. For some, that’s 18 mmHg. For others with advanced damage, it’s 12 mmHg or lower. Medications help, but they’re not always enough. Laser treatments like SLT work well for early cases, but when they wear off or aren’t strong enough, surgery steps in.

Trabeculectomy: The Gold Standard That Still Works

First developed in the 1960s by British surgeon John Cairns, trabeculectomy is the original surgical fix for glaucoma. It’s still the most effective at lowering pressure-especially for people who need very low targets.

Here’s how it works: A small flap is cut in the white part of your eye (the sclera), and a tiny piece of the drainage tissue (trabecular meshwork) is removed. This creates a new path for fluid to escape, forming a small blister-like pocket under the eyelid called a bleb. Fluid collects there and slowly soaks away, lowering pressure.

The numbers speak for themselves. According to Mass Eye and Ear’s 2023 data, trabeculectomy reduces IOP by 40-60% in about 85-90% of patients at one year. That often means pressure drops to 5-15 mmHg. For someone with severe glaucoma, that’s life-changing.

But it comes with trade-offs. Recovery takes 4-6 weeks. You’ll need frequent check-ups for 3-6 months. There’s a 10-15% chance of bleb leaks, where the fluid escapes too much. A 5-15% risk of serious complications like infection (endophthalmitis) or dangerously low pressure (hypotony). And about 10-20% of blebs fail within five years.

It’s a powerful tool-but it’s not gentle. Surgeons need to do 50 to 100 of these before they’re truly comfortable. That’s why it’s usually reserved for advanced cases or when other treatments have failed.

MIGS: The Rise of Minimally Invasive Glaucoma Surgery

Around 2012, everything changed. The FDA approved the iStent, the first MIGS device. Since then, a whole new category has exploded. Today, MIGS makes up 65% of all standalone glaucoma surgeries in the U.S., according to Glaucoma Today’s January-February 2025 report.

MIGS stands for Minimally Invasive Glaucoma Surgery. That means tiny incisions-less than 1.5mm-no cutting of the sclera, and almost no disruption to the eye’s natural structure. Most MIGS procedures are done at the same time as cataract surgery, which makes them even more appealing.

There are several types:

• iStent inject: Two tiny stents (1mm long) placed in the drainage channel. Reduces IOP by 25-30%.
• Hydrus Microstent: A small scaffold that stretches the drainage canal. Works well for moderate glaucoma.
• Xen Gel Stent: A 6mm soft tube that drains fluid to the surface. Often used when other MIGS isn’t enough.
• GATT (Gonioscopy-Assisted Transluminal Trabeculotomy): A thread is threaded through the drainage system to open it up. Achieves 30-35% IOP reduction.

The big wins? Faster recovery. Most patients are back to normal in 1-2 weeks. Complication rates are under 3%. No bleb means no risk of infection from a leaky pocket. And you’ll likely need fewer eye drops-on average, 1.5 to 2 fewer per day.

But MIGS has limits. It doesn’t lower pressure as much as trabeculectomy. Most MIGS procedures bring IOP down to 15-18 mmHg. That’s fine for early or moderate glaucoma, but not enough if you need to hit 12 mmHg. Long-term data is still being gathered. We don’t yet know if these devices last 10, 15, or 20 years.

How They Compare: Pressure, Risk, and Recovery

Comparison of Glaucoma Surgical Options

Procedure	Average IOP Reduction	Target IOP Range	Complication Rate	Recovery Time	Typical Use Case
Trabeculectomy	40-60%	5-15 mmHg	5-15%	4-6 weeks	Advanced glaucoma, young patients, failed MIGS
MIGS (e.g., iStent, Xen)	20-30%	15-18 mmHg	1-3%	1-2 weeks	Mild to moderate glaucoma, combined with cataract surgery
SLT (Laser)	20-30%	15-20 mmHg	<1%	1-2 days	First-line treatment for open-angle glaucoma

The numbers show a clear pattern: MIGS is safer and faster, but less powerful. Trabeculectomy is the heavy lifter, but it’s risky. And SLT? It’s now the first choice for most people with open-angle glaucoma. The LiGHT trial showed SLT works just as well as eye drops over three years-with fewer side effects and lower costs.

Who Gets Which Surgery?

There’s no one-size-fits-all. The decision depends on three things: how bad your glaucoma is, how low your target pressure needs to be, and your overall health.

• If you have early glaucoma and your pressure is only slightly high, SLT is your best first move. If that doesn’t last, a MIGS device like iStent inject can be added during cataract surgery.
• If you have moderate glaucoma and you’re already on multiple drops, MIGS is a smart choice. It reduces medication burden and lowers pressure safely.
• If you have advanced glaucoma or your pressure is still high after MIGS, trabeculectomy or a tube shunt is likely needed. These give you the deepest pressure drop.
• If you’re young and have decades ahead, your surgeon might lean toward trabeculectomy. MIGS devices may not last long enough.
• If you’re older and have cataracts, combining MIGS with cataract surgery is often the smartest move.

What’s Changing in 2026?

The field is moving fast. Direct Selective Laser Trabeculoplasty (DSLT) is now being tested-no contact needed, full 360° treatment in seconds. It’s a bit more irritating post-op, but it’s promising.

Suprachoroidal shunts are another new direction. Instead of draining fluid to the surface, they send it to a space behind the eye. Early results show good pressure control with fewer complications than trabeculectomy.

And the trend? Earlier intervention. No longer waiting until drops fail. Surgeons are now using MIGS and SLT at the first sign of progression. The goal isn’t just to avoid blindness-it’s to avoid lifelong medication dependence.

What You Should Ask Your Surgeon

Don’t just say yes to the first option. Ask:

• What’s my target pressure, and how does this surgery get me there?
• What’s the chance this will need to be repeated in 5 years?
• How many of these have you done? What’s your complication rate?
• Will I still need eye drops after surgery? How many?
• What happens if this doesn’t work? Can I still have a trabeculectomy later?

Final Thoughts

Glaucoma surgery isn’t about picking the most advanced or the most popular option. It’s about matching the tool to the job. Trabeculectomy still saves vision in advanced cases. MIGS is changing lives by making surgery safer and more accessible. And SLT? It’s now the go-to starting point for most.

The future of glaucoma care isn’t one surgery-it’s a personalized pathway. Laser first. MIGS next. Trabeculectomy if needed. The goal is simple: protect your vision, with the least disruption to your life.