Table of Contents
- Understanding Glaucoma and Its Impact on Vision
- The Evolution of Glaucoma Treatment: From Traditional Surgery to MIGS
- How MIGS Works: Techniques and Technologies
- Comparison of Different MIGS Devices
- Benefits of MIGS: Why It’s a Game-Changer
- Is MIGS Right for You? Evaluating Candidacy and Risks
- What to Expect During and After MIGS
- MIGS Comparison to Traditional Glaucoma Surgeries and Medications
- Conclusion
- FAQs
Glaucoma is a major cause of permanent blindness worldwide and often occurs silently over the years. The condition revolves around increased pressure inside the eye (intraocular pressure, or IOP), which slowly damages the optic nerve and causes irreversible loss of vision. Traditionally, glaucoma has posed a tricky clinical challenge; strong eye drops and major surgical operations have been mainstays, but both carry their own risks and side effects. On the other hand, Minimally Invasive Glaucoma Surgery (MIGS), a new procedure for glaucoma, is changing how we approach this sight-threatening disease.
In this blog, we’ll demystify MIGS, decode clinical aspects of this one of the advanced surgical procedures for glaucoma, and explain who stands to benefit the most, all in a way that’s clear, relatable, and practical for anyone facing glaucoma concerns.
Understanding Glaucoma and Its Impact on Vision
Glaucoma is of two types (primary open-angle glaucoma and angle-closure glaucoma), where optic nerve damage is most often caused by increased IOP. Because the optic nerve acts like a cable carrying visual signals from the eye to the brain, gradual nerve fiber loss results in “tunnel vision,” blind spots, and ultimately, total blindness if untreated.
Clinically, glaucoma is called the “silent thief of sight” as it typically has no warning signs until significant vision is lost. Risk factors include age, family history, high IOP, certain ethnic backgrounds, and other health conditions like diabetes or severe myopia.
Traditional glaucoma management starts with medications (eye drops to lower eye pressure) and may escalate to laser treatments or incisional surgeries (like trabeculectomy or glaucoma drainage implants) when drops and laser aren’t enough. However, these traditional surgical procedures for glaucoma can have significant risks, including eye infections, heavy bleeding, scarring, long-term vision changes, and long recovery periods.
The Evolution of Glaucoma Treatment: From Traditional Surgery to MIGS
For decades, eye doctors relied on big surgeries like trabeculectomy or tube shunt implants for advanced glaucoma. While highly effective in lowering IOP, these procedures were invasive, stressful for patients, and carried higher risks of complications such as hypotony (too-low eye pressure), excessive scarring, bleb leaks, or lifelong vulnerability to eye infections.
MIGS is a relatively new glaucoma surgery for mild-to-moderate glaucoma. These procedures are less traumatic to ocular tissues, use smaller incisions, and often result in much faster healing. Because of this, MIGS has rapidly become a vital part of a modern glaucoma clinic’s toolkit.
How MIGS Works: Techniques and Technologies
MIGS surgery, designed to safely lower eye pressure by improving how the fluid inside the eye (aqueous humour) drains out.
Principles of MIGS:
- Performed through micro-incisions, sometimes as small as 1–2 mm
- Use of specialized micro-stents, shunts, or microcatheters (often made of titanium or other biocompatible materials)
- Minimal dissection or manipulation of major tissues compared to traditional surgery
Categories of MIGS based on their target tissue and drainage pathway:
- Trabecular bypass devices (e.g., iStent, Hydrus Microstent): Placed into Schlemm’s canal to help fluid flow through the eye’s main drainage channel.
- Suprachoroidal shunts (e.g., CyPass, now withdrawn in some countries): Create a new pathway to the space between the sclera and choroid.
- Subconjunctival devices (e.g., XEN Gel Stent): Drain fluid under the conjunctiva, like mini versions of tube shunt surgeries.
- Trabeculotomy or Goniotomy knives: Devices create small cuts in the drainage meshwork for better outflow, sometimes without an implanted device.
Comparison of Different MIGS Devices
| MIGS Devices | Mechanism | Clinical Uses |
| iStent, Hydrus | Stent in the trabecular meshwork | Open-angle glaucoma, as an add-on or stand-alone |
| XEN Gel Stent | Microshunt under the conjunctiva | Open-angle or refractory glaucoma |
| GATT, Trabectome | Bypass the trabecular meshwork | Open-angle, young patients, add-on laser |
| Kahook Dual Blade | Removes strip of meshwork tissue | Early treatment, adjunct to cataract surgery |
Benefits of MIGS: Why It’s a Game-Changer
The rapid adoption of MIGS is not without reason. MIGS procedures offer a greatly improved safety profile, with fewer complications compared to bigger glaucoma surgeries. Key clinical benefits include:
- Faster recovery: Most patients can resume normal life and work in a few days, instead of weeks.
- Reduced need for ongoing drops: Lower dependence on daily eye drops, which many patients find difficult to use consistently.
- Less risk of infection or bleeding: No large “bleb” or external drainage pouch as seen in older surgeries.
- Outpatient procedure: Most MIGS take under 30 minutes and do not require an overnight hospital stay.
- Permanent solution: While no surgery can cure glaucoma, MIGS can give long-term IOP control and stable vision for many years.
Is MIGS Right for You? Evaluating Candidacy and Risks
MIGS is mainly intended for people with mild-to-moderate open-angle glaucoma, especially if eye pressure is not well-controlled with eye drops but is not dangerously high.
Suitable MIGS candidates have
- Open-angle glaucoma
- Early to moderate disease
- Cataract surgery (MIGS can often be added at the same time)
- Poor tolerance or compliance with eye drops
MIGS may not be suitable for:
- Advanced glaucoma with significant vision loss, where traditional surgery is still best
- Closed-angle or angle-closure glaucoma (unless angle is opened after lens removal)
- Eyes with significant scarring or abnormal anatomy
What to Expect During and After MIGS?
On the day of your procedure:
- Typically done under local or topical anaesthesia (numbing drops) in the operating room.
- The procedure itself takes about 15–30 minutes, often through a microscopic incision less than a few millimetres long.
- Most patients feel only mild pressure or discomfort; pain is rare.
After MIGS surgery:
- You will go home the same day
- Mild irritation, redness, or blurred vision for a day or two
- Instructions to use anti-inflammatory and antibiotic drops for several weeks
- Light activity can be resumed after a couple of days; avoid eye rubbing, swimming, or heavy lifting until cleared by your doctor
- Regular checks are needed to make sure the eye pressure drops to and remains at the new target level
- In most cases, vision stabilizes quickly, and people can return to routine tasks and work within 3–5 days.
MIGS Comparison to Traditional Glaucoma Surgeries and Medications
| Aspect | MIGS | Traditional Surgery | Eye Drops/Medications |
| Invasiveness | Minimal | Significant | None |
| Recovery Period | 2–5 days | Weeks | None |
| Complication Rate | Low | Higher | Side effects possible |
| Effect on Eye Structure | Preserves tissue | Alters/drains tissue | None |
| Drop Dependency | Reduced/often stopped | Often stopped | Continuous |
| Suitable for Cataracts | Yes (combo possible) | Sometimes | Yes |
| Longevity of Effect | Years | Years | As long as drops are used |
Conclusion
Minimally Invasive Glaucoma Surgery offers real hope, a way to protect vision and dramatically reduce the side effects and complications that have held back many traditional glaucoma treatments. MIGS fits well for patients who need better pressure control but want the benefits of safer, more convenient surgery and a rapid return to daily life. With ongoing progress in this field, talk to your eye specialist about whether MIGS, alone or along with cataract surgery, might be your next step towards lifelong healthy vision.
