MIGS is usually recommended mild to moderate open-angle glaucoma, often alongside cataract surgery. It usually does not suit advanced disease, closed angles, active uveitic or neovascular glaucoma, or a hazy cornea.
Minimally Invasive Glaucoma Surgery (MIGS) is a group of surgical procedures designed to lower intraocular pressure using small, precise techniques. Compared with traditional glaucoma surgery, MIGS typically offers faster recovery, fewer complications, and a lower surgical burden.
Glaucoma treatment often begins with eye drops or laser procedures. In some patients, surgery becomes necessary to control eye pressure and protect the optic nerve from further damage.
MIGS is not appropriate for every patient. It works best for carefully selected individuals, and the decision to proceed must always be based on disease severity, rate of progression, and the patient’s lifetime risk of vision loss.
Dr Shibal Bhartiya is a fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator with over 25 years of experience. Her approach focuses on identifying risk before damage is irreversible, simplifying treatment decisions, and protecting vision long-term. Emphasis on early detection, risk assessment, and continuity of care. She is rated 5 stars across 1,500+ patient reviews on Google.
What is MIGS?
Minimally Invasive Glaucoma Surgery (MIGS) refers to a group of surgical techniques that improve the natural drainage of fluid from the eye, helping to lower intraocular pressure.
These procedures typically involve:
• very small surgical openings
• minimal disruption of eye tissues
• shorter recovery times
• lower complication rates than traditional surgery
Many MIGS procedures are performed at the time of cataract surgery, although some can be done as standalone procedures.
Why eye pressure matters in glaucoma
Glaucoma damages the optic nerve, which carries visual information from the eye to the brain. The most important modifiable risk factor for glaucoma progression is intraocular or eye pressure.
When eye pressure remains elevated over time, it can gradually damage the optic nerve and lead to irreversible vision loss.
Lowering eye pressure is therefore the main goal of glaucoma treatment.
Treatment options may include:
• eye drops
• laser procedures
• minimally invasive glaucoma surgery (MIGS)
• traditional glaucoma surgery
The choice depends on the stage of glaucoma, the rate of progression, and the patient’s individual risk factors. Please read Why Glaucoma May Progress Despite Treatment.
Types of MIGS procedures
Types of MIGS procedures
Several MIGS techniques are currently used in clinical practice. They work by improving the eye’s natural fluid drainage pathways through different mechanisms.
Trabecular bypass procedures target the trabecular meshwork, the main drainage tissue of the eye. Devices such as the iStent and iStent inject create a small channel that bypasses this tissue, improving fluid outflow directly into Schlemm’s canal. These are among the most commonly used MIGS devices worldwide and are frequently combined with cataract surgery.
Schlemm’s canal procedures enlarge or dilate Schlemm’s canal itself to improve drainage. Ab interno canaloplasty (ABiC) and the Hydrus Microstent work through this mechanism. The Hydrus also scaffolds the canal open along a longer segment, which can give more sustained pressure reduction.
Angle-based cutting procedures remove or incise the trabecular meshwork directly. The Kahook Dual Blade (KDB) and gonioscopy-assisted transluminal trabeculotomy (GATT) fall into this category. These tend to offer greater pressure reduction than micro-stent procedures and are used when more aggressive IOP lowering is needed while still avoiding traditional surgery.
Subconjunctival and suprachoroidal procedures create alternative drainage pathways outside the conventional drainage system. The XEN gel stent, for example, creates a small channel from inside the eye to the subconjunctival space. These procedures sit at the boundary between MIGS and conventional filtering surgery in terms of both effect and risk.
Each technique reduces resistance to fluid outflow through a different route. The choice of procedure depends on the severity of glaucoma, the target pressure required, and whether the surgery is being combined with cataract removal.
Available in India: iStent and iStent inject, Hydrus, Kahook Dual Blade, GATT, Suture GATT, and Bent Needle Goniotomy. The cost depends on the procedure and the implant.
Who may benefit from MIGS?
Now, the most important question: Is MIGS right for you?
MIGS procedures are most commonly recommended for patients who:
• have mild to moderate glaucoma
• require additional pressure reduction beyond eye drops
• are undergoing cataract surgery
• want to reduce the number of glaucoma medications
Because MIGS procedures are generally less aggressive than traditional glaucoma surgery, they are often used earlier in the disease course.
However, MIGS may not be appropriate for advanced or rapidly progressing glaucoma, where stronger pressure reduction may be required.
Advantages of MIGS
Minimally invasive glaucoma surgery offers several potential advantages:
• smaller surgical incisions
• faster visual recovery
• lower risk of serious complications
• the possibility of reducing glaucoma medications
• the ability to combine the procedure with cataract surgery
For carefully selected patients, MIGS can provide meaningful pressure reduction with relatively low surgical risk.
Limitations of MIGS
MIGS suits mild to moderate open-angle glaucoma, often alongside cataract surgery. It does not suit advanced disease, closed or scarred angles, active neovascular or uveitic glaucoma, or a hazy cornea.
Who Is Not a Good Candidate for MIGS?
MIGS lowers pressure by a modest amount through the eye’s natural drainage pathway. Some eyes need more than that, or have a pathway that cannot be used.
Advanced Glaucoma With a Low Target Pressure
If your optic nerve needs very low pressure, a modest drop will not protect it. Trabeculectomy or a tube usually serves these eyes better.
Closed or Scarred Drainage Angles
Most MIGS devices work inside the drainage angle. If scar tissue has closed it, the device has nothing to open into. In selected eyes, lens removal and clearing the angle may help. That is a specialist decision.
Active Neovascular or Uveitic Glaucoma
New blood vessels or active inflammation scar the drainage tissue and block small implants. These eyes usually need a tube, and the underlying cause needs treatment first.
A Poor View of the Angle
The surgeon must see the drainage angle through a special lens. Corneal scarring or swelling can make that impossible.
High Pressure in the Veins Outside the Eye
Sturge-Weber syndrome and some thyroid eye disease raise pressure in the veins that drain the eye. MIGS uses the same route, so it cannot overcome that pressure.
Many patients come to me for a second opinion with glaucoma that is hard to control. They use several drops, and some have had failed surgery. Their most common question is about MIGS.
My answer is almost always the same. MIGS will not restore vision. It lowers eye pressure, but less than conventional surgery. If your drainage angle is closed, MIGS is usually not an option. Success depends less on my skill as a surgeon than on the structure of your eye.
One patient had uveitic glaucoma and was on five drops, had already had a trabeculectomy, and yet, her eye pressures were uncontrolled. With almost 80% damage to her optic nerves and visual fields, she had been discussing a second surgery with her doctor. She asked whether MIGS could spare her a bigger operation. Her eye was inflamed and scarred, and the drainage tissue was already damaged. A small device had nothing healthy to work with. We controlled the inflammation first, then placed a tube. Three years later, her pressure is steady on two drops, and her visual fields are is stable.
MIGS suits some eyes very well. My job is to tell you honestly whether yours is one of them.
If MIGS does not suit your eye, Glaucoma Surgery in Gurgaon explains the alternatives.
Not sure whether MIGS suits your eye? Send your reports for a second opinion or call +91 88826 38735.
MIGS vs traditional glaucoma surgery
This is one of the most important questions a glaucoma patient can ask before agreeing to any procedure.
Trabeculectomy remains the gold standard for advanced glaucoma. It creates a new drainage opening in the eye wall, allowing fluid to drain under the conjunctiva. In experienced hands it can reduce eye pressure to very low levels — sometimes below 12 mmHg — making it the preferred option for patients with advanced disease or rapidly worsening visual fields. The trade-off is a longer recovery of four to six weeks, a higher complication rate, and the need for close post-operative monitoring.
Glaucoma drainage implants (such as the Ahmed valve or Baerveldt tube) are used when trabeculectomy has failed or is unlikely to succeed. They provide reliable long-term pressure control in complex cases but carry their own risks, including tube-related complications.
MIGS procedures offer more modest pressure reduction — typically in the range of 20 to 35 percent from baseline — but with significantly fewer complications, faster recovery of one to two weeks, and the ability to combine with cataract surgery in the same sitting. They are the right choice for patients with mild to moderate glaucoma who need pressure reduction beyond what drops can provide, but who do not yet need the aggressive lowering that trabeculectomy delivers.
The key principle is this: the treatment must match the disease. MIGS for a patient who needs a trabeculectomy is under-treatment. Trabeculectomy for a patient who would respond to MIGS is over-treatment. This is why an independent glaucoma assessment before surgery matters.
| MIGS | Trabeculectomy | Drainage Implant | |
|---|---|---|---|
| Typical IOP reduction | 20–35% | 30–50% | 30–50% |
| Recovery | 1–2 weeks | 4–6 weeks | 4–8 weeks |
| Best for | Mild–moderate glaucoma | Advanced glaucoma | Complex / refractory cases |
| Combined with cataract | Yes, usually | Yes | Yes |
| Complication profile | Low | Moderate–high | Moderate–high |
What to Expect With MIGS
Before Surgery
We confirm your drainage angle is open, using gonioscopy. We review your visual fields, OCT scans and target pressure. We also check that your cornea is clear. You keep using your drops until we advise otherwise. We review blood thinners with your physician.
On the Day
MIGS is a day-care procedure. Most patients have it during cataract surgery, under local or topical anaesthesia. It adds only a few minutes to the operation. You go home the same day. Please bring someone with you.
The First Two Weeks
Your vision is blurred at first. A little blood in the front of the eye is common after angle surgery. It usually clears within days. You use antibiotic and anti-inflammatory drops, and may continue some glaucoma drops. Do not rub the eye. Most people recover in one to two weeks.
Follow-Up
We see you at day 1, week 1 and month 1, then every 3 to 6 months. Each visit checks your pressure. We repeat OCT scans and visual fields to catch any slow rise early.
When to Call
Call us if you have sudden pain, falling vision or marked redness: +91 88826 38735 | +91 9818700269
The importance of long-term follow-up
Even after MIGS, glaucoma does not disappear. Patients must continue regular monitoring to ensure that eye pressure remains controlled and the optic nerve remains stable.
Follow-up visits may include:
• eye pressure measurement
• optic nerve evaluation
• visual field testing
• retinal imaging
Long-term monitoring helps detect any changes early and adjust treatment when necessary.
When patients seek a second opinion
Because glaucoma surgery decisions can affect long-term vision, some patients choose to seek an independent second opinion before proceeding with surgery.
A second opinion may help clarify:
• whether MIGS is appropriate
• whether alternative treatments are available
• what level of pressure reduction is required to protect vision
Clear communication and careful decision-making are important parts of responsible glaucoma care.
Key takeaways
• MIGS refers to minimally invasive glaucoma surgeries designed to lower eye pressure
• these procedures use small surgical techniques with faster recovery
• MIGS is most often used in mild to moderate glaucoma
• the procedure may reduce medication burden in some patients
• glaucoma still requires lifelong monitoring after surgery
Frequently asked questions about MIGS
What does MIGS stand for?
MIGS stands for Minimally Invasive Glaucoma Surgery. It refers to a group of surgical procedures that lower eye pressure using small, precise techniques with lower risk and faster recovery than traditional glaucoma surgery.
Who is a good candidate for MIGS?
MIGS is most appropriate for patients with mild to moderate glaucoma who need additional pressure reduction beyond eye drops, or who are already having cataract surgery and want to address glaucoma at the same time. It is generally not sufficient for advanced or rapidly progressing glaucoma.
Can MIGS replace eye drops?
In some patients, MIGS can reduce the number of drops required or eliminate them entirely. This depends on the procedure chosen, the pressure achieved after surgery, and the individual patient’s target IOP. Many patients still require at least one medication after MIGS.
Is MIGS combined with cataract surgery?
Yes. Many MIGS procedures are performed at the time of cataract surgery. This is one of the practical advantages of MIGS, patients can address both conditions under one anaesthetic with one recovery period.
How does MIGS compare to trabeculectomy?
MIGS offers lower pressure reduction than trabeculectomy, but with fewer complications and faster recovery. Trabeculectomy remains the better choice for advanced glaucoma where very low pressures are required. MIGS is appropriate for earlier-stage disease.
Should I get a second opinion before MIGS surgery?
Yes, if you have any doubt about whether surgery is necessary, whether the right procedure has been chosen, or whether your glaucoma truly needs surgical intervention at this stage. A second opinion from an independent glaucoma specialist gives you a clearer picture before you commit to any procedure.
How long does MIGS last?
Results vary by procedure and by patient. Some patients maintain good pressure control for many years. Others see pressure creep back up over time and require additional treatment. Regular follow-up after MIGS is essential, glaucoma does not stop requiring monitoring after surgery.
Is MIGS Right for Your Eye?
Not every eye with glaucoma is a MIGS eye. Your drainage angle, your optic nerve and your target pressure decide that. I check all three before I recommend any surgery.
Bring your reports to a consultation at my clinic in Gurgaon, or send them for a structured second opinion. Useful reports include visual fields, OCT scans, pressure records and your current drops.
Book an Appointment →
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Dr Shibal Bhartiya’s published work on MIGS:
Evaluating glaucoma surgeries in the MIGS context — a systematic review of outcomes across MIGS device categories. Available on PubMed.
Revisiting Results of Conventional Surgery: Trabeculectomy, Glaucoma Drainage Devices, and Deep Sclerectomy in the Era of MIGS— examines how to match procedure choice to disease severity and long-term risk. Available on PubMed.
Is GATT the Answer? — evaluates newer devices and techniques entering clinical practice. Available on PubMed.
Minimally Invasive Glaucoma Surgery-to Remove or Preserve the Trabecular Meshwork: That is the Question?– evaluating the structural and functional correlates of TM removal. Available on PubMed.
Minimally Invasive Glaucoma Surgeries, Health Economics, and the Moral Imperative of Equity in Glaucoma Care: Evaluating the ethics of surgical devices, considering equity and justice in glaucoma care. Available on PubMed.
Ethics of Glaucoma Widgets: MIGS and the Ethics of Surgical Decision-Making in Glaucoma, addresses how surgeons should communicate risk, benefit, and uncertainty to patients facing a surgery decision. Available on PubMed.
Current perspectives in tackling glaucoma blindness: And where MIGS fits in the glaucoma surgeons armamentairum. Available on PubMed.
This page is a part of the Glaucoma Hub. you may want to read about Glaucoma Progression, and Risk Stratification in Glaucoma. Other articles of interest could be Advanced Glaucoma Care in Gurgaon, What Good Glaucoma Care Actually Optimises For, What Happens If Glaucoma Is Left Untreated?, More Glaucoma Eye Drops is Not Better Glaucoma Care, 5 Mistakes Patients Make in Glaucoma Care and Do You Really Need Treatment for Glaucoma?
You may also want to read Glaucoma Second Opinion — Gurgaon, Online Glaucoma Consultation and Second Opinion Before Eye Surgery.
About the Author
This article was written by Dr Shibal Bhartiya, fellowship-trained glaucoma specialist and Mayo Clinic Research Collaborator, Clinical Director at Marengo Asia Hospitals, Gurugram, known for ethical, patient-centred glaucoma care and independent glaucoma second opinions. She is also the Program Director for Community Outreach & Wellness; and for the Marengo Asia International Institute of Neuro and Spine.
Dr Bhartiya has published peer-reviewed research onglaucoma management, examining how treatment decisions should balance medical evidence, patient preferences, and long-term vision outcomes. She is also a committed patient advocate and mainstream medical columnist, translating complex ophthalmic evidence into actionable public health insights across leading national platforms including NDTV and OnlyMyHealth
As Editor-in-Chief of Clinical and Experimental Vision and Eye Research and Executive Editor of the Journal of Current Glaucoma Practice (Pubmed Indexed, official journal of the International Society of Glaucoma Surgery). Her 200+ publications, including 90+ PubMed-indexed publications and 28 edited textbooks span glaucoma biology, surgical outcomes, health equity, and emerging diagnostics.
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Last Reviewed: October 2026