If your glaucoma isn’t well controlled with eye drops alone, surgery may be the next step in preserving your vision. But which type of surgery is right for you? With advances in minimally invasive glaucoma surgery (MIGS), patients now have more options than ever before. Understanding the differences between MIGS and traditional glaucoma surgery can help you have an informed conversation with your ophthalmologist about the best approach for your individual situation.

As a glaucoma specialist with extensive experience in both MIGS and traditional surgical techniques, and through my involvement with the International Glaucoma Surgery Registry, I’ve seen firsthand how the right surgical choice can significantly improve outcomes and quality of life for glaucoma patients. This guide will walk you through the key differences, recovery expectations, success rates, and factors that determine which procedure suits your needs.

Understanding Your Options

What is MIGS (Minimally Invasive Glaucoma Surgery)?

MIGS represents a newer category of glaucoma procedures designed to lower intraocular pressure (IOP) with minimal disruption to the eye’s natural anatomy. These procedures use microscopic incisions and tiny devices to enhance the eye’s existing drainage system, allowing fluid to flow more freely and reducing pressure.

Common MIGS procedures include the iStent (a tiny titanium stent), Hydrus Microstent (a flexible scaffold device), MINIject (a soft sponge-like device), and the iTrack Advance (a microcatheter procedure). The key characteristic of MIGS is that it works with your eye’s natural drainage pathways rather than creating entirely new ones.

MIGS procedures are typically performed through incisions of 2mm or less, often at the same time as cataract surgery. The recovery is generally faster and the risk profile lower compared to traditional approaches, making MIGS an attractive option for patients with mild to moderate glaucoma.

What is Traditional Glaucoma Surgery?

Traditional glaucoma surgery includes procedures like trabeculectomy and tube shunt implants. These more established surgical techniques create a new drainage pathway for fluid to leave the eye, bypassing the eye’s natural drainage system that has become blocked or inefficient.

In a trabeculectomy, the surgeon creates a small flap in the sclera (the white part of the eye) and removes a tiny piece of tissue to allow fluid to drain into a space under the conjunctiva, forming what’s called a “bleb.” Tube shunt procedures involve placing a small tube inside the eye connected to a plate on the outside, creating a controlled drainage route.

Traditional glaucoma surgery is typically recommended when glaucoma is more advanced, when other treatments have failed, or when a more significant reduction in eye pressure is needed. These procedures have a long track record of effectiveness and remain the gold standard for achieving substantial pressure reduction.

MIGS vs Traditional Surgery: Key Differences

Understanding how these approaches differ can help clarify which might be more suitable for your situation.

Factor	MIGS	Traditional Surgery
Invasiveness	Micro-incisions (1-2mm), minimal tissue disruption	Larger incisions, creates new drainage pathway outside the eye
Recovery Time	Days to 1-2 weeks typical	4-6 weeks typical, sometimes longer
Pressure Reduction	Moderate (20-30% reduction typical)	Significant (30-50%+ reduction possible)
Medication Reduction	Often reduces number of drops needed	May eliminate drops entirely in many cases
Complication Risk	Lower risk profile overall	Higher risk but manageable with experienced surgeon
Ideal Candidates	Mild-moderate glaucoma, often combined with cataract surgery	Moderate-severe glaucoma, previous treatments unsuccessful
Anaesthesia	Usually local or topical	Local anaesthesia
Hospital Stay	Day procedure, home same day	Usually day procedure, occasionally overnight observation

Invasiveness and Surgical Approach: MIGS procedures are performed through tiny incisions that often don’t require sutures. The surgical trauma is minimal, which contributes to faster healing. Traditional surgery involves creating a filtration site or implanting a drainage device, which requires more extensive tissue manipulation and typically needs sutures.

Pressure Reduction Capacity: Whilst MIGS effectively lowers IOP by 20-30% on average, traditional surgery can achieve more dramatic pressure reductions of 30-50% or more. For patients with very high pressures or advanced glaucoma damage, the more powerful reduction from traditional surgery may be necessary to prevent further vision loss.

Recovery Timeline: MIGS patients often return to normal activities within days to two weeks, with minimal discomfort. Traditional surgery requires a more cautious recovery period of 4-6 weeks, with activity restrictions and more intensive post-operative care to ensure proper healing of the surgical site.

Medication Burden: Many MIGS patients can reduce their glaucoma medication regimen, though some may still need drops. Traditional surgery has a higher likelihood of eliminating the need for glaucoma drops entirely, though this varies by individual and some patients may still require medication for optimal pressure control.

Risk Profile: MIGS procedures have a lower rate of serious complications such as infection, bleeding, or vision-threatening hypotony (pressure too low). Traditional surgery, whilst generally safe in experienced hands, carries higher risks that must be weighed against the greater pressure-lowering benefit.

Recovery: MIGS vs Traditional Glaucoma Surgery

MIGS Recovery Timeline

Days 1-3: Most patients experience mild discomfort, light sensitivity, and some blurred vision. You’ll use prescribed eye drops to prevent infection and inflammation. Many patients are surprised by how quickly they feel relatively normal.

Week 1-2: Vision typically stabilises and improves. You’ll avoid heavy lifting, strenuous exercise, and swimming, but can generally resume desk work and light activities. Follow-up appointments monitor your eye pressure and healing progress.

Month 1: Most activity restrictions are lifted. Your ophthalmologist will assess your pressure reduction and adjust medications as needed. Many patients are back to their full normal routine by this point.

The faster recovery with MIGS is one of its most appealing features, particularly for patients who are also having cataract surgery and want to minimise disruption to their daily lives.

Traditional Surgery Recovery Timeline

First Week: Expect more significant discomfort, redness, and vision fluctuation. You’ll need to be very careful about protecting your eye, avoiding any pressure or trauma to the surgical site. Frequent eye drops are required, and you may need to sleep with an eye shield.

Weeks 2-6: Gradual healing occurs, with regular monitoring of the filtration site (bleb) if you’ve had a trabeculectomy. Your surgeon may perform minor procedures in the office to adjust the flow through the new drainage pathway. Activity restrictions remain in place to protect the healing surgical site.

Months 2-3: Most patients have stabilised by this point, though some require longer healing periods. The bleb continues to mature, and your pressure should reach its target range. You’ll continue regular follow-up appointments to monitor long-term success.

Driving: MIGS patients can often drive within days if vision is adequate. Traditional surgery patients typically need to wait 1-2 weeks or until cleared by their surgeon.

Work: Desk work may resume within a week for MIGS, compared to 2-4 weeks for traditional surgery. Jobs involving heavy lifting or physical labour require longer time off for both procedures.

Exercise: Light walking is fine for both procedures early on. MIGS patients can usually return to full exercise in 2-3 weeks, whilst traditional surgery patients should wait 6-8 weeks before resuming vigorous activity.

How Effective Are These Procedures?

MIGS Success Rates

Clinical research, including data from the International Glaucoma Surgery Registry, shows that MIGS procedures achieve meaningful IOP reduction in the majority of patients. Studies demonstrate that iStent procedures reduce pressure by an average of 20-25%, with many patients able to reduce their medication burden.

Long-term data extending to five years shows that MIGS maintains pressure control effectively, though some patients may eventually need additional treatment as glaucoma is a progressive disease. The success rate for achieving target pressure with reduced medications ranges from 60-80% depending on the specific device and patient characteristics.

One of MIGS’s strengths is its repeatability—if additional pressure lowering is needed later, patients can often undergo another MIGS procedure or progress to traditional surgery without having compromised their options.

Traditional Surgery Success Rates

Trabeculectomy has decades of evidence supporting its effectiveness, with success rates of 60-90% for achieving target pressure at five years, depending on how success is defined and patient factors. It remains the most powerful surgical option for lowering IOP.

Tube shunt procedures show similar long-term success, particularly in cases where trabeculectomy has failed or is less likely to succeed. These procedures have proven track records in even the most challenging glaucoma cases.

Whilst traditional surgery carries higher risks, when performed by experienced glaucoma surgeons, serious complications are uncommon and most patients achieve excellent long-term pressure control with preserved vision.

Both approaches are evidence-based and effective—the key is matching the procedure to the patient’s specific clinical situation and needs.

Which Glaucoma Surgery is Right for You?

You May Be a Candidate for MIGS If:

• You have mild to moderate glaucoma that needs better control
• You’re already planning cataract surgery (MIGS can be combined)
• You prefer a less invasive approach with faster recovery
• Your current pressure isn’t extremely high
• You’re using multiple glaucoma eye drops and want to reduce this burden
• You have good remaining vision and want to minimise surgical risk
• Your glaucoma type is suitable for MIGS (open-angle glaucoma)

Traditional Surgery May Be Better If:

• You have moderate to severe glaucoma with significant damage
• Your eye pressure is very high despite maximum medical therapy
• Previous treatments including MIGS have been unsuccessful
• You need the maximum possible pressure reduction
• Your glaucoma is rapidly progressing
• You have certain types of glaucoma that respond better to traditional approaches
• Your ophthalmologist determines the risk-benefit ratio favours more aggressive intervention

Factors Your Surgeon Considers:

Glaucoma Severity and Type: The extent of optic nerve damage and visual field loss heavily influences surgical choice. Advanced glaucoma typically requires traditional surgery’s more powerful pressure reduction.

Current Eye Pressure Levels: Very high IOP (above 30 mmHg) often needs traditional surgery to achieve safe pressure levels quickly.

Number of Medications Currently Using: If you’re already on maximum medical therapy and still not controlled, this suggests you may need traditional surgery’s greater effect.

Previous Surgeries or Treatments: Your eye’s surgical history affects which procedures are feasible and likely to succeed.

Presence of Cataracts: If you have visually significant cataracts, combining cataract surgery with MIGS can address both problems efficiently.

Overall Eye Health: Other eye conditions, previous trauma, or inflammation may influence which procedure is safer and more effective.

Your Lifestyle and Recovery Needs: Your work demands, support system at home, and ability to comply with post-operative care all factor into the decision.

This is a personalised decision that you and your ophthalmologist will make together based on a comprehensive evaluation of your individual situation.

Can MIGS Be Combined with Cataract Surgery?

One of the most significant advantages of MIGS is that it can often be performed at the same time as cataract surgery. This combined approach treats both conditions in a single procedure, with one recovery period instead of two.

For patients with both cataracts and glaucoma—a common combination as both conditions increase with age—this is remarkably convenient. You address your cloudy lens and elevated eye pressure simultaneously, potentially reducing your dependence on glaucoma medications whilst improving your vision.

The combined procedure adds minimal time to cataract surgery (typically 10-15 minutes) and doesn’t significantly increase the recovery burden. Most patients find this approach highly appealing compared to staging two separate surgeries.

Not all glaucoma patients are candidates for combined surgery, and not all MIGS devices are suitable for combination procedures. Your ophthalmologist will assess whether this option is right for you based on the severity of both your cataract and glaucoma.

Frequently Asked Questions

Q: Is MIGS as effective as traditional glaucoma surgery?

MIGS is highly effective for mild to moderate glaucoma, typically lowering pressure by 20-30%. Traditional surgery achieves greater pressure reduction (30-50%+) and is more effective for advanced glaucoma. The “best” option depends on how much pressure lowering you need—MIGS offers excellent results with lower risk for appropriate candidates.

Q: How long does MIGS surgery take?

Most MIGS procedures take 15-30 minutes when performed alone, or add just 10-15 minutes to cataract surgery when combined. Traditional glaucoma surgery typically takes 45-90 minutes depending on the specific procedure and complexity.

Q: Will I still need glaucoma drops after MIGS?

Many patients can reduce their glaucoma medications after MIGS, and some can stop drops entirely. However, MIGS is often considered a way to reduce medication burden rather than eliminate it completely. Traditional surgery has a higher likelihood of eliminating the need for drops, though some patients still require medication for optimal control.

Q: What are the risks of MIGS vs traditional surgery?

MIGS has a lower risk profile overall, with uncommon serious complications. Risks include temporary pressure elevation, bleeding, inflammation, and rarely, device malposition. Traditional surgery carries higher risks including infection, excessive pressure lowering (hypotony), bleeding, and cataract formation (if you haven’t already had cataract surgery). However, with an experienced surgeon, serious complications from either procedure are uncommon.

Q: Can MIGS be repeated if needed?

Yes, one advantage of MIGS is that it doesn’t typically prevent future procedures. If additional pressure lowering is needed, you may be able to have another MIGS procedure or progress to traditional surgery. MIGS doesn’t “burn bridges” for future treatment options.

Q: How do I know which surgery I need?

The decision requires a comprehensive evaluation by a glaucoma specialist who will assess your glaucoma severity, current pressure, medication regimen, overall eye health, and individual circumstances. Discussing your priorities, concerns, and lifestyle needs with your surgeon helps ensure the chosen approach aligns with your goals.

Making Your Decision

Both MIGS and traditional glaucoma surgery are proven, effective approaches to managing glaucoma and preserving vision. The key is matching the right procedure to your specific clinical situation.

MIGS offers a less invasive path with faster recovery and lower risk, making it ideal for patients with mild to moderate glaucoma, especially when combined with cataract surgery. Traditional surgery remains the gold standard for achieving maximum pressure reduction in more advanced cases or when other treatments have been insufficient.

If you’re considering glaucoma surgery, Dr Nathan Kerr can help you understand which option is right for your specific situation. With expertise in both minimally invasive and traditional glaucoma surgical techniques, and involvement in clinical research through the International Glaucoma Surgery Registry, Dr Kerr provides evidence-based, personalised care for Melbourne patients.

Ready to discuss your glaucoma treatment options? Book a consultation at Eye Surgery Associates to learn which approach is best for preserving your vision.

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For urgent concerns about your eye pressure or vision, please call our clinic directly.

About the Author

Dr Nathan Kerr is a specialist ophthalmologist and glaucoma surgeon practising in Melbourne. He specialises in advanced cataract surgery and minimally invasive glaucoma surgery (MIGS), with a focus on reducing medication dependence and preserving vision through the latest surgical techniques. Dr Kerr is actively involved in clinical research through the International Glaucoma Surgery Registry, ensuring his patients benefit from the most current evidence-based practices.

Medical Disclaimer: This information is for educational purposes only and does not replace professional medical advice. Glaucoma treatment decisions should be made in consultation with your ophthalmologist based on your individual clinical situation.