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Minimally Invasive Glaucoma Surgery (MIGS)

Normal eyes VS Eyes with Glaucoma

Glaucoma causes the optic nerve to be damaged due to elevated eye pressure. The only effective treatment for glaucoma is to lower the eye pressure.

Conventional glaucoma surgeries, such as trabeculectomy and tube implant surgery, are often effective in lowering eye pressure but may have rare and potentially serious complications. 

Introducing Minimally Invasive Glaucoma Surgery (MIGS)

Minimally Invasive Glaucoma Surgery, or MIGS for short, has emerged in recent years as a new type of glaucoma surgery.  

On the whole, MIGS procedures are safer than conventional glaucoma surgery with much less risk of significant complications. Since MIGS is less invasive, patients can recover much faster and return to their normal activities sooner. 

MIGS procedures can also improve a patient’s quality of life by reducing the number of glaucoma eye drops required which can cause side effects such as redness, itchiness, and discomfort.

Types of Minimally Invasive Glaucoma Surgery Procedures

MIGS can be broadly divided into procedures that drain fluid into internal pathways and those which drain fluid directly out of the eye.

MIGS Procedures Which Drain Internally 

Trabecular bypass implants bypass the trabecular meshwork at the angle, the structure which impedes fluid drainage the most in glaucoma. By bypassing the trabecular meshwork, the fluid can drain much better internally into the blood vessels.

The trabecular bypass implants are very safe, and can be implanted at the same time as routine cataract surgery, even if the glaucoma is well controlled with eye drops. The additional MIGS implant does not significantly increase the risks of the procedure compared with cataract surgery alone. 

Combining cataract surgery with trabecular bypass MIGS essentially kills two birds with one stone: improving the vision by cataract removal, and improving glaucoma control with less eye drops. However, these devices are generally less effective than conventional glaucoma surgery, so they are more appropriate for patients with mild to moderate glaucoma who require less eye drops.

MIGS Procedures Which Drain Externally

MIGS devices that drain externally allow the fluid to flow out of the eye into a reservoir called the bleb. They are potentially capable of achieving lower eye pressure, hence are appropriate for more advanced glaucoma than trabecular bypass MIGS. However, they are also associated with more risks compared with trabecular bypass MIGS, though they are likely still safer than conventional glaucoma surgery such as trabeculectomy.

Benefits of Minimally Invasive Glaucoma Surgery

  • High safety profile
  • Minimal disruption to eye structures
  • Effective in lowering eye pressure
  • Reduces or eliminates the need for glaucoma medications
  • Rapid recovery with minimal downtime

Am I a suitable candidate for MIGS?

You are a suitable candidate for MIGS if you:

  • Have mild to moderate glaucoma 
  • Require one to two glaucoma eyedrops
  • Are intolerant or non-compliant with glaucoma eyedrops

MIGS Devices



Hydrus Microstent

iStent inject W

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    Dr Chelvin Sng of Chelvin Sng eye center

    Dr Chelvin Sng

    Adjunct Associate Professor
    Senior Consultant Ophthalmologist
    ✓ 4 Gold Medals (Specialist Accreditation Examination)
    ✓ "Top 50 Rising Stars” (2017), “Top 100 Female Ophthalmologists” (2021)
    and "Top 100 Ophthalmologists" (2022)
    ⋆ Global Ophthalmologist Power List (voted by peers worldwide)
    ✓ Cambridge University Graduate with Triple First Class Honours and Distinctions


    38 Irrawaddy Road Mt Elizabeth Novena Specialist Centre, #06-25, Singapore 329563

    Operating Hours

    Mon - Fri: 9am - 5pm
    Saturday: 9am - 1pm
    Sunday / PH: Closed