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Minimally Invasive Glaucoma Surgery

What is Minimally Invasive Glaucoma Surgery (MIGS)?

Traditional glaucoma surgery creates an incision on the outside of the eye and a new path for fluid to drain from the eye. This surgery results in the formation of a drainage site on the outside of your eye under your eyelid.

In contrast, minimally invasive glaucoma surgeries (MIGS) are performed through a tiny incision in the cornea. The incision is the same size as what is made during cataract surgery. MIGS targets the natural drainage system of the eye found in the “angle” between the iris and the cornea.The goal of MIGS is to reduce your eye pressure with less risks, a shortened recovery time, and fewer follow up visits.

Even though MIGS improves the fluid drainage and lowers eye pressure, you still might need to use glaucoma medications to reach your ideal eye pressure. Often, patients require fewer glaucoma medications following MIGS.

Who is a good candidate for MIGS?

  1. If you have glaucoma and cataracts, MIGS is often combined with cataract surgery because the incisions that are created at the time of cataract surgery can be used to perform MIGS.
  2. If you need lower eye pressure or develop side effects to your glaucoma medications, especially if you have not already had traditional glaucoma surgery, MIGS is a good first option.
  3. If you are on blood thinners, traditional glaucoma surgery can cause bleeding. With fewer incisions in MIGS, there is less bleeding.
  4. If frequent postoperative visits are difficult for you, MIGS usually requires fewer postoperative visits than traditional glaucoma surgery.

What types of MIGS are offered by our surgeons?

1. Goniotomy

A specialized instrument, such as the Kahook Dual Blade®, removes a section of the eye’s dysfunctional drainage system which helps improve outflow of fluid, thereby lowering eye pressure.

Goniotomy Kahook Dual Blade

2. iStent® Trabecular Micro-bypass

A small titanium device is implanted in the ocular drainage system to increase aqueous humor outflow through the system and lower eye pressure. The iStent® is implanted at the same time as cataract surgery. It is the smallest implantable medical device available. Once it is inserted, you will not be able to feel or see the device. It is MRI safe.

iStent® Trabecular Micro-bypass

3. ABiC™ (Ab-Interno Canaloplasty)

A micro-catheter is threaded through the eye’s natural drainage system to enlarge and relieve obstruction in the drain of your eye.

ABiC™ Ab-Interno Canaloplasty

4. GATT (Gonio-assisted Transluminal Trabeculotomy)

Similar to ABiC™, the procedure passes a catheter through the drainage system. The catheter is then used to unroof the drainage system to help increase outflow of aqueous humor to lower eye pressure.

The type of procedure chosen is dependent on the anatomy of your eye, your risk for bleeding, previous eye surgeries, and surgeon preference.

Surgery and Postoperative Care

Often MIGS is combined with cataract surgery. The surgery is performed in the operating room with topical anesthesia and IV sedation. After surgery, eye drops are prescribed to prevent infection and reduce inflammation. For several weeks following surgery, your ophthalmologist will examine you frequently. There is often a small amount of bleeding inside the eye that can blur vision but this clears quickly. During this time it is also common for your eye pressure to fluctuate.

Why do some people still need to have traditional glaucoma surgery?

If you have severe glaucoma or ongoing vision loss despite normal eye pressures, you may need eye pressures lower than what MIGS can achieve. Your surgeon will make that determination and recommend the procedure that is right for you.


MIGS increases the flow of fluid through the eye’s natural drainage system, lowering eye pressure. These surgeries are performed through small incisions, require less recovery time and fewer follow up visits compared to traditional glaucoma surgery. Your surgeon will talk to you to determine if you are a good candidate for MIGS and which type of MIGS might be best for you.

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