Goniotomy

What is Goniotomy?
Goniotomy is a minimally invasive glaucoma surgery (MIGS) that involves making a small incision in the trabecular meshwork to improve the outflow of aqueous humor and reduce intraocular pressure (IOP). Performed under direct gonioscopic visualization with a surgical microscope, it is commonly used in both congenital and early-stage open-angle glaucoma. It can be performed on its own or combined with other procedures such as cataract surgery or implantation of devices like the iStent or OMNI.

How does Goniotomy work?
During goniotomy, the surgeon uses a gonio lens to visualize the anterior chamber angle and then makes a small incision in the trabecular meshwork—the main drainage tissue of the eye—using specialized tools like the Kahook Dual Blade (KDB) or Sinskey hook. This incision helps bypass the resistance in the drainage system, allowing aqueous humor to flow more freely and thereby lowering IOP. Because it preserves the eye’s natural anatomy, goniotomy is associated with a favorable safety profile.

Who is a good candidate?

• Infants or children with congenital glaucoma

• Adults with mild to moderate open-angle glaucoma

• Patients with pigmentary or pseudoexfoliative glaucoma

• Those not well-controlled on medications but not yet requiring more invasive surgery

• Individuals undergoing cataract surgery who need IOP-lowering benefits
  Not recommended for patients with angle-closure glaucoma, extensive angle scarring, or failed angle-based procedures.

Steps During the Procedure

1. Local anesthesia and mild sedation are administered

2. A surgical microscope and gonio lens are used to visualize the drainage angle

3. A small incision is made in the trabecular meshwork using a KDB or similar device

4. Fluid outflow improves through the newly created opening

5. Antibiotics and anti-inflammatory drops are applied

What to Expect Before, During, and After

• Before: Eye exam, imaging, and pre-op instructions (such as no food or drink)

• During: Outpatient setting; takes approximately 10–15 minutes

• After: Eye drops (antibiotics and steroids) for 1–2 weeks; vision may be temporarily blurry; return to normal activity within a few days to a week. Full recovery in 2–6 weeks.

Is Goniotomy Safe?
Yes, goniotomy is considered a very safe procedure.

• Lower complication rates than traditional filtering surgeries

• Minimal trauma and no implant left in the eye

• Especially safe for pediatric and early-stage adult cases

• May be less effective in advanced glaucoma requiring more aggressive pressure lowering

Complications
While rare, possible risks include:

• Hyphema (blood in the anterior chamber)

• Transient spikes in IOP

• Inflammation or infection

• Scarring of the trabecular meshwork

• Incomplete pressure reduction requiring further treatment

Insurance and Coverage

• Typically covered by Medicare and most private insurers when medically necessary

• Common indications: primary open-angle glaucoma, ocular hypertension, congenital glaucoma

• CPT code: 65820

• If combined with cataract surgery and a device like KDB, reimbursement may vary—preauthorization is recommended

Advantages

• Preserves natural eye anatomy

• Lower risk of complications

• Can be combined with other MIGS or cataract surgery

• Good safety profile in children and adults