Glaucoma, or the deterioration of the optic nerve, progresses over many years. Currently, the only proven treatment for glaucoma involves lowering internal eye pressure to prevent or delay further damage. Depending on what stage of the disease you’re diagnosed with, treatment usually begins with medicated eye drops and will only proceed to surgery if necessary. If you do need glaucoma surgery, here are the different types of surgery available and what the pros and cons of each are.*

What types of glaucoma surgery are there?

The most common glaucoma surgeries include:

• Trabeculectomy (surgical removal of part of the eye’s drainage system for better flow) 
• Tube shunt (drainage device implantation to redirect flow from the obstruction)
• Cyclophotocoagulation (type of laser surgery to relieve intraocular eye pressure (IOP))

What are the risks of glaucoma surgery?

Though the risks of glaucoma surgery are few, and their occurrence rare, the following possibilities should be discussed with your doctor before any type of glaucoma surgery.

• Vision loss: Expect some temporary vision loss immediately after surgery as your eyes are healing. Permanent vision loss is a risk of any eye surgery, but it is extremely rare.
• Bleeding in the eye: Internal bleeding in the eye can be a serious complication that threatens your long-term vision. Let your ophthalmologist know if you are on blood thinners, as you may need to discontinue use before surgery.
• Infection: Despite the application of antibiotics and best efforts to maintain a sterile environment, an infection can sometimes occur weeks, months, or years following surgery. Contact your doctor immediately if you experience post-surgery redness, pain, or excessive tearing. Most infections can be treated with antibiotic drops if caught early.
• Low eye pressure (hypotony): Glaucoma surgery can sometimes provoke temporary low IOP, which may cause you to see shadows in your peripheral vision. 
• Scarring: Scar tissue may form during the healing process, which can cause IOP to increase and negate the benefits of surgery. If this occurs, you may need to restart your glaucoma medications or undergo an additional operation.
• Cataracts: Glaucoma surgery can accelerate cataract formation. In some cases, the two surgeries may be combined for people with both diseases.

New technologies

A group of newer procedures, called minimally-invasive glaucoma surgery (MIGS), are increasingly growing in popularity. Frequently, a MIGS is combined with cataract surgery to lower eye pressure in patients with early- to moderate-stage glaucoma.

MIGS involves limited manipulation of the sclera (thick white wall of the eye) and conjunctiva (transparent outermost layer)—making it safer than traditional glaucoma surgeries. The improved safety features, however, often yield more modest results. Thus, MIGS may not achieve the intended reduction in eye pressure for patients with more advanced glaucoma.

*Ou, Y. (2018, Apr. 23). Glaucoma Surgery Series: The Risks and Benefits of Glaucoma Surgery. BrightFocus Foundation. https://www.brightfocus.org/glaucoma/article/glaucoma-surgery-series-risks-and-benefits-glaucoma-surgery

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