Glaucoma surgery (trabeculectomy)

Trabeculectomy is the most common type of surgery used to treat glaucoma.

Glaucoma is a condition where there is damage to the optic nerve, which carries visual signals from the eye to the brain. Damage is usually caused by a build-up of fluid (aqueous humour) within the eye. This causes the pressure inside the eye to rise. If left untreated, glaucoma can lead to severe loss of vision or even blindness.

What does glaucoma surgery involve?

During glaucoma surgery the surgeon will make a small hole in the sclera (the white part of the eye), covered by a tiny trap-door which fluid can drain through. Fluid drains into a small bleb (blister) on the surface of the eye, which is usually hidden under the eyelid.

During the procedure a drug, mitomycin C, may be applied to reduce scarring after the operation. It helps to keep fluid draining from the eye.

What to expect?

Glaucoma surgery may be carried out under either local anaesthetic or general anaesthetic. Most surgery is performed as a day case, so you would usually return home on the same day. The operation will generally last for less than an hour.

Risks of glaucoma surgery

Surgery is usually a safe procedure and it’s effective in reducing the pressure within the eye. Occasionally the pressure in the eye may drop too low, so further surgery may be needed. This is the most common complication of trabeculectomy. Other complications are rare, but may include:

• infection
• bleeding
• blurring or loss of vision
• discomfort
• collection of fluid under the retina
• double vision.

Your consultant will discuss the potential complications with you in more detail.

Alternative treatments

Eye drops are the main non-surgical treatment for glaucoma. If they’re not effective, there are other options apart from trabeculectomy. These include laser treatment and many other types of newer glaucoma surgeries, collectively known as MIGS (minimally invasive glaucoma surgeries), which can be used to reduce the pressure in your eyes. Your consultant will be able to discuss these alternatives with you and advise on the most appropriate course of action.