How glaucoma surgery works

Glaucoma surgery improves the drainage of fluid from the eye, lowering eye pressure.

There are different types of glaucoma surgery and it is important that we discuss the various options with you before you undergo treatment. The most common glaucoma surgery is trabeculectomy.

What is trabeculectomy?

The operation involves forming a small channel through the white part of the eye. This channel will allow fluid (aqueous) – made naturally in the eye – to drain away. The drainage site is under the upper eyelid and cannot be seen, and once settled, should not cause you discomfort. The fluid will drain from the channel and be absorbed by conjunctival vessels in the eye.

Patients having this surgery can have it under a general or local anaesthetic.

Advantages and disadvantages of glaucoma surgery

Advantages

• Surgery is often the most effective way to lower eye pressure significantly
• Surgery can be performed when eye drops or laser have not sufficiently controlled the eye pressure
• After surgery, patients often no longer need to use daily glaucoma drops

Disadvantages

• Like any surgical procedure, glaucoma surgery carries an element of risk

Glaucoma surgery risks

Glaucoma surgery, like any other operation, carries with it the risk of complication. However, fortunately, serious risks such as the vision becoming worse or losing vision completely (blindness) are uncommon.

Glaucoma surgery options and alternatives

Eye drops

Eye drops can be used to lower eye pressure. These medications work by reducing fluid production inside the eye or helping fluid drain from the eye. Glaucoma medications must be taken regularly each day to work effectively. Some patients may require more than one type of eye drop. If treatment with eye drops fails to control the pressure in your eye, or you experience side effects from them in the eye, laser treatment and/or an operation may be required.

Laser treatments

Laser treatment uses light to help fluid drain from the eye or eliminate the fluid blockage. Medications are used to numb the eye before treatment so it is usually little or no pain. Most lasers take only a few minutes to perform. The type of laser that is right for you depends on your type of glaucoma.

Common types of laser include:

• Laser trabeculoplasty
• Laser iridoplasty
• Laser iridotomy
• Diode laser

Glaucoma surgery steps

Step one: We’ll perform a procedure with the intention of lowering your eye pressure

Step two: You’ll be asked to use eye drops after your surgery

Step three: We’ll regularly see each other after your surgery to ensure that your eye is responding well to the procedure

Glaucoma surgery results

Will the operation improve my sight?

Unfortunately, the operation cannot bring any sight that has been lost. After the operation, your sight may be initially blurred and seem worse. This is usually only temporary as your eye will need time to heal and settle down following surgery. This can take up to 6-8 weeks in total.

How successful is the operation?

Evidence shows that surgery is most effective at lowering eye pressure, and the lower the eye pressure, the lower the risk of progressive visual loss from glaucoma. Following surgery, in up to 80% of cases, no further treatment is necessary. In 10-15% of cases, drops to reduce pressure will still be needed. In 5-10% of cases, further treatment or surgery may be necessary.

There is a small risk of bleeding in the eye at the time of surgery which usually clears gradually. There is also a small risk of over drainage, so the pressure is too low after surgery. This usually settles but may need extra treatment. There is also a rare risk of late infection. The rate of development of a cataract may become accelerated after glaucoma surgery, and this may require lens surgery to improve your vision.

How long will I be in the hospital after the operation?

Most patients can go home the same day of surgery, assuming they have good vision in the other eye or have someone with them that evening. Patients can choose to stay overnight if this may be difficult.