Overview

The Preserflo MicroShunt is a small (about 8mm long) tube, which is inserted into the eye during surgery. It helps reduce eye pressure, or the need for glaucoma medicines. 

Benefits of having the Preserflo MicroShunt 

Your eye surgeon has recommended the surgery because:

• medical treatments, eye drops, or laser, have not lowered your eye pressure enough 
• you have not been able to tolerate eye drop treatment

The aim of the operation is to lower the pressure in the eye and help preserve the sight you currently have. It is important to understand that this procedure will not improve your vision or restore sight that has already been lost. 

Risks of having Preserflo MicroShunt surgery 

This type of glaucoma surgery may be preferred to other procedures because there is a lower overall risk of complications. However, as with any operation, there are risks that you should be aware of.

• Minimal bleeding in the front of the eye, which usually clears on its own.
• Eye pressure becoming too low, which very rarely can lead to bleeding at the back of the eye
• The front of the eye becoming shallow, which may require a small injection of gel (viscoelastic) to restore its shape
• Blockage of the MicroShunt, which may need further surgery or laser treatment to clear it. Very rarely the MicroShunt might need to be removed if these blockages cannot be cleared.

Blurred vision is common after surgery and is often temporary. This can last for several weeks. Vision may change due to how the eye focusses, and updating your glasses may help.

In extremely rare cases, severe loss of vision can occur, particularly in eyes with advanced glaucoma.

Infection is a risk after any eye surgery. Serious infections have not been reported following Preserflo implantation, but they are a recognised risk with similar glaucoma procedures. 

Preserflo surgery can fail over time, usually due to excessive scarring. This can cause eye pressure to rise again. Treatment may include anti‑inflammatory drops, further surgery to remove scarring, or a different procedure to reduce eye pressure.

There is a small risk that the tube may become exposed. This can increase the risk of infection or low eye pressure and may need treatment with additional drops or surgery. 

Because the MicroShunt is a foreign material placed in the front part of the eye, it may cause loss of corneal cells. This can lead to corneal swelling and, very rarely, may require surgery to repair the cornea.

Drooping of the eyelid can occur after surgery. This often improves as the eye heals, but further surgery may sometimes be needed to correct it.

Other treatment options

A trabeculectomy is another surgical option and has been shown to achieve similar reductions in eye pressure. However, it carries a higher risk of complications and usually requires more intensive follow‑up.

As Preserflo MicroShunt surgery is newer, long‑term results and direct comparisons with trabeculectomy are still being studied.

Eye drops after surgery

After surgery, you will usually be asked to stop all glaucoma eye drops in the operated eye.

• some people can stop using glaucoma drops for many years
• others, especially those who need very low eye pressure, may need to restart drops at a later stage

Please continue using any glaucoma drops for the eye that has not been operated on.

You will be given new eye drops to use in the operated eye for about one month after surgery.

Giving your permission (consent)

We want to involve you in decisions about your care and treatment. If you decide to have the procedure or treatment, we will ask you to sign a consent form. This says that you understand what is involved and agree to have the treatment.

Read more about our consent process.