Overview

A viscocanalostomy is a type of glaucoma surgery that reduces the pressure in your eye.

During the surgery an opening is made through the white of the eye to find the trabecular meshwork (the area where the fluid that is produced inside the eye is meant to drain through). Problems in this area are the most common reason why people develop high eye pressure. This area is then cleared so more fluid can flow through, reducing eye pressure. The surgery is done on an area of the eye normally hidden under the upper eyelid.

Sometimes this surgery is combined with cataract surgery.

Your eye surgeon has recommended this surgery because:

• medical treatments, eye drops, or laser, have not controlled your condition properly 
• eye drop treatment is unsuitable

Benefits of a viscocanalostomy

This operation aims to preserve the sight that you have. It will not restore any sight you have lost, or improve your sight, but aims to reduce the risk of further loss of vision.

If cataract surgery is done at the same time, your vision may improve as a result of that part of the surgery. 

Risks of a viscocanalostomy

This type of glaucoma surgery may be preferred to other glaucoma surgery such as a trabeculectomy, as there is less risk of complications, especially in certain patients. This includes patients who are short-sighted, or have conditions like uveitis.

As with all types of surgery, there are still some risks, and it's important you are aware of them.

Minor bleeding at the front of the eye is common and usually clears all on its own.

Very rare risks include severe infection, bleeding and other problems at the back of the eye. 

There is a very small risk of loss of vision after these procedures. In extremely rare cases, this could lead to blindness, particularly in advanced glaucoma.

Sometimes it's not possible to access, clear, or dilate (enlarge) the drain enough, for example, due to scarring. There might be more blockages in the main drainage canal which cannot be cleared. In both situations, if viscocanalostomy surgery does not reduce the eye pressure enough, other surgery might be required.

Sometimes the effect of the surgery can wear off if the drainage area becomes blocked again and the eye pressure starts to increase again. If this happens, eye drops can be re-introduced and more glaucoma surgery can be done, if needed.

Other treatment options

An alternative to viscocanalostomy surgery is another type of surgery called a trabeculectomy. This can result in a lower eye pressure after surgery, however has a higher risk of complications.  A trabeculectomy also needs more intensive follow-up, and use of drops immediately after surgery.

Eye drops

After surgery, you will usually stop using any existing glaucoma drops to the operated eye. Many patients can stop using eye drops for many years. Some patients, especially those needing low eye pressures, will need to restart some glaucoma eye drops at some time after surgery.

Although you should stop your glaucoma drops in the operated eye after the surgery, we will give you some anti-inflammatory and antibiotic eye-drops to use for about a month after the 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.