Glaucoma surgery

If despite treatment with eyedrops the IOP remains high and there is evidence of progressive visual field loss glaucoma surgery may be needed to prevent further damage to your vision. This operation is called a trabeculectomy and can be performed alone or it can be combined with a cataract removal.

Before the operation:

Once your specialist has decided that you need a trabeculectomy the surgery is likely to be carried out fairly quickly. It is important to continue taking your normal glaucoma drops during this period.

How is the operation done?

In the anaesthetic room

Like cataract surgery the vast majority of trabeculectomies are carried out under a local anaesthetic. Local anaesthetic is injected around the eye – this stings a little. A pad or small balloon is then placed over the eye for 5-10 minutes. Once the local anaesthetic has taken effect you will not be able to see or feel what is happening, nor will you be able to move the eye or blink. During the operation you may occasionally see bright or coloured lights and you may be aware of the surgeons hands resting on your forehead and/or face.

In the operating theatre

• you will be lying down and the eye will be cleaned with an iodine solution
• a sterile plastic drape is placed over your eye and then passes above your face like an open tent. A tube blowing fresh air or oxygen will be placed under the drape allowing you to breathe completely normally.
• The operation is performed under a microscope and involves making a special type of small trap door in the sclera (white outer coat of the eye). A small segment of the iris is then removed to prevent it floating up and blocking the trapdoor. The scleral trapdoor is then closed with microscopically fine stitches so that the fluid in the eye may drain slowly out of the eye so reducing the pressure. Your surgeon may use a specialized technique which allows the tension in these small stitches to be adjusted after the surgery or for them to be removed altogether. This means that the drainage of fluid can be improved a simple maneuver carried out in the outpatient clinic.
• Your surgeon may also use a special medicine, applied to the eye for a few minutes by a very small sponge, to slow down or prevent subsequent healing and sealing up of the trapdoor. Useful medicines include 5FU and mitomycin C.
• The drapdoor is then covered by the conjunctiva, the clear tissue on the surface of the sclera, and this is carefully stitched in position.
• The leaking fluid collects underneath the conjunctiva and lifts it very slightly to form what is called a “bleb”. This may sometimes look like a small cyst
• At the end of the operation the eye is given a small dose of antibiotic and a medicine to reduce inflammation. The eye is ten covered with a shield or pad.

After the operation

Your operation will often be undertaken as an out-patient. In most cases you will need to be seen by your surgeon the following day.

The weeks following surgery are very important and careful management is required during this time to maximize the chances of a successful outcome. You need to be aware, therefore, that there is a required commitment to attending the outpatient clinic regularly during this period.

Dos and Don’ts after the operation:

Do

• use the drops as instructed
• continue with normal light daily activities
• take things easy
• avoid splashing soap, water or anything else into the eye
• wash your hair in the shower with the eye kept shut, or by leaning back at a basin
• be aware that the vision is often very blurred for a number of weeks after the operation. Wearing your old glasses may or may not improve this blurred vision.
• Expect to be off work for 2 weeks

Don’t

• carry out strenuous exercise
• rub or press on the eye. This is very important.
• miss any outpatient appointments
• drive unless, or until, you are told it is safe to do so