Trabeculectomy The process, cost and FAQs

What is trabeculectomy?

It is a filtration operation to create a new outflow channel for the aqueous fluid to drain out of the eye and ultimately reduce the eye pressure. The newly formed outflow channel can be seen in the upper part of the eye and is usually covered by the eyelid. It is known as the bleb. In most cases (95%), it achieves the target eye pressure without the use of topical medication.

What to expect before and during trabeculectomy

Before the surgery, your consultant may commence you on anti-inflammatory drops to “maximise” the surface of the eye and ultimately improve the success of the operation.

During the surgery, the eye will be anaesthetised with either a local anaesthetic injection or general anaesthetics. The surgery itself can take anything from 45minutes to 1 hour during which the outer covering of the eye (conjunctiva) is opened and a partial thickness flap door is created in the white part of the eye (sclera). A passageway is then formed between the anterior chamber and the newly formed drainage channel for the aqueous fluid to flow through. The flap is then secured with “releasable sutures” that can later be used to tweak the eye pressure, and the conjunctival opening is sutured.

At the end of the surgery, you will be given an antibiotic and anti-inflammatory injection to prevent any infection or scarring. The eye is then normally covered with a cotton pad and a protective shield.

What to expect after trabeculectomy

After the operation you will be asked to avoid any rubbing of the eye, any heavy lifting, strenuous exercise, bending down, getting water into the eye or straining in any form as this could cause the pressure in the eye to rise. You will be told to stop any previous glaucoma drops you were using and given intensive topical steroids (8 per day) and antibiotics (4 per day) to use for 4-6 weeks.

The vision is usually blurred for the first few days following the trabeculectomy operation but as long as it is not worsening, this is completely normal. The eye will feel uncomfortable due to the sutures but not painful and again this tends to subside in the first week. The eye will look red and there may be some mild watering or clear discharge in the first 1-2 weeks.  You will be having regular visits and an intensive post operative drop regime for the first 4 weeks. Once the initial period passes, the vision will return to the pre-operative level, the pressure will be within target and you will come off all topical medication in the operated eye.

You will need a review on day 1, week 1, week 2, week 3-4 and then, depending on how well the bleb is healing, week 6. At this point, the topical steroids drops will be tailored over the following 2-4 weeks and you will be seen once all drop courses have been completed.

Possible complications of trabeculectomy

The success rate of trabeculectomy is 95%. It is a well established surgery which has been refined further and today is considered the gold standard filtration surgery in glaucoma nationwide. But, as with every operation, there is always a small risk of complications, most of which are mild and temporary. These include:

• Infection (under 1%)
• Uncontrolled Inflammation (under 1%)
• Over drainage causing very low pressures (also known as hypotony) (5%)
• Failure (5%)
• Revision surgery (under 5%)
• Lens opacity in phakic patients (50% in 2-4 years)
• Permanent irreversible reduction of vision/loss of sight (<1%)