For post-operative instructions, click here
Glaucoma surgery is less commonly performed nowadays, owing to the effectiveness of drop medication such as prostaglandin analogues. If, however, visual fields are progressively deteriorating despite medication, then surgery is generally the preferred option. An alternative is laser, but the effect of laser trabeculoplasty are less effective in the longer term.
The gold standard surgical treatment for glaucoma is trabeculectomy. This is often performed using anti-scarring agents at the time of surgery (for example, mitomycin C).
Explanation of trabeculectomy
1. First, the conjunctiva is opened in a small section under the eyelid. The conjunctiva is the white outer skin lining the front of the eye surrounding the cornea.
2. Then, a small square partial thickness flap is created in the sclera - the main structural coat of the eye. This flap is lifted up and folded forward, then a tiny full thickness cut is made to allow the fluid to drain out of the eye. A small section of iris is removed to prevent the iris blocking the drainage channel created.
3. The flap is sutured back with nylon sutures, generally with some releasable sutures to allow postoperative control of eye pressure.
4. The conjunctiva is sutured back in place with sutures buried under the surface.
Glaucoma surgery is very effective at controlling eye pressure. Generally, at one year after surgery, most patients will no longer be taking any glaucoma medication. However, surgery may occasionally need to be repeated if eye pressure becomes elevated despite reintroduction of drops.
An anti-scarring medication - 5-fluorouracil - is often given postoperatively to supplement the antiscarring effect of agents given during surgery. This is not generally required, but if the drainage bleb appears 'encysted' then this is often used to lower the pressure with a revision procedure - perhaps in 5% of cases having glaucoma surgery.
Are there any Complications with a Trabeculectomy?
Serious risks with a Trabeculectomy procedure are uncommon. The most significant risks are infection (<1% risk) and bleeding (<0.1%). Both of these conditions may affect sight, but fortunately are rare problems. After glaucoma surgery, it is important to be careful with hand hygiene - ie to wash hands before any drop application. Patients taking aspirin - depending on the reason - may be advised to stop taking such medication 2 weeks prior to surgery to minimise risks of bleeding.
Ahmed valve surgery
Ahmed valves are used for uncontrolled glaucoma, where trabeculectomy is less likely to be effective. For details on Ahmed valves, please click this link.
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