What is bleb needling?
During your glaucoma surgery (Trabeculectomy) a small opening is made under the upper eyelid, to let the fluid escape and lower the pressure.
The fluid that flows out of your eye forms a small cyst, called a bleb, which is under the conjunctiva, the thin transparent layer that covers the white of your eye.
Drainage surgery for glaucoma (Trabeculectomy) may fail to bring the pressure low enough or may scar and fail. This can occur shortly after the operation is performed or at any time. In some cases bleb needling may be the next step to restore drainage and achieve a lower eye pressure.
The needling is generally considered a safe outpatient procedure.The procedure is usually done under local anaesthetic .This will be discussed with you.
The local anaesthetic involves putting in drops that numb the front surface of your eye followed by an injection in the skin around the eye, which will make the area around your eye go numb. This may last for a few hours and can affect your vision at the time.
The needling involves breaking down the wall of the scar tissue using a fine needle. This will help to improve the drainage of the watery fluid called aqueous humour. An anti-scarring drug is then injected to try to prevent further scar formation.
At the end of the procedure, an injection of antibiotic and steroid may be given to reduce the risk of infection and inflammation.
- The most sight threatening problems that can occur are bleeding inside the eye, or a serious infection. Antibiotic drops are given to help to prevent infection. These complications are rare and occur in less than 1 in 1000 operations.
- The pressure in the eye may rarely go too low after the operation and require further intervention.
- The anti-scarring agent may cause the wound to leak or may change the surface of the cornea (the clear window at the front of your eye). This recovers in almost all cases.
- After the needling you may experience some slight discomfort. You may wish to take a painkiller, for example Paracetamol, to relieve this discomfort. If you are already taking painkillers for a different condition continue with these, but do not take both.
These are the same risks that are present when undergoing the glaucoma drainage operation (Trabeculectomy).
The procedure works in more than half the eyes operated on to restore and improve drainage. It is most successful if the trabeculectomy operation has been performed recently.