A trabeculectomy is drainage surgery used in the management of glaucoma.
The term Trabeculectomy refers to making a hole in the drainage area of the eye, to allow fluid from inside the eye to be released, thereby lowering the intraocular pressure.
Most glaucoma is treated by medical therapy in the form of eye drops. In most cases the eye pressure is sufficiently lowered by the eye drops to reduce the risk of vision loss from glaucoma. In some cases the pressure lowering is not sufficient and requires further treatment. The current options are tablets, laser or drainage surgery. Generally, tablets are only used in the short-term for pressure control as they are associated with side-effects. Laser, also, does not generally have a long-term effect and is utilised mainly if surgery is not safely possible.
Trabeculectomy is performed as Day Surgery and does not require overnight admission. It is necessary to stop aspirin, warfarin, anti-inflammatories, fish oil or any other blood thinning medications 7 days prior to surgery. Local anaesthesia with sedation is preferred as it is safer for the patient and provides more rapid recovery. General anaesthesia can be performed in certain patient indications. The procedure takes one to one and a half hours, depending on the complexity of the glaucoma.
The aim of the surgery is to create a one-way flap valve from the inside of the eye to under the conjunctiva of the eye. The fluid subsequently passes from this small reservoir (bleb) back into the blood vessels of the conjunctiva. It does not result in more tearing from the eye as there is no external drainage of the fluid. During the operation anti-scarring agents such as Mitomycin C are used to optimise the long-term drainage of the fluid from the eye.
A pad/shield is worn on the first night. As the eye can be uncomfortable due to the nature of the surgery, it is advised to rest and take oral analgesia if required. It is advised to sleep slightly elevated on two to three pillows during the first night to prevent overdrainage of fluid. No eye drops need to be administered on the first night.
The next day your eye will be reviewed. The eye pad will be removed, the eye cleaned and the trabeculectomy site checked. If you bring your post-operative eye drops, the first dose will be put in for you.
The first 3-4 weeks are critical in establishing the flow through the trabeculectomy site. We may need to see you twice a week during that period in order regulate the flow. This may involve massaging your eye and possibly removing sutures.
It is expected that your vision will fluctuate in the first few weeks, due to the variable drainage of fluid, but will eventually stabilise.
For any eye surgery there is the risk of infection, bleeding, loss of vision and the potential for retinal problems. Trabeculectomy surgery, in particular, can be associated with problems of under or over drainage following the surgery either due to loosening of the sutures or wound leak. Occasionally, if the drainage is not controlled, then the trabeculectomy may need to be revised, which involves going back to the operating theatre. This does not occur frequently but if required, it is in the best interest of your eye.
Patients generally have 1 week off work depending on how the eye is healing and the nature of their work. More physical work (lifting more 10kg or involving prolonged bending over), especially in dusty or dirty conditions, should be avoided in the first month. It is wise to wear sunglasses during the day and a shield at night.
The ultimate goal of trabeculectomy surgery is to reduce the pressure in the eye to a level that will slow the vision loss. Due to the progressive nature of glaucoma no current treatment cures the condition, however, achieving lower stable eye pressures gives you the best long-term chance to maintain a functional level of vision.