A trabeculectomy is a surgical technique used in the treatment of glaucoma which is an eye condition where the optic nerve is damaged, resulting in gradual and permanent loss of vision. It usually arises when the aqueous humor, the inner eye fluid, is unable to drain normally. The abnormality causes the intraocular pressure (IOP), i.e., the internal eye pressure to rise over time, which causes optic nerve damage and reduced vision or blindness if untreated.
Trabeculectomy can lower the IOP by creating a new passage or channel through which the humor can drain from the eye. It can reduce or stop the loss of vision caused by glaucoma. The eye doctor may recommend this procedure in case a patient is unresponsive to the regular glaucoma therapy such as prescription eye drops or medication.
When successful, the procedure is very effective at lowering the IOP. It’s considered one of the gold standard techniques, especially for moderate to advanced glaucoma patients. However, it’s essential to note that the procedure doesn’t cure any vision loss associated with glaucoma that the patient might have previously experienced. Trabeculectomy may only help decrease or stop the progressive loss of vision caused by the disease.
Preparation & Expectation Before Surgery
During the consultation before the surgery, the surgeon and the patient discuss the procedure. S/he will take a detailed medical and surgical history, including assessing any pre-existing eye conditions that may cause complications during or after the operation. S/he will also conduct a comprehensive eye examination to evaluate the affected eye and address any possible underlying disorders before the surgery, mainly where the patient will be under general anesthesia.
The patient should inform the surgeon about any medication and dietary supplements they are on, including eye drops, blood thinners, etc. S/he will guide whether to stop or continue with the routine. The patient may also be required to fast for 12 hours before the operation which will be done with general anesthesia.
Types, Purpose & Procedure
Trabeculectomy is a delicate procedure performed in an operating room under general or local anesthesia. If the patient is getting local anesthesia, the surgeon may give them a sedative to make it easier to relax. In the case of general anesthesia, the patient will be given monitored anesthesia for sedation.
The patient’s eye will be numbed, cleaned, and a lid speculum used to hold it open. The patient is then covered in a drape that only exposes their eye. The surgeon will help the accumulated humor flow out of the eye by making a new drainage canal. S/he will do so by making a small cut in the white part of the eye and removing some of the inner tissue mesh. During the operation, the patient is conscious, but will not feel anything. The surgery takes about an hour, and later the eye is patched to shield the stitches.
Risks, Side Effects &Complications
The common risks are pain and low IOP. In some rare cases, the patient may experience:
- Vision loss
- Loss of the eye
- Choroidal detachment
- Developing a hole close to the new channel
The side effects of the operation include discomfort, redness, soreness and blurry vision in the affected eye.
Complications may include:
- Double vision
- Drooping eyelid
- Additional operation
After Care, Recovery & Results
After surgery, the patient may have to stop using their regular glaucoma medications in the affected eye. The surgeon will prescribe medication, including antibiotics and steroid eye drops and aftercare instructions. The patient must follow the strict routine of applying the medication throughout the day for the given period, usually two to three months. It serves to control inflammation and prevent infection. After this period, s/he will advise the patient on whether they will need to continue any glaucoma medications.
The patient will also be required to sleep with the eye patch to protect the wound for the first two weeks. The surgeon will see the patient the day after the operation and schedule regular follow up checks. It enables him/her to monitor the healing progress and the IOP in the affected eye. S/he will remove the stitches in about two weeks following the surgery.
The patient may continue to experience blurred vision for 2 to 12 weeks. The patient can watch TV and read but will need to keep water out of the eye and avoid certain activities such as bending, high-impact exercise, sports, yoga, etc. The surgeon will advise the patient when to resume their normal activities. Generally, office workers may resume work after two weeks, while other workers could take a little longer.
Over 90 percent of the cases are successful, and close to two-thirds of the patients no longer need glaucoma medication for at least five years afterwards. About ten percent of the patients may need additional surgery. In about 20 percent of the cases, the technique controls the IOP for about 12 months