In trabeculectomy surgery, an alternate drainage pathway is made to bypass your poorly functioning drainage system. This is achieved by making a "trap door"- like entrance into the front of the eye. It is placed at the top of your eye, and channels watery fluid from the inside of the eye to just under the surface skin (or conjunctiva) of the eye. The fluid collects to make a flattish or sometimes "blister-like" elevation on the top surface of the eye called a "bleb." This is hidden under your eyelid and usually does not show. You will not notice this fluid coming out unless there is a small leak. If there is a small leak of the wound, it will usually disappear after a few days. Rarely, you may need extra surgery to stitch it up.

Permanent stitches are used to hold down the "trap-door". They are under the surface of the eye, so you do not feel them. They may be cut with a laser (after the surgery in the clinic) to make the "trap-door" more leaky if the pressure is not low enough. The surface skin is closed with dissolvable stitches (or "sutures") that you may feel a little in the first few days after the surgery. However, they usually soften after a few days and disappear within a few weeks. Occasionally, your surgeon will remove them for you.

This surgery is done with a local anaesthetic and intravenous (IV) sedation. You will be awake but sleepy during the surgery. This is much safer than using a general anaesthetic. You will not be able to feel anything. If you have any discomfort, more freezing can be used.

In order to work, the "trap-door" that has been cut open in trabeculectomy surgery needs to stay open. However, our body has a natural tendency to heal wounds. Therefore, eventually this trap door will scar down and stop working. Your surgeon will use Mitomycin C, an anti-scarring medication used in chemotherapy. It is used in very minute doses to prevent scarring. However, despite this, scarring can still occur just after or months to years after the surgery. Therefore, in the weeks right after surgery, a lot of the work is done to make sure the "trap-door" or filter keeps working. You should expect several visits with your surgeon during this time.

These steps may include: putting you temporarily (or in some cases permanently) back on glaucoma drops, cutting stitches with a laser (done in the clinic) to make the "trap-door" more leaky and filter more water, or even doing a series of 5-FU (Fluorouracil) injections to the superficial surface of the eye. 5-Fluorouracil is another anti-scarring, chemotherapy medication used in minute doses to work against aggressive scarring in the early days after the surgery. At GEM Clinic, it is done in the office, on a weekly basis for up to 5 injections (or as needed). After all these efforts, if you still do not have good pressure control, you may need to have another type of surgery called Glaucoma Drainage Implant (Device) surgery with either an Ahmed or Baerveldt Glaucoma Drainage Device.

If you are having glaucoma surgery for the first time, trabeculectomy surgery is a good initial step that does not involve implanting a foreign body inside the eye. It is less invasive and may work to lower your pressures without the use of drops (adjuvant drops are usually required in the case of implanted devices). Trabeculectomy is a shorter operation, even though post-operative visits may be more frequent. However, if you need to have a second glaucoma surgery, an implanted device may be the appropriate next step.

These medications are anti-metabolites that prevent new cell growth. They are used to stop fibroblasts or scar-making cells from growing. They can sometimes affect the growth of normal cells, and cause delayed healing, persistent wound leak or thinning of the surrounding tissues. These drugs are used on the surface of the eye and are applied cautiously to prevent problems with the wound. However, if they get inside the eye, which is extremely rare due to the way they are used, they can potentially cause damage to the cornea, lens and other structures in the eye. A non-healing wound leak will be repaired by your surgeon since it can lead to infection, bleeding or very low pressures that all can cause poor vision or vision loss. Symptoms of such problems would be eye pain, excessive tearing, redness, or vision loss. If you experience these symptoms, you should contact your surgeon's office, or after hours, go to Misericordia Health Centre or your local emergency department as soon as possible.

Trabeculectomy surgery is much different than routine cataract surgery. Often the vision is blurry for weeks after the surgery, but it gradually gets better. Occasionally, especially if you already have very severe glaucoma damage to the optic nerve, you can suffer further permanent vision loss after surgery. This is rare, but can happen, even with routine, uncomplicated surgery. Other possible complications can include very high or very low pressures after surgery, over drainage of fluid causing collapse of the front chamber of the eye, wound leak, accelerated development of cataract, bleeding during or after surgery (which can be minor or major causing usually temporary but sometimes permanent vision loss), infection (rare but when severe can cause loss of the eye) or retinal detachment (rare with trabeculectomy surgery alone, but higher when cataract surgery or vitrectomy is done at the same time). (Please note: This is not an exhaustive list, but covers the most note-worthy potential risks.)

Please note that although this is a scary list of possible complications, most of these issues are treatable with reasonable ultimate outcomes. If you encounter a complication, every effort will be made to remedy the situation as much as possible, including further medication, laser or further surgery as needed. Your surgeon will discuss these options with you. Your patience and cooperation is greatly appreciated during this time since this will help the healing process immensely.

Anaesthetic complications are extremely rare but can happen even with the small amount of intravenous medications and local anaesthetics that are used. Most of the time, if a patient is comfortable, no drugs are used. However, if a patient is nervous and needs something to stay relaxed, a small amount of sedatives and painkillers are used in the intravenous. In some patients, use of local anaesthetics in and around the eye can cause decreased vision, bleeding and nerve changes. These effects are usually temporary and resolve with time. Rarely, there can be permanent damage. In rare patients with multiple medical problems, these drugs can potentially cause cardiac or neurological problems, resulting in serious illness or even death. We are certainly vigilant of any concerns with the use of medications in our patients and are prepared to deal with these kinds of emergencies. However, we cannot always predict when a serious drug reaction will occur. Thankfully, these complications are extremely rare with local procedures.

There are serious possible risks involved with trabeculectomy surgery. However, the reason you are being offered surgery, is because you are already at risk of losing more vision if your eye pressure remains uncontrolled. You are being offered surgery at this point because the benefits of doing surgery now, outweigh the possible risks.

Successful trabeculectomy surgery will ensure a low pressure for several years, sometimes requiring extra glaucoma drops to help keep the pressure down. Unfortunately, this effect may last 5 to 10 years (or more or less) and then another procedure or a revision of the surgery will have to be done to maintain an acceptable eye pressure. It is important to understand, that glaucoma is a progressive disease that changes over time. Regular monitoring and check-ups will ensure that you are keeping up with the changes. Although we cannot cure glaucoma, we can treat it effectively to help prevent significant vision loss during your lifetime.

Routine trabeculectomy surgery will take about 30-40 minutes (longer if any problems arise). When combined with cataract surgery, it can take up to an hour. You will need to be at the hospital 1.5 hours before your surgical time so that the hospital staff can get you ready for the surgery. After your surgery, you will have about 30 minutes to recover, and then will be able to go home. Usually, the entire visit for day surgery at the hospital will take about 4 hours.

You will be well frozen with local anaesthetic around the eye, therefore you should not feel anything during surgery. If you do have any discomfort or pain, you will be able to tell your surgeon this, and more anaesthetic will promptly be applied.

It is normal to feel some discomfort and irritation from the superficial stitches, and some light sensitivity after trabeculectomy surgery. The vision is usually blurry.

Symptoms such as severe pain, headache, vision loss, nausea and vomiting are unusual. If you experience any of these symptoms, you should contact your surgeon's office, or go back to Misericordia Health Centre immediately.

Trabeculectomy surgery is much different than routine cataract surgery. Blurred vision after trabeculectomy (alone or combined with cataract surgery) often lasts for several weeks after the surgery. When you have cataract surgery combined with any type of glaucoma surgery, you will need to get your glasses updated about 2 months after the surgery when things are stable. In comparison, when you have cataract surgery alone, you can update your glasses at least 1 month after surgery.

Rarely, especially for people who already have severe damage to their optic nerves from glaucoma, surgery can worsen vision permanently. This is rare, but can happen even with uncomplicated surgery. This may happen because the optic nerve in a person with advanced glaucoma may be too weak to tolerate the surgical trauma. Sometimes, a decision is made to avoid surgery, since the risk of losing vision is too high. However, in most cases, if there is persistently high eye pressure, surgery must proceed regardless of the risks, in order to prevent further damage to an already weakened nerve. Your surgeon will discuss the risks and benefits of surgery with you ahead of time, so that you can make an informed decision for your future eye health.