The loss of vision due to glaucoma is irreversible. The treatment for this eye condition consists of eye drops, tablets, laser surgery, surgery or a combination of these treatments. Good treatment of the eye disease glaucoma is possible thanks to early detection. Patients often retain their vision thanks to medical and/or surgical treatment. Sometimes the ophthalmologist does not achieve the desired result with eye pressure-lowering medication for glaucoma, or the patient has unacceptable side effects. In that case, the ophthalmologist suggests a conventional surgical procedure: trabeculectomy.
- Contents of trabeculectomy: Treating patient with glaucoma
- Before the procedure
- During the procedure: Lowering the eye pressure via surgery
- After the procedure
- Complications
- Prognosis
Contents of trabeculectomy: Treating patient with glaucoma
Laser therapy is a possible treatment for the eye condition glaucoma. However, if this therapy does not lead to lower eye pressure, conventional surgery is recommended. The most common conventional surgical procedure is a trabeculectomy, also known as filtration surgery. A surgeon performs this procedure in both open-angle and closed-angle glaucoma. In this treatment, the surgeon makes an opening in the sclera (the white part of the eye) so that excess eye fluid (aqueous humor) can drain from the eye. The fluid bypasses the clogged drainage channels of the trabecular system (drainage system). When the fluid flows through the new drainage opening, a kind of “air bubble” is formed. This is a sign that fluid is draining from the space between the sclera and conjunctiva. This bubble is not visible to others unless at very close range. The patient then gradually achieves the target eye pressure painlessly thanks to this “controlled leak”.
Before the procedure
It is best for the patient to inform the doctor in a timely manner which medication he is taking. It is best for the patient to discontinue blood thinners several days to weeks before the operation. Normally the patient takes eye pressure lowering medication until the day of the operation. The treatment is done on an outpatient basis in adult patients, so the patient can go home immediately after the procedure. Sometimes children stay in the hospital overnight for observation. The patient receives local or general anesthesia before the operation. This depends on many factors including the ophthalmologist’s preference, the patient’s health, the severity of the glaucoma, and so on.
During the procedure: Lowering the eye pressure via surgery
The operation takes approximately one hour. The patient is first given some anesthetic eye drops. Sometimes he is also given a sedative to make him feel comfortable during the operation. The patient is then given sterile sheets over his face and body. The surgeon naturally keeps the eye to be operated on free. This way, the entire operating area remains clean and sterile. The surgeon then uses a special instrument (spacer) to keep the eye open continuously. This way it does not matter if the patient blinks because the eye still remains open. The trabeculectomy itself then takes place (see: “intervention contents”).
After the procedure
Immediately after the procedure, the eye is covered with a cap for protection. This plastic protective cap remains in place until the anesthesia has worn off. It is also best for patients to wear the protective cap at night so that they do not accidentally rub the operated eye. Because the patient is temporarily unable to estimate depth and distances, he is not allowed to drive home by himself. He therefore provides transportation. The patient usually discontinues glaucoma medications to allow the fluid to subside. After the procedure, the patient takes antibiotic drops four times a day as well as prednisolone drops (corticosteroids) every two hours, which have an anti-inflammatory effect. The patient takes these drops until one to two months after the operation. Normally, a patient reports back to the ophthalmologist a few days after the procedure for a first check-up visit. The number of postoperative visits to the doctor varies per patient and the recovery is also determined individually. In any case, the ophthalmologist will look at the air bubble to ensure that the excess fluid still drains from the new opening. The patient may resume a number of activities such as driving, reading, bending and heavy lifting two to four weeks after surgery. Furthermore, some patients use laxatives (drugs for constipation) if they suffer from constipation. Straining increases the risk of bleeding and causes damage to the optic nerve.
Complications
Sporadically, the surgically created drainage opening closes and the eye pressure rises again. The body tries to heal the new opening and sees this as a kind of “wound” that the body must close. This complication is more common in young people, patients with a dark skin color and patients who have previously had eye operations. Many surgeons therefore perform a trabeculectomy with an anti-fibrotic agent that they place against the eye during the operation. In medical terms, an antifibrotic agent is an agent that reduces scarring during the recovery period. The most common anti-fibrotic agent used by the surgeon is mitomycin-C, but also 5-fluorouracil, or 5-FUt.
In some patients, a trabulectomy is not successful; they sometimes have to go under the knife again or need other treatments. In addition, a patient’s vision is blurred (blurred vision), he or she experiences bleeding in the eye or he suddenly loses his central vision permanently. Very sporadically, increased eye pressure occurs (malignant glaucoma), and too low eye pressure (leaking air bubble) also occurs. An infection may occur just after or even long after the operation. In the long term, developing cataracts is a possible complication. Drooping eyelids and persistent changes in the optic nerve at the back of the eye also occur.
Prognosis
About 50% of patients do not need glaucoma medication for an extended period of time after surgery. About 35 to 40% of patients who still require medication have better eye pressure control. However, sometimes reoperation and/or other treatment is required because the trabeculectomy has not achieved the desired effect. The surgeon may consider drainage with a Baerveldt implant if the trabeculectomy has failed.
read more
- An eye exam at the ophthalmologist: Screening for eye diseases
- Laser treatment for eye condition glaucoma
- Tonometry: Eye pressure measurement to detect glaucoma
- Glaucoma: Baerveldt drainage implant to lower eye pressure
- Visual field examination: Examination of visual field loss
