EXPRESS GLAUCOMA SHUNT
What is glaucoma?
Glaucoma is one of the most common causes of blindness for people aged over 40. Glaucoma affects more than 13% of the population above 60 years. It is a complex eye disease in which circulation of the fluid in the eye is disrupted. The eye has pressure just like blood vessels, and when this intraocular pressure increases to dangerous levels, it damages the optic nerve. This can result in decreased peripheral vision and, eventually, blindness if left untreated. Vision loss is caused by damage to the optic nerve. This nerve acts like an electric cable containing over a million wires. It is responsible for carrying images from the eye to the brain.
Often, people with glaucoma don’t even realize that they have a problem as there are no obvious symptoms. The eyesight deteriorates so gradually that it is often unnoticed. The only real way of knowing that glaucoma is present is by having an eye examination by an eye doctor.
What are the signs and symptoms of glaucoma?
In the vast majority of cases, especially in early stages, there are few signs or symptoms that can occur including:
- Subtle loss of contrast.
- Difficulty driving at night.
- Loss of peripheral vision.
- Rainbow colored rings or halos around lights.
- Frequent need to change eyeglass prescriptions.
As glaucoma progresses, the optic nerve can be damaged. This can cause irreversible loss of peripheral vision.
How is glaucoma treated?
Treatment varies from person to person. In the early stages of the disease, glaucoma can be controlled by medication (eye drops) or laser surgery. Medication and laser surgeries may not always be effective enough; therefore, at times your doctor may recommend what is called glaucoma filtration surgery.
The traditional glaucoma filtration surgery is called trabeculectomy. In this operation, a small hole is made in the wall of the eye (sclera) to create an opening or new filtering pathway for the fluid to exit the eye. After this, a small section of the iris is excised (cut out) to ensure the fluid pathway will not be blocked. Trabeculectomy surgery has been done in one way or another for the past 30 years.
The Ex-PRESS mini glaucoma shunt (excessive pressure regulating shunt system) provides a simplified method of filtration surgery for patients with glaucoma.
The Ex-PRESS may be implanted following cataract surgery.
How does the Ex-PRESS mini shunt work?
The Ex-PRESS mini shunt is a relatively new device, available in USA since 2002. Over 12,000 implantations have been performed worldwide. It is a straightforward procedure, in which you divert the fluid through an extremely small tube to the outside of the eye. You neither cut sclera, nor iris. Although the device is as small as a grain of rice, it acts just like a heart stent keeping a pathway open so blood (or fluid) can successfully go around the blockage. The Ex-PRESS provides precise control of the amount of fluid that is allowed to flow out helping the eye maintain a healthy level of internal pressure.
The Ex-PRESS mini glaucoma shunt provides effective long term control of intraocular pressure, with a success rate of about 94% 2. It can be done following cataract surgery.
The Ex-PRESS has an equally effective intraocular pressure control compared with trabeculectomy, but is safer than trabeculectomy in the short term 3.
In most cases, patients virtually eliminate their need for glaucoma eye drops after Ex-PRESS surgery.
1. Glaucoma surgery by John Thomas, MD, Chief Editor, Mosby – Year Book, Inc. 1992
2. Microsurgery Of The Eye Conference, January 2006
3. EX-PRESS Meet The Experts, October 2005
Frequently Asked Questions about Glaucoma
What causes glaucoma?
Glaucoma is caused when an excess amount of eye fluid (aqueous) is created and its regular drainage is damaged. This causes the aqueous to accumulate and build up pressure. This pressure can damage the optic nerve and cause a decrease in vision. Glaucoma is the second cause of blindness in Caucasian populations and first cause of blindness in African-American populations.
Therefore, glaucoma can be treated with a device to shunt the aqueous out of the eye, and hence, lower the inner eye pressure (IOP).
What is the Ex-PRESS?
The Ex-PRESS is a small device (like the size of a grain of rice) that is implanted between the inner region of the eye and the outer region. The Ex-PRESS mechanism of action is by bypassing the normal drainage system of the eye that has been damaged by glaucoma. The aqueous then drains into a space under the conjunctiva. The conjunctiva is the thin layer of tissue that covers the sclera, or “white” part of the eye. This area of drainage is covered by the eyelid.
What are the treatments for glaucoma?
Traditionally, glaucoma is first treated by administration of eye drops. If the eye drops are not effective, laser procedures may be performed to open the drain if your doctor thinks this is appropriate. If laser is ineffective, or not appropriate for your type or level of glaucoma, a filtering procedure such as the Ex-PRESS mini shunt implantation may be needed to preserve your vision.
Does the Ex-PRESS mini glaucoma shunt cure glaucoma?
Since only the symptoms of glaucoma can be treated, glaucoma cannot be cured. The Ex-PRESS mini glaucoma shunt treats the symptoms of glaucoma and prevents a further deterioration in vision. However, previous damage to your sight cannot be reversed.
How long is the procedure?
The Ex-PRESS procedure is fast and simple. It takes about 45 minutes, all together.
When would I be able to return to work?
The pressure-lowering effect of the Ex-PRESS is immediate. You might be able to return to work within 2-7 days after the procedure; however, this will vary. Please advise your doctor for further information.
When can I expect the final results?
The Ex-PRESS shunt starts to work immediately. During the first 4 weeks, the eye pressure is stabilized to new levels. In most cases, after that time, your eye pressure will be maintained. Your vision will be back to normal shortly after the procedure.
Is it safe to implant a metal piece in the eye?
The Ex-PRESS is manufactured from stainless steel which is commonly used in human implantations including cardiac stents. The Ex-PRESS has been proven to be biocompatible and MRI safe.
Will I still need medications with the Ex-PRESS glaucoma shunt?
Most patients, after Ex-PRESS implantation, don't need their glaucoma medications anymore since the Ex-PRESS is very effective at lowering the inner eye pressure. However, your doctor may recommend medications at some point after the surgery if your glaucoma is very severe.
What are the advantages of the Ex-PRESS mini glaucoma shunt?
The Ex-PRESS mini glaucoma shunt implantation has a high success rate at lowering intraocular pressure (IOP). This mini glaucoma shunt has fewer complications compared with standardized trabeculectomy. The Ex-PRESS can be used in combination with a cataract surgery.
Is the procedure painful?
Since local anesthesia is used during surgery, there is virtually no pain involved. After surgery, if any discomfort is felt, Tylenol can be used. Most of the discomfort is associated with the dissolvable sutures used to close the conjunctiva, which is the thin layer of “skin” that covers the eyeball. Careful compliance with the medications prescribed after the surgery should help alleviate this discomfort until the sutures dissolve.
What are the success rates of the Ex-PRESS?
The Ex-PRESS is a highly successful and effective procedure. The success rates stand at around 90%. This is comparatively high to other traditional procedures.
Should I make any special preparations prior to the procedure?
No special preparation is needed. You may be required to stop any medicines you take that thin you blood (for example, Coumadin, Plavix, or Aspirin). Please advise your doctor for more information.
Are there any complications or side effects with the Ex-PRESS mini glaucoma shunt implantation?
The complications are similar to other intraocular procedures, but they were found to be less frequent with the Ex-PRESS mini shunt. The risks involved with any intraocular surgery are namely inflammation, infection, bleeding, and decrease in vision, although with the Ex-PRESS mini shunt these risks may be reduced compared to traditional glaucoma surgery.
What are the follow up appointment periods?
Usually, just as with other inner eye procedures, the follow up appointments are typically on the first day after surgery, the first week and the first month. After that, every 3rd month follow up is recommended. Your doctor may recommend more frequent visits depending his/her usual practice and other factors that may arise after your surgery.
For more information download our Ex-PRESS mini shunt pamphlet.