GLAUCOMA SURGERY

Surgery is not always necessary to treat glaucoma. Medications can often control the pressure in the eyes, preventing further vision loss and blindness. Medication will usually be tried first before surgery is considered.

Surgery may be needed for:

·                             Sudden (acute) angle closure glaucoma. Laser treatment can create an opening in the colored part of the eye (iris) that will let fluid drain from the eye. People who have had closed-angle glaucoma in one eye usually need to have laser treatment on the other eye to prevent the same condition from developing. Also, people who have narrow drainage area may need laser treatment to prevent acute closed-angle glaucoma. If laser treatment is not successful, then conventional surgery, such as surgical iridectomy or trabeculectomy, would be needed.

·                             Open angle glaucoma, if the pressure in the eyes stays high or if damage to the optic nerve continues despite medication. Laser treatment may be needed early on to treat open-angle glaucoma, especially in people who have very high intraocular pressure and severe glaucoma. In some cases, early surgery in open-angle glaucoma may be more effective than eye drops at reducing the pressure in the eyes and preventing blindness. 

·                             Infants with congenital glaucoma. They may need surgery as soon as possible to prevent blindness.

The goal of surgery for glaucoma is to preserve eyesight by:

1. Maintaining the health of the optic nerve.

2. Reducing the pressure in the eyes by opening blocked drainage angles or creating a new opening that fluid (aqueous humor) can flow through to leave the eye.

In some cases surgery may be done to relieve pain caused by glaucoma.

Surgery Options

There are three basic types of surgery for glaucoma in adults.

Surgery to increase drainage of fluid from the eye (Trabeculectomy, Tube-shunt surgery)

This type of surgery involves making a trapdoor that allows fluid to drain from the eye. In severe glaucoma, surgery also may involve putting in a filtering device (seton), usually made of plastic, that drains fluid away from the front part of the eye to a place where it can drain out of the eye. These procedures are used to treat Open angle glaucoma and long-term (chronic) angle closure glaucoma.

Surgery to prevent closure of the drainage angle (Iridectomy)

Surgery to prevent closure of the drainage system involves making a new opening in the colored part of the eye (iris) that allows fluid to flow through the eye. It is used to treat sudden (acute) closed-angle glaucoma and will prevent closed-angle glaucoma in people who have narrow drainage angles. Today, laser iridectomy can usually be done instead of surgical iridectomy. However, some people with complicated or severe glaucoma may need to have surgical iridectomy.

Surgery to decrease the amount of fluid produced in the eye (Cyclocryotherapy)

When other surgery fails to improve the flow of fluid from the eye, procedures to destroy the part of the eye that produces fluid (ciliary body) can be done. These procedures are also used when scar tissue has formed after a previous surgery.

Destroying the ciliary body decreases the amount of fluid produced in the eye, reducing the pressure in the eye. Procedures that decrease fluid in the eye are only used for people with severe glaucoma that has not gotten better after trying medications or other forms of surgery. This procedure can usually be done with a laser. In some cases, it may be done using an externally applied freezing probe or open surgery.

Surgery for congenital glaucoma (Goniotomoy, Trabeculotomy)

For congenital glaucoma, there are two slightly different procedures that both attempt to open the drainage angle directly. They are equally successful in children, but they are not used for adults. If these procedures fail in children, then trabeculectomy or tube-shunt surgery may be tried.

Considerations

Medications may be used before surgery to help clear a cloudy cornea (the clear covering over the front chamber of the eye).

Clouding of the lens (cataract) can develop after surgery for glaucoma and is one reason that surgery is not usually used first to treat open-angle glaucoma.

Cataracts may occur in people who also have glaucoma; this commonly occurs in older people. Surgery to remove the cataract may be done at the same time as surgery for glaucoma. The decision whether or not to have surgery is often more difficult in glaucoma than in many other conditions because:

        In many instances, the person is not in pain and often does not notice any vision loss.

        Surgery often causes a person's eyesight to get worse immediately after surgery. Vision may be affected for weeks or months after surgery. For some people, their eyesight is never as good as it was before the surgery. Surgery is not a complete cure for glaucoma. However, surgery can decrease the chance of losing even more eyesight later on.

As with any other surgery, you and your doctor should make the decision to operate based on the risks and benefits of having the surgery. Procedures to destroy the structures in the eye that produce fluid (cyclodestructive procedures) are usually used when other treatments, including other surgeries for glaucoma, have failed.  Several treatments over time can destroy too much of the ciliary body, causing too little fluid to be produced. This can cause the eyeball to soften and lead to clouding of the lens (cataract).