The Treatment of Glaucoma

The basic principle of treatment is to preserve the health of the patient. Because all treatments, medicines as well as surgeries, cause side effects, they should be used only when necessary. Because some glaucomas never get worse, some glaucomas never need treatment. On the other hand, those glaucomas which can cause blindness in a period of hours need to have extremely vigorous treatment. The challenge is to make the treatment appropriate for the particular type of glaucoma and for the particular person who is affected by that glaucoma.

Most types of glaucoma need treatment. The great majority of persons whose glaucoma is discovered early will retain their sight. The proper care of glaucoma demands an ongoing partnership between the patient and ophthalmologist. The two must speak to each other clearly so that the physician can accurately evaluate the patient's condition and the effects of the drugs, and the patient can understand what needs to be done.

Appropriate treatment will prevent loss of sight in the majority of persons whose glaucoma is detected early. Even for those with considerable loss of sight already, treatment of the far-advanced stages of the disease often can be effective in preventing further deterioration of sight. Moreover, when the glaucoma merely has damaged, rather than deadened, the fibers of the optic nerve, some return of function may occur.

The higher the intraocular pressure, the more likely is the possibility of progressive glaucoma damage. However, glaucomas that occur in association with low or average intraocular pressure are especially serious because the optic nerve of such patients is especially sensitive to damage! The physician tries to determine just what pressure level is safe for each individual. This usually takes repeated visits and repeated tests, often over a period of months or years.

Medications for Glaucoma

The major goal of glaucoma treatment is to preserve the health of the patient. Glaucoma damage is prevented by keeping intraocular pressure in a range that permits the best functioning of the eye. Treatment may be medical (drugs) or surgical, but other considerations are also important, such as blood pressure, nutrition, and body weight.

Pressure may be lowered by drops or pills that decrease the rate at which the watery fluid is made, or drops that assist the outflow of the fluid from the eye, or by laser treatment or surgery.

There are several classes of drugs. Drugs that block certain effects of the sympathetic nervous system (beta-blockers) are frequently used, and include timolol, betaxolol and carteolol. Interestingly, drugs that stimulate the sympathetic nervous system can also lower intraocular pressure, and include epinephrine, dipivalyepinephrine, apraclonidine, and brimonidine. Medications that decrease the ability of the eye to make aqueous humor are often beneficial and include dorzolamide, and brinzolamide eye drops, and acetazolamide and methazolamide tablets. Drops that make the pupil smaller and help the aqueous humor leave the eye include pilocarpine, carbachol, and echothiopate.

The general principle is to use as little medication as possible to achieve the desired benefit. Frequently a combination of medications works better than one medication alone.

Marijuana in the form of eye drops or taken systemically is not of benefit in patients with glaucoma.

Surgery for Glaucoma

In many cases, treatment is first started with medicine. In some cases, however, surgery is the most appropriate first step.

The success of surgical treatment depends on such factors as the type and extent of glaucoma, the presence of other conditions (such as cataracts), the skill and judgment of the surgeon, and the general health of the patient.

Different types of glaucoma may require different types of surgery:

In angle-closure glaucoma, making a hole in the iris (iridotomy) permits the watery fluid to flow from the back to the front of the iris. When this is done early in the course of illness, prior to adherence of the iris to the cornea, the surgery is usually curative. As complications are very rare, iridotomy is often advised in cases where closure or narrowness of the angle of the anterior chamber plays a role. Iridotomy is usually performed with a laser, though in some cases, standard surgery is used. Iridotomy is done as an outpatient procedure. In other cases, trabeculoplasty for open-angle glaucoma may be appropriate as initial treatment. Argon laser trabeculoplasty, in at least 50 percent of the cases where it is used, helps the aqueous drain from the eye to lower pressure. Even filtering surgery is sometimes the most appropriate first treatment.

Laser surgery has given ophthalmologists new and remarkably safe ways to control this disease, especially for the glaucoma that is associated with the vascular complications of diabetes. Argon laser trabeculoplasty, in at least 50 percent of the appropriate cases, helps the aqueous drain from the eye to lower pressure.

In another surgical procedure (guarded filtration), a block of tissue is removed in the area of the trabecular meshwork, thus creating a new channel for the exit of watery fluid. Surgery of this type may require a hospital stay but is often done as outpatient surgery. Prompt diagnosis and treatment are crucial. By and large, the earlier the surgery is performed, the better the outlook.

Surgical techniques using plastic tubes may be helpful in some types of glaucoma. The use of drugs such as mitomycin or 5-fluorouracil increases the success of some selected surgical cases. Other types of old or new and experimental procedures are indicated in some cases.

After Glaucoma Surgery

Patients having laser surgery usually have little or no blurring or disability after the first postoperative day. They have no limitation on their activity and may often return to work on the same day as the surgery. Even with filtering procedures, there are usually relatively few limitations on activity following glaucoma surgery. Immediately after discharge from the hospital, a patient may return to a relatively normal way of life, though if the intraocular pressure is below 6 mm Hg, straining in any form should be avoided.

Following filtration procedures, the vision will be blurred in the operated eye for a varying period of time, often around one month, depending upon the state of the eye prior to the surgery, the nature of the surgery, and the rate of healing. Complete recovery usually takes around 6 weeks following a guarded filtration procedure.

Glaucoma Control and Vision

The control of glaucoma is considered in terms of the health of the optic nerve and the visual field. When the optic nerve does not become progressively damaged, glaucoma is considered controlled, no matter whether the intraocular pressure is high or low. When the optic nerve becomes progressively damaged, the glaucoma is considered uncontrolled. This can occur even when the pressure is low. If a diagnosis is made early in the disease, control is usually possible. In fact, if a diagnosis is made before optic nerve injury has occurred, damage may be prevented. The result of optic nerve damage is loss of vision. When glaucoma first starts, usually it does not affect central vision, but rather the vision toward the inner corner of the eye. If you look down toward your nose, that corner of your visual field is the one in which persons with glaucoma first start to lose their vision. Because that part of the visual field is seen with both eyes, and because glaucoma virtually always affects one eye first, most people do not notice this visual loss in its early stages.

With glaucoma, visual loss can often be detected only by specifically testing for it. That is why it is necessary to have regular routine eye examinations. Prompt treatment can help some individuals return the loss of some vision though only rarely can the full field of vision be restored. For others, treatment will help to control the disease and prevent further damage to the optic nerve.