Medications For Glaucoma - Glaucoma: The Aging Eye Preventing And Treating Eye Disease

Content provided by the Faculty of the Harvard Medical School

Medications for glaucoma

In some respects, treatment of glaucoma is similar to that of heart disease. Both conditions have multiple causes and may require multiple medications. And in both cases, therapy represents a lifetime commitment. It's important to adhere to your treatment plan even when you may not feel any benefit, because quite often such benefits are intangible.

Take eye pressure, for example. Like blood pressure, intraocular eye pressure varies over the course of the day. Because an important goal of glaucoma treatment is to control eye pressure and stop the progression of the disease, your physician may tailor your medication schedule to address such fluctuations in eye pressure. Taking your medications on a regular schedule, and not skipping any doses, is important for keeping eye pressure under control throughout the day.

Regular exams are equally important, because without an exam, you don't know whether fluid pressure in your eye is in a safe range or whether your visual field is slowly deteriorating. People who have questions about their drugs, trouble following their treatment plans, or difficulty using their medicine should ask their doctors for advice and solutions.

For open-angle glaucoma, treatment usually begins with topical medications — eye drops or sometimes ointments — administered one to several times a day. (See "Types of medications" for a description of glaucoma drugs and how they work.) Depending on the severity of the condition, multiple drops and sometimes pills may be required. Most ophthalmologists begin with the lowest effective dose to minimize cost and potential side effects.

You can apply drops more easily by pulling your lower lid out to create a small pouch for the medicine. Gently closing your eye will ensure the medicine spreads over its surface. Generally, drops should be used every 12 hours if prescribed twice a day, every 8 hours if prescribed three times a day, and so forth.

Although eye drops help control pressure in the eye, they may have side effects that can keep you from using them. These may affect just the eye or your whole body, as the drops can enter your bloodstream through your nose and throat. You can minimize this by pressing your fingertip against the inner corner of the eye, to compress the tear duct and thus prevent the medicine from entering the drainage pathway into the nose.

Types of medications

The following classes of drugs are listed in the order an ophthalmologist is most likely to prescribe them. However, the doctor will adjust treatment to your individual needs. Depending on such factors as the severity of your glaucoma and your medical history, your doctor may prescribe these drugs in a different order or use two or more drugs in combination. The more commonly used medications tend to have fewer and less severe side effects than those less commonly prescribed (see Table 2).

Beta blockers. These eye drops contain medication similar to the beta blockers used to treat some types of heart disease. Beta blockers lower pressure in the eye by reducing the amount of aqueous humor produced by the ciliary body. This class of medication is usually well tolerated, but side effects may occur. You may use topical beta blockers even if you are also taking beta blockers in pill form for heart disease, but you should notify both your ophthalmologist and physician that you are doing so. Topical side effects may include allergic reactions and irritation.

Prostaglandins. These eye drops are commonly used because they require only one application per day. This medication lowers eye pressure by increasing the flow of aqueous humor through the uveal and scleral tissues.

Alpha-2 agonists. These eye drops lower pressure in the eye by both decreasing production of aqueous humor and increasing the fluid outflow.

Carbonic anhydrase inhibitors. Medications in this class, also known as CAIs, can be used either orally or topically to decrease eye pressure by reducing the amount of aqueous humor produced in the eye.

Miotics. These are the oldest of the glaucoma medications in use. Applied as eye drops, they improve the capacity of the drainage system. Miotics are used infrequently because their side effects on vision are more common and troublesome than those of many other glaucoma medications.

Adrenergics. These drops contain either epinephrine or dipivefrin, which becomes epinephrine when absorbed into the eye. Adrenergics reduce the amount of aqueous humor and increase its outflow through the trabecular meshwork.

Hyperosmotics. For acute glaucoma, hyperosmotic medication may be taken orally or injected intravenously. The medication quickly reduces the pressure in the eye by pulling fluid from the eyeball into the internal eye blood vessels, so it can pass out of the eye with the normal blood flow.

Last updated:	June 19, 2007