Glaucoma - Treatment

Medications

Nearly all glaucoma medications are prescribed to reduce eye pressure.

Beta-blockers (Timolol and Others)

Topical beta-blockers are the drugs most often prescribed to treat glaucoma. They lower the pressure inside the eye by inhibiting the production of aqueous humor.

Brands. These drugs are categorized as either nonselective or selective beta-blockers:

• Nonselective adrenoceptor beta-blockers. Timolol (Timoptic, Betimol) has been the standard beta-blocker for years. Newer nonselective drugs include levobunolol (Betagan), carteolol (Ocupress), and metipranolol (OptiPranolol).
• Selective beta1-adrenoceptor blockers. Betaxolol (Betoptic) and levobetaxolol (Betaxon) are selective beta-blockers. These drugs may have fewer adverse effects on the heart than the nonselective beta-blockers, although they still have widespread effects.

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All beta-blockers work well and generally well tolerated. Because they cause less eye irritation than many other glaucoma medications, they are often prescribed for patients who also have cataracts.

Side Effects and Complications. After the beta-blocker is administered, only a tiny amount of the drug is absorbed by the cornea. Most of it enters in the bloodstream. These drugs, therefore, can cause side effects in parts of the body other than the eyes ("systemic" side effects):

• Systemic side effects may include reduced sexual drive, fatigue, depression, anxiety, and breathing difficulties.
• Beta-blockers affect the heart. They lower heart rate and reduce blood pressure.
• Beta-blockers can worsen severe asthma or other lung diseases.
• A patient switching to a beta-blocker from other glaucoma medication may feel a sudden rise in eye pressure. It is important that the pressure be checked shortly after the other drug has been withdrawn.
• When beta-blockers are used to treat one eye, the other (contralateral) eye also experiences a lesser, but still significant reduction in IOP.

Interactions with Other Medications. The effects of the eye medication can interact with oral medications, such as other beta-blockers, calcium-channel blockers, or the antiarrhythmic drug quinidine. People with diabetes who take insulin or hypoglycemic medications should realize that beta-blocker side effects may mask the symptoms of hypoglycemia (low blood sugar).