Glaucoma - Treatment

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Prostaglandins

Prostaglandins are hormone-like substances that help widen blood vessels. Drugs that mimic natural prostaglandins increase outflow of aqueous humor (the watery substance in the eye). Drainage of aqueous humor helps reduce intraocular pressure.

Brands. Latanoprost (Xalatan) and unoprostone (Rescula) are the standard brands. Latanoprost was the first prostaglandin to be approved as first-line treatment for elevated eye pressure. Two newer prostaglandins, travoprost (Travatan) and bimatoprost (Lumigan), may help some patients who do not respond to latanoprost. These drugs may also benefit patients with normal-tension glaucoma.

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Side Effects. These drugs do not slow down the heart rate and also appear to be safe for people with asthma. Side effects include itching, redness, and burning during administration. Muscle and joint pain may also occur. All of these drugs may permanently change eye color from blue or green to brown.

Carbonic Anhydrase Inhibitors

Carbonic anhydrase inhibitors (CAIs) decrease eye pressure by reducing the fluid in the chambers of the eye (aqueous humor). These drugs are used for glaucoma when other drugs do not work. They may be combined with other medications.

CAIs may also improve blood flow in the retina and optic nerve (beta-blockers do not). Improving blood flow can keep the disease from getting worse.

Brands and Side Effects. CAIs are available in the following forms:

• Eye-drop CAIs include dorzolamide (Trusopt) and brinzolamide (Azopt). About 10% of patients report fatigue, stinging in the eye, and loss of appetite using dorzolamide. Taste changes can occur. Brinzolamide is a newer medication that may cause less stinging than dorzolamide.
• Oral forms include acetazolamide (Diamox), methazolamide (Neptazane), and dichlorphenamide (Daranide). Although pill forms are more effective than eye drops, they have significantly more side effects and are rarely used for long-term treatment. Unpleasant side effects include frequent urination, depression, stomach problems, fatigue, weight loss, sexual dysfunction, and, in infants, failure to thrive. Long-term use of the oral forms, in rare cases, can cause serious anemia and kidney problems, including the risk for kidney stones. They can also produce a toxic reaction when taken with large doses of aspirin.