Glaucoma

The Basics

What is glaucoma?
Glaucoma is a disease of the optic nerve, which is the part of the eye that carries the images we see from the eye to the brain. The optic nerve is made up of many nerve fibers (like an electric cable containing numerous wires). Glaucoma damages nerve fibers, which can cause blind spots in our vision and vision loss to develop.

Glaucoma has to do with the pressure inside the eye, or intraocular pressure (IOP). When the clear liquid called the aqueous humor—which normally flows in and out of the eye—cannot drain properly, pressure builds up in the eye. The resulting increase in IOP can damage the optic nerve.

The most common form of glaucoma is primary open-angle glaucoma, where the aqueous fluid that normally circulates in the front portion of the eye is blocked from flowing back out of the eye through a tiny drainage system. This causes the pressure inside your eye to increase, which can damage the optic nerve and lead to vision loss. Most people who develop primary open-angle glaucoma notice no symptoms until their vision is impaired.

In angle-closure glaucoma, the iris (the colored part of the eye) may drop over and completely close off the drainage angle, abruptly blocking the flow of aqueous fluid and leading to increased IOP or optic nerve damage. In acute angle-closure glaucoma there is a sudden increase in IOP due to the buildup of aqueous fluid. This condition is considered an emergency because optic nerve damage and vision loss can occur within hours of the problem. Symptoms can include nausea, vomiting, seeing haloes around light, and eye pain.

Even people with "normal" IOP can experience vision loss from glaucoma. This condition is called normal tension glaucoma. In this type of glaucoma, the optic nerve is damaged even though the IOP is considered normal. Normal tension glaucoma is not well understood, but we do know that lowering IOP has been shown to slow progression of this form of glaucoma.

Childhood glaucoma is rare, and starts in infancy, childhood or adolescence. Like primary open-angle glaucoma, there are few, if any, symptoms in the early stage. Blindness can result if it is left untreated. Like most types of glaucoma, this type of glaucoma may run in families.

Your ophthalmologist may tell you that you are at risk for glaucoma if you have one or more risk factors, including elevated IOP, a family history of glaucoma, a particular ethnic background, advanced age, or certain optic nerve conditions. Regular examinations with your ophthalmologist are important if you are at risk for this condition.

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Alpha Agonists for the Treatment of Glaucoma

While there is no cure for glaucoma, it can be controlled.

Elevated intraocular pressure (IOP) may damage the optic nerve, which can lead to vision loss. Treatment for glaucoma focuses on lowering the IOP to a level that is less likely to cause further optic nerve damage. This is known as the "target pressure" or "goal pressure." The target pressure differs from individual to individual. Your target pressure may change during your course of treatment.

If you have glaucoma, your ophthalmologist (Eye MD) may prescribe medication to lower your eye pressure. There are many more choices for topical treatment (eyedrops) today than there were only a few years ago. Your ophthalmologist has chosen an alpha agonist medication to treat your glaucoma.

How Do Alpha Agonists Work?
Alpha agonist medications are reliable for lowering the intraocular pressure. They work by decreasing the production of the fluid that the eye continually makes, called the aqueous humor.

What Are the Alpha Agonists?
There are two alpha agonist drugs:

• Apraclonidine (Iopidine,)
• Brimonidine (Alphagan,)

Generic versions of these medications are not yet available.

Possible Side Effects of Alpha Agonists
All medications, including eyedrops, have not only benefits but may also have side effects. Some people taking alpha agonist eyedrops may experience:

• Dry mouth
• Ocular allergy with a red eye and/or red eyelids
• Headache, fatigue, irritability or sleep disorder
• Low or high blood pressure and possible slowing of heart rate (less than with beta blockers)
• Joint aches
• Upset stomach, nausea or constipation

For glaucoma medications to work, you must take them regularly and continuously as prescribed by your doctor.

Medication Tips
With each new medication that your ophthalmologist prescribes, make sure you understand the following:

• The name of the medication
• How to take it
• How often to take it
• How to store it
• If you can take it with your other medications (make sure each of your doctors knows about all the different medications you take, including non-prescription medications)
• What the possible side effects may be
• What you should do if you experience side effects
• What you should do if you miss a dose

Beta Blockers for the Treatment of Glaucoma

While there is no cure for glaucoma, it can be controlled.

Elevated intraocular pressure (IOP) may damage the optic nerve, which can lead to vision loss. Treatment for glaucoma focuses on lowering the IOP to a level that is less likely to cause further optic nerve damage. This is known as the "target pressure" or "goal pressure." The target pressure differs from individual to individual. Your target pressure may change during your course of treatment if the progression of glaucoma is not arrested.

If you have glaucoma, your ophthalmologist (Eye MD) may prescribe medication to lower your eye pressure. There are many more choices for topical treatment today than there were only a few years ago. Your ophthalmologist has chosen a beta blocker medication to treat your glaucoma:

How Do Beta Blockers Work?
Beta blocker (beta andrenergic antagonists) medications are reliable for lowering intraocular pressure. They work by decreasing the amount of fluid that the eye continually produces, called the aqueous humor. For many years, beta blockers were the mainstay of treatment. Hence, we have a lot of experience with this medication for the treatment of glaucoma.

Types of Beta Blocker Medication
There are two general classes of beta blockers: nonselective and selective. Nonselective beta blockers have more effects on the body's beta receptors system-wide, and are associated with more side effects. The nonselective beta-blockers are also more effective at lowering intraocular pressure.

• The nonselective beta blockers include:
• Levobunolol (Betagan)
• Timolol hemihydrate (Betimol)
• Carteolol (Ocupress)
• Metipranolol (Optipranolol)
• Timolol maleate (Timoptic) and Timolol maleate gel (Timoptic XE)

(Generic versions of Timolol are now available. Check with your ophthalmologist to make sure that a generic product is an acceptable alternative for you.)

The only available selective beta blocker medication is:

• Betaxolol (Betoptic-S)

While a selective beta blocker eyedrop has a better safety profile, especially in terms of breathing symptoms, it still must be used with caution in patients with asthma or emphysema. The eye pressure lowering effect is slightly less with selective beta blockers. There is only a minimal additive effect in terms of lowering eye pressure in patients already taking oral beta blockers and there is the risk of further additive side effects. If you are already taking a beta blocker medication by mouth or if your primary care doctor newly prescribes a beta blocker, please notify your Eye MD.

Possible Side Effects of Beta Blockers
All medications, including eyedrops, have not only benefits but may also have side effects. Some people taking beta blocker eyedrops may experience:

• Increased or worse asthma or emphysema
• Slow or irregular heart beat and/or decreased response of heart rate to exercise
• Increased risk for heart failure
• Depression or change in sex drive (impotence)
• Headache or dizziness or weakness
• In diabetics, difficulty sensing blood sugar changes
• Eye irritation or allergy

Medication Tips
For glaucoma medications to work, you must take them regularly and continuously as prescribed by your doctor. With each new medication that your ophthalmologist prescribes, make sure you understand the following:

• The name of the medication
• How to take it
• How often to take it
• How to store it
• If you can take it with your other medications (make sure each of your doctors knows about all the different medications you take, including non-prescription medications)
• What the possible side effects may be
• What you should do if you experience side effects
• What you should do if you miss a dose

Carbonic Anhydrase Inhibitors (CAIs) for the Treatment of Glaucoma

While there is no cure for glaucoma, it can be controlled.

Elevated intraocular pressure (IOP) may damage the optic nerve, which can lead to vision loss. Treatment for glaucoma focuses on lowering IOP to a level that is unlikely to cause further optic nerve damage. This is known as the "target pressure" or "goal pressure." The target pressure differs from individual to individual. Your target pressure may change during your course of treatment. If you have glaucoma, your ophthalmologist (Eye MD) may prescribe medication to lower your eye pressure. There are many more choices for topical treatment today than there were only a few years ago. Your ophthalmologist has chosen a carbonic anhydrase inhibitor medication to treat your glaucoma.

How Do Carbonic Anhydrase Inhibitors (CAIs) Work?
Carbonic anhydrase inhibitor medications are very reliable at lowering the intraocular pressure. They work by decreasing the production of the fluid that the eye continually makes, called the aqueous humor.

What are Carbonic Anhydrase Inhibitor Medications?
Topical drugs:

• Dorzolamide (Trusopt)
• Brinzolamide (Azopt)

Oral Medications:

• Acetazolamide (Diamox)
• Methazolamide (Neptazane)

Generic versions of the eyedrop formulations are not yet available.

Possible Side Effects of Carbonic Anhydrase Inhibitors
All medications, including eyedrops, have benefits but may also have side effects. Some people taking carbonic anhydrase medications may experience:

• Blurred vision
• Change in taste (especially with carbonated beverages)
• Dry Eye
• Eye irritation or allergy with a red eye and/or red eyelids
• Headache or dizziness
• Upset stomach

The oral (pill) form of these medications has more side effects, including:

• Increased need to urinate
• Tingling sensation in fingers and toes

Rarely, severe allergic reactions or blood disorders can occur

WARNING: These medications are sulfonamides, therefore, if you are allergic to sulfa antibiotics, the same types of adverse reactions can occur with carbonic anhydrase inhibitors. Also, rare adverse drug interactions have occurred in patients taking high doses of aspirin and carbonic anhydrase inhibitors.

For glaucoma medications to work, you must take them regularly and continuously as prescribed by your doctor.

Medication Tips:
With each new medication that your ophthalmologist prescribes, make sure you understand the following:

• The name of the medication
• How to take it
• How often to take it
• How to store it
• If you can take it with your other medications (make sure each of your doctors knows about all the different medications you take including non-prescription medications)
• What the possible side effects may be
• What you should do is you experience side effects
• What you should do if you miss a dose

Glaucoma: People of African Descent are at Risk

If you are of African ancestry, especially if you have a known family member with glaucoma, you are at risk for vision loss from this eye disease.

Glaucoma is a disease of the optic nerve, which is the part of the eye that carries the images we see from the back of the eye to the brain. The optic nerve is made up of many nerve fibers (like an electric cable containing numerous wires). Glaucoma damages nerve fibers, causing blind spots and loss of vision to develop.

Glaucoma has to do with the pressure inside your eye, or intraocular pressure (IOP). When the clear liquid called the aqueous humor—which normally flows in and out of the eye—cannot drain properly, pressure builds up in your eye. The resulting increase in IOP can damage the optic nerve.

Primary open angle glaucoma is the leading cause of blindness among people of African descent, occurring at a rate four times higher than among Caucasian patients. It also occurs about ten years earlier among people of African ancestry than among Caucasians, and develops more rapidly. Studies show that in the United States, people of African descent between the ages of 45-64 are approximately 15 times more likely to go blind from glaucoma than Caucasians with glaucoma in the same age group.

It is not clear why people of African ancestry have higher rates of glaucoma and subsequent blindness than Caucasians. One factor may be that African-Americans are more susceptible to developing elevated eye pressure (IOP) earlier in life, which is thought to contribute to optic nerve damage and eventual vision loss. Another reason may be that patients of African descent are less likely than Caucasians to have early eye examinations that may detect and treat glaucoma.

The best way to protect yourself and your family members against vision loss from glaucoma is by being aware of the higher risk of developing this disease, and by having regular eye examinations for glaucoma at appropriate intervals.

If you are at risk for developing glaucoma, you can help to protect yourself fro vision loss by having regular eye examinations for glaucoma at appropriate intervals. Recommended intervals for a comprehensive eye evaluation in people of African descent are:

• Age 20-29: every 3-5 years
• Age 30-64: every 2-4 years
• Age 65+: every 1 to 2 years

If you are diagnosed with glaucoma, please make sure you tell your family members and urge them to have an eye exam for glaucoma. For more information on glaucoma:

The Glaucoma Foundation
116 John Street, Suite 1605
New York, NY 10038
Phone: 1-800-GLAUCOMA
(1-800-452-8266)
www.glaucoma-foundation.org

The National Eye Institute
2020 Vision Place
Bethesda, MD 20892-3655
Phone: (301) 496-5248
www.nei.nih.gov

Prevent Blindness America
1-800-331-2020
www.preventblindness.org

The American Academy of Ophthalmology
P.O. Box 7424
San Francisco, CA 94120-7424
www.aao.org

• Latanoprost (Xalatan,)
• Bimatoprost (Lumigan,)
• Travoprost (Travatan,)
• Uniprostone (Rescula,)

• Redness of the eye
• The iris (the colored part of the eye) may darken or turn brown (this change in color occurs slowly and may not be noticeable for months or even years);
• Increased growth, thickness and pigmentation of the eyelashes;
• Eye irritation or itching;
• Blurred vision;
• Darkening of the eyelid skin;
• Muscle aches (rare);
• Headache (rare).

• With each new medication that your ophthalmologist prescribes, make sure you understand the following:
• The name of the medication
• How to take it
• How often to take it
• How to store it
• If you can take it with your other medications (make sure each of your doctors knows about all the different medications you take, including non-prescription medications)
• What the possible side effects may be
• What you should do if you experience side effects
• What you should do if you miss a dose