Glaucoma is a group of diseases that damage the eye’s optic nerve and can result in vision loss and blindness. However, with early detection and treatment, you can often protect your eyes against serious vision loss. The most common type of Glaucoma is Open angle.
The optic nerve
The optic nerve is a bundle of more than 1 million nerve fibers. It connects the retina to the brain. (See diagram above.) A healthy optic nerve is necessary for good vision.
How does the optic nerve get damaged by open angle glaucoma? Several large studies have shown that eye pressure is a major risk factor for optic nerve damage. Hence increased eye pressure may damage optic nerve and vision loss—may result. Another risk factor for optic nerve damage relates to blood pressure. Thus, it is important to also make sure that your blood pressure is at a proper level for your body.
Can I develop glaucoma if I have increased eye pressure? Not necessarily. Not every person with increased eye pressure will develop glaucoma. Some people can tolerate higher levels of eye pressure better than others. Also, a certain level of eye pressure may be high for one person but normal for another.
Can I develop glaucoma without an increase in my eye pressure? Yes. Glaucoma can develop without increased eye pressure. This form of glaucoma is called low-tension or normal-tension glaucoma.
Who is at risk for open-angle glaucoma? Anyone can develop glaucoma. Some people, listed below, are at higher risk than others:
- African Americans over age 40
- Everyone over age 60
- People with a family history of glaucoma
Glaucoma Symptoms
At first, open-angle glaucoma has no symptoms. It causes no pain. Vision stays normal. Glaucoma can develop in one or both eyes. Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eye. They seem to be looking through a tunnel. Over time, straight-ahead (central) vision may decrease until no vision remains.
**How is glaucoma detected? **Glaucoma is detected through a comprehensive dilated eye exam that includes the following:
- Visual acuity test. This eye chart test measures how well you see at various distances.
- Visual field test. This test measures your peripheral (side vision). It helps your eye care professional tell if you have lost peripheral vision, a sign of glaucoma.
- Dilated eye exam. To examine your retina and optic nerve for signs of damage.
- Tonometry is the measurement of pressure inside the eye by using Tonometer.
- Pachymetry is the measurement of the thickness of your cornea.
- OCT: Optic nerve and Retina scanning which is eye version of CT or MRI scan of the body.
Can glaucoma be cured? No. There is no cure for glaucoma. Vision lost from the disease cannot be restored. Can glaucoma damage prevented? Yes; with early detection and appropriate treatments
What are Glaucoma Treatment Options?
Glaucoma treatments include medicines, laser trabeculoplasty, conventional surgery, or a combination of any of these. While these treatments may save remaining vision, they do not improve sight already lost from glaucoma.
- Medicines. Medicines, in the form of eye drops or pills, are the most common early treatment for glaucoma. Taken regularly, these eye drops lower eye pressure. Some medicines cause the eye to make less fluid. Others lower pressure by helping fluid drain from the eye.Because glaucoma often has no symptoms, people may be tempted to stop taking, or may forget to take, their medicine. You need to use the drops or pills as long as they help control your eye pressure. Regular use is very important.
- Laser trabeculoplasty. Laser trabeculoplasty helps fluid drain out of the eye. Your doctor may suggest this step at any time. In many cases, you will need to keep taking glaucoma medicines after this procedure.
- Conventional surgery. Conventional surgery makes a new opening for the fluid to leave the eye. (See diagram on the next page.) Your doctor may suggest this treatment at any time. Conventional surgery often is done after medicines and laser surgeries have failed to control pressure. But in developing world it may be used as first option in case of poor patient follow up.Conventional surgery is about 60 to 80 percent effective at lowering eye pressure. If the new drainage opening narrows, a second operation may be needed. Conventional surgery works best if you have not had previous eye surgery, such as a cataract operation.Sometimes after conventional surgery, your vision may not be as good as it was before conventional surgery. Conventional surgery can cause side effects, including cataract, problems with the cornea, inflammation, infection inside the eye, or low eye pressure problems.
What are some other forms of glaucoma and how are they treated?
Open-angle glaucoma is the most common form. Some people have other types of the disease.
In low-tension or normal-tension glaucoma, optic nerve damage and narrowed side vision occur in people with normal eye pressure.
In angle-closure glaucoma, the fluid at the front of the eye cannot drain through the angle and leave the eye. The angle gets blocked by part of the iris. People with this type of glaucoma may have a sudden increase in eye pressure. Symptoms include severe pain and nausea, as well as redness of the eye and blurred vision. If you have these symptoms, you need to seek treatment immediately. This is a medical emergency. If your doctor is unavailable, go to the nearest hospital or clinic. Without treatment to restore the flow of fluid, the eye can become blind. Usually, prompt laser surgery and medicines can clear the blockage, lower eye pressure, and protect vision.
In congenital glaucoma, children are born with a defect in the angle of the eye that slows the normal drainage of fluid. These children usually have obvious symptoms, such as cloudy eyes, sensitivity to light, and excessive tearing. Conventional surgery typically is the suggested treatment, because medicines are not effective and can cause more serious side effects in infants and be difficult to administer. Surgery is safe and effective. If surgery is done promptly, these children usually have an excellent chance of having good vision.
Secondary glaucoma’s can develop as complications of other medical conditions. For example, a severe form of glaucoma is called neovascular glaucoma, and can be a result from poorly controlled diabetes or high blood pressure. Other types of glaucoma sometimes occur with cataract, certain eye tumors, or when the eye is inflamed or irritated by a condition called uveitis. Sometimes glaucoma develops after other eye surgeries or serious eye injuries. Steroid drugs used to treat eye inflammations and other diseases can trigger glaucoma in some people.
Pigmentary glaucoma occurs when pigment from the iris sheds off and blocks the meshwork, slowing fluid drainage.
Pseudo exfoliation glaucoma occurs when extra material is produced and shed off internal eye structures and blocks the meshwork, again slowing fluid drainage. Depending on the cause of this secondary glaucoma’s, treatment includes medicines, laser surgery, or conventional or other glaucoma surgery.
What research is being done?
Through studies in the laboratory and with patients, NEI is seeking better ways to detect, treat, and prevent vision loss in people with glaucoma. For example, researchers have discovered genes that could help explain how glaucoma damages the eye.NEI also is supporting studies to learn more about who is likely to get glaucoma, when to treat people who have increased eye pressure, and which treatment to use first.
What You Can Do
If you are being treated for glaucoma, be sure to take your glaucoma medicine every day. See your eye care professional regularly.
You also can help protect the vision of family members and friends who may be at high risk for glaucoma-African Americans over age 40; everyone over age 60, especially Mexican Americans; and people with a family history of the disease. Encourage them to have a comprehensive dilated eye exam at least once a year.
What should I ask my eye care professional?
You can protect yourself against vision loss by working in partnership with your eye care professional. Ask questions and get the information you need to take care of yourself and your family.
What are some questions to ask about my treatment?
- What is the treatment for my condition?
- When will the treatment start and how long will it last?
- What are the benefits of this treatment and how successful is it?
- What are the risks and side effects associated with this treatment?
- Are there foods, medicines, or activities I should avoid while I’m on this treatment?
- If my treatment includes taking medicine, what should I do if I miss a dose?
- Are other treatments available?
Loss of Vision
If you have lost some sight from glaucoma, ask your eye care professional about low vision services and devices that may help you make the most of your remaining vision
How should I use my glaucoma eye drops?
If eye drops have been prescribed for treating your glaucoma, you need to use them properly, as instructed by your eye care professional. Proper use of your glaucoma medication can improve the medicine’s effectiveness and reduce your risk of side effects. To properly apply your eye drops, follow these steps:
- Wash your hands.
- Hold the bottle upside down.
- Tilt your head back.
- Hold the bottle in one hand and place it as close as possible to the eye.
- With the other hand, pull down your lower eyelid. This forms a pocket.
- Place the prescribed number of drops into the lower eyelid pocket. If you are using more than one eye drop, be sure to wait at least 5 minutes before applying the second eye drop.
- Close your eye OR press the lower lid lightly with your finger for at least 1 minute.
For more information please our Ophthalmologists in our Eye Health Center