Glaucoma refers to a group of eye conditions that lead to damage to the optic nerve, the nerve that carries visual information from the eye to the brain.
In many cases, damage to the optic nerve is due to increased pressure in the eye, also known as intraocular pressure (IOP).
Glaucoma is the second most common cause of blindness in the United States. There are four major types of glaucoma:
The front part of the eye is filled with a clear fluid called aqueous humor. This fluid is always being made in the back of the eye. It leaves the eye through channels in the front of the eye in an area called the anterior chamber angle, or simply the angle.
Anything that slows or blocks the flow of this fluid out of the eye will cause pressure to build up in the eye. This pressure is called intraocular pressure (IOP). In most cases of glaucoma, this pressure is high and causes damage to the major nerve in the eye, called the optic nerve.
Open-angle (chronic) glaucoma is the most common type of glaucoma.
Angle-closure (acute) glaucoma occurs when the exit of the aqueous humor fluid is suddenly blocked. This causes a quick, severe, and painful rise in the pressure within the eye (intraocular pressure).
Congenital glaucoma often runs in families (is hereditary).
Secondary glaucoma is caused by:
An eye exam may be used to diagnose glaucoma. The doctor will need to examine the inside of the eye by looking through the pupil, often while the pupil is dilated. The doctor will usually perform a complete eye exam.
Checking the intraocular pressure alone (tonometry) is not enough to diagnose glaucoma because eye pressure changes. Pressure in the eye is normal in about 25% of people with glaucoma. This is called normal-tension glaucoma. There are other problems that cause optic nerve damage.
Tests to diagnose glaucoma include:
The goal of treatment is to reduce eye pressure. Depending on the type of glaucoma, this is done using medications or surgery.
Open-angle glaucoma treatment:
Most people with open-angle glaucoma can be treated successfully with eye drops. Most eye drops used today have fewer side effects than those used in the past. You may need more than one type of drop. Some patients may also be treated with pills to lower pressure in the eye. Newer drops and pills are being developed that may protect the optic nerve from glaucoma damage.
Some patients will need other forms of treatment, such as a laser treatment, to help open the fluid outflow channels. This procedure is usually painless. Others may need traditional surgery to open a new outflow channel.
Angle-closure glaucoma treatment:
Acute angle-closure attack is a medical emergency. Blindness will occur in a few days if it is not treated. Drops, pills, and medicine given through a vein (by IV) are used to lower pressure. Some people also need an emergency operation, called an iridotomy. This procedure uses a laser to open a new channel in the iris. The new channel relieves pressure and prevents another attack.
Congenital glaucoma treatment:
This form of glaucoma is almost always treated with surgery to open the outflow channels of the angle. This is done while the patient is asleep and feels no pain (with anesthesia).
With good care, most patients with open-angle glaucoma can manage their condition and will not lose vision, but the condition cannot be cured. It's important to carefully follow up with your doctor.
Rapid diagnosis and treatment of an attack is key to saving your vision. Seek emergency care immediately if you have symptoms of an angle-closure attack.
Early diagnosis and treatment is important. If surgery is done early enough, many patients will have no future problems.
Call your health care provider if you have severe eye pain or a sudden loss of vision, especially loss of peripheral vision.
Call for an appointment with your health care provider if you have risk factors for glaucoma and have not been screened for the condition.
There is no way to prevent open-angle glaucoma, but you can prevent vision loss from the condition. Early diagnosis and careful management are the keys to preventing vision loss.
Most people with open-angle glaucoma have no symptoms. Everyone over age 40 should have an eye examination at least once every 5 years, and more often if in a high-risk group. Those in high-risk groups include people with a family history of open-angle glaucoma and people of African heritage.
People at high risk for acute glaucoma may opt to undergo iridotomy before having an attack. Patients who have had an acute episode in the past may have the procedure to prevent a recurrence.
Open-angle glaucoma; Chronic glaucoma; Closed-angle glaucoma; Congenital glaucoma; Angle closure glaucoma