What is glaucoma?
Glaucoma is a disease that leads to damage of the optic nerve (the nerve that travels between each eye and the brain). The nerve damage may result in gradual, progressive loss of peripheral vision.
Can Glaucoma lead to blindness?
Yes. Vision loss from glaucoma can progress to loss of central vision if it is not treated. Glaucoma is one of the leading causes of blindness in this country.
What are the symptoms of glaucoma?
Most of the time glaucoma has no symptoms at all [except for angle-closure glaucoma (see below)]. Unfortunately, once vision is lost from glaucoma, it does not return and since vision loss usually occurs from the periphery towards the center, visual loss is often not noticed until you have very little vision left. This is why it is very important to get regular eye examinations by an ophthalmologist.
Why is my eye pressure measured?
Most types of glaucoma involve an elevated intraocular pressure (IOP). The eye has a certain inflation pressure which represents a balance between constant production and constant drainage of fluid within the eye. If the drainage area inside the eye becomes dysfunctional, IOP goes up and the high pressure eventually leads to optic nerve damage in the back of the eye resulting in visual loss.
Are there different types of glaucoma?
Primary open angle glaucoma is the most common form of the disease in the United States. This type of glaucoma occurs when the eye’s internal drainage canals become clogged over time.
Angle-closure (or narrow-angle) glaucoma occurs when the eye’s internal drainage area closes off and leads to elevated eye pressure. Sometimes, this can occur very acutely and cause sudden symptoms including blurry vision, severe pain in or around the eye, eye redness, halos or rainbows around lights, and even nausea or vomiting.
Secondary glaucoma can occur as a result of eye injury, diabetes, inflammatory eye diseases, tumors, chronic steroid use, or advanced cataracts.
Low-tension (normal tension) glaucoma occurs when eye pressure is normal or low. It is unclear how optic nerve damage occurs in this type of glaucoma.
Congenital glaucoma occurs in infants.
How is Glaucoma diagnosed?
Glaucoma can only be diagnosed through eye examinations. Oftentimes, the diagnosis of glaucoma can be made right away, but some individuals have borderline findings and are followed or treated as "glaucoma suspects". Glaucoma often runs in families, so if you are diagnosed with glaucoma, please recommend to all your family members that they get examined.
What tests are performed for Glaucoma?
- Intraocular pressure (IOP): pressure is applied to the eye by a small device or by a puff of air and the counter pressure is measured.
- Gonioscopy: a small lens is placed against the eye to inspect the eye’s internal drainage area.
- Pachymetry: a small device is used to measure the thickness of the central cornea. Depending on how thick or thin the cornea is, an adjustment may be made to the IOP reading.
- Dilated eye exam: a small lens is used by the doctor to examine the optic nerve for damage.
- Visual field testing: this test reveals a map of the complete field of vision.
- Optic nerve imaging: special cameras are used to monitor the health of the nerve fibers around the optic nerve.
How is glaucoma treated?
Glaucoma can be treated in a variety of ways. At the present time, there is no cure for glaucoma and unfortunately, once vision is lost from glaucoma, it cannot be recovered. The goal in treating glaucoma is to preserve the remaining vision and prevent blindness. Once detected, glaucoma requires long-term care and patients are advised to closely follow their doctor’s treatment plan.
Glaucoma is often treated with medications. Eye drops are used to reduce the intraocular pressure. Some eye drops reduce IOP by decreasing the amount of fluid made in the eye, while others help increase drainage of fluid from the eye.
Lasers treatment is often used to treat glaucoma. Laser trabeculoplasty (SLT or ALT) is performed to help reduce eye pressure. Laser iridotomy is often performed for patients with narrow-angle glaucoma.
Surgery in an operating room is sometimes needed to treat glaucoma. Surgical treatments aim to reduce intraocular pressure when medicines or laser treatment are insufficient.
Where can I get more information?
Please ask your doctor for more information about glaucoma. Handouts with more information are available to patients. Helpful websites include the following: