Facts About Glaucoma

Glaucoma refers to a group of eye diseases affecting the optic nerve, causing visual field loss and eventually blindness. It has been called the "sneaky thief of sight" since visual field loss usually happens gradually over a long period time. Many sufferers only recognize they have glaucoma when it is already in its advanced condition. Glaucoma ranks second as the leading cause of blindness worldwide.

Types of glaucoma

There are two major types of glaucoma: open-angle glaucoma (OAG) and acute angle-closure glaucoma (AACG). Also known as wide-angle glaucoma, OAG is the most common type of glaucoma. In this condition eye structures look normal, but eye fluid does not flow properly through the trabecular meshwork or the drain of the eye. AACG, also called narrow-angle or chronic angle-closure glaucoma, can result in a sudden elevation of pressure (intraocular pressure or IOP) inside the eye. Here, drainage is poor since the angle between the cornea and the iris is too narrow.

How is glaucoma detected?

Diagnosis for glaucoma requires an ophthalmologist to test a patient’s vision and examine his or her eyes through dilated pupils. Furthermore, the doctor will also perform tonometry, a procedure to examine eye pressure. The procedure also involves a visual field test to know whether there is loss of peripheral vision. Tests for glaucoma do not take long and are painless.

What are the symptoms of glaucoma?

For most sufferers of glaucoma, the first sign of the disease is the loss of side or peripheral vision, which may be undetected until the late stage of the disease. Occasionally, IOP can elevate to extreme levels, resulting in sudden eye pain, blurred vision, headache, or the appearance of halos around lights. If you experience any of the following signs and symptoms, go to your doctor immediately and seek medical care: tunnel vision (narrowing of vision), redness in the eye, nausea or vomiting, eye that appears hazy, pain in the eye, and vision loss.

Who is at risk for glaucoma?

People over the age 40 are at increased risk of getting glaucoma. But the disease can also occur in children, young adults, and even infants. It occurs more frequently among African-Americans at an earlier age, with greater loss of vision. You have a higher risk of glaucoma if you have a family history of glaucoma, diabetes, or poor vision. You are also at risk if you are of Japanese, Irish, Russian, Hispanic, Scandinavian, or Inuit descent. Lastly, you are more likely to get glaucoma if you take systemic corticosteroid medications like prednisone.

Prevalence and incidence

Glaucoma affects about 2 million adults 40 years and older in the United States (1.57 million Whites and around 398,000 Blacks). This accounts for 1.86% of the US population in this age range. Because of the rapidly aging population in the country, the number is expected to double to 3.6 million in 2020. On the other hand, AACG affects 1-40 times for every 1000 Americans depending on their ethnicity. It occurs in about 1 in 1000 Caucasians, 2-4 for every 100 Eskimos, and 1 in 100 Asians.

Can glaucoma be treated?

Glaucoma can be treated using prescription eye drops; reducing the buildup of eye fluid or increasing its outflow, laser surgery; slightly increasing the outflow of the fluid in OAG or eliminating fluid blockage in AACG, or microsurgery; a new channel drains the fluid, thus reducing IOP.