More than 3 million people in the United States have glaucoma. According to the National Eye Institute, the number will grow to more than 4.2 million by 2030.

David Wong, MD, is an ophthalmologist at the Kaiser Permanente Fresno Medical Center and a specialist in glaucoma for 20 years. Today he explains this chronic eye disease, treatment, and prevention.

What is glaucoma?

Glaucoma is a disease with optic nerve damage leading to progressive loss of peripheral vision. Patients with glaucoma usually but do not always have an elevation in eye pressure. There are more than 50 different types of glaucoma, but the primary kind is called open angle glaucoma, which results in progressive degeneration of the optic nerve.

What are some other types?

Normal pressure glaucoma is like open angle glaucoma except that the eye pressure is never elevated. Angle closure glaucoma is less common and presents more acutely with severe eye pain, blurring of vision, colored halos around lights, nausea, and vomiting.

Other less common types of glaucoma include congenital glaucoma, neovascular glaucoma, pseudoexfoliation glaucoma, and pigmentary glaucoma.

How is glaucoma diagnosed?

Patients are given a complete ocular history and examination with emphasis on examination of the anterior chamber angle, the optic nerve, and the visual field.

When does it first appear?

With congenital glaucoma, a child is born with the condition. But that is very rare. In the common open angle glaucoma, it usually appears starting in the 50s and up.

What is the treatment?

Treatment requires lowering of the eye pressure. This can be done with medications, laser, or surgery. It doesn’t cure the disease, but it does control it.

Is there a way to prevent it?

Angle closure glaucoma may be prevented with a prophylactic laser treatment if detected early.

Open angle glaucoma, which is the most common type of glaucoma, cannot be prevented. However, vision loss can be prevented with early detection and treatment in the majority of patients.

What advice do you have for patients who are first diagnosed with glaucoma?

Glaucoma is one of the leading causes of adult blindness as well as preventable blindness. The majority of patients do not have any symptoms until advanced stages of the disease. Therefore, an eye exam screening for glaucoma is recommended, especially if you have risk factors such as family history, eye injury or surgery, high eye pressures, use of steroids on a regular basis, or being African-American.

Are there misconceptions about glaucoma?

Yes. Patients sometimes say they don’t have any symptoms, so they don’t have glaucoma. But if they wait to get care until the disease is pretty advanced, then it is irreversible.

Another common fallacy is that a patient being treated with medications may say, ‘I don’t really see any benefit of medication, so why should I continue?’ Patients need to understand that treatment of glaucoma does not help them see better. Treatment does, however, prevent loss of vision. So, no new symptoms equal successful treatment.

This all points to the importance of educating people about glaucoma.