Glaucoma is called the “silent thief of vision” because it develops so slowly that you may not notice changes in your vision until the disease is late. Approximately 3 million people in the United States have glaucoma. Half of these people don’t know they have the disease.
How glaucoma affects your vision
Glaucoma is a group of eye diseases that damage the optic nerve, which sends visual information from the eye to the brain and is essential for good vision. Optic nerve damage is often related to intraocular pressure.
There are six common types of glaucoma:
- Open angle is the most common type. There are no symptoms in the early stages, but you may start to develop patchy blind spots in your side or peripheral vision. In later stages, these blind spots can affect your side vision.
- Acute angle-closure glaucoma is characterized by severe headaches, eye pain, blurred vision, halos or rings around lights, red eyes, and nausea.
- Normal pressure glaucoma has no symptoms in its early stages, and there are no signs as to why the optic nerve is still damaged despite normal eye pressure. Peripheral vision is reduced, and side vision may be lost.
- Symptoms of pigmentary glaucoma include halos around lights, blurred vision with movement, and loss of side vision. It may affect young, healthy people with myopia.
- Glaucoma also occurs in children, including infants. The baby may have dull or cloudy eyes, blink more often, or shed tears but not cry. Older children may experience symptoms such as blurred vision, increased myopia, and headaches.
- Pseudoexfoliation glaucoma is more common in northern European populations. People with this type of glaucoma develop white, powdery deposits on their lenses and iris.
Who is at risk for glaucoma?
Anyone can develop glaucoma, but African Americans over age 40, all people over age 60, and people with a family history of glaucoma or diabetes are at higher risk.
After cataracts, glaucoma is the leading cause of blindness among African Americans, who are six to eight times more likely to develop the disease than white people. African Americans tend to develop glaucoma about 10 years earlier than other ethnic groups. Therefore, it is important to have a comprehensive eye exam to check for glaucoma after age 35 or earlier if you have diabetes.
Risk factors for African Americans include:
- Over 40 years old
- High myopia
- have diabetes
- Have high blood pressure
- long-term use of steroids, such as those used to control asthma
Other ethnic groups, including Hispanics and Asians, are also at greater risk for the disease.
Among African Americans, genetic factors may be related to their higher prevalence of glaucoma, as well as cultural factors such as lower rates of regular eye exams and less access to vision care.
How to spot glaucoma
Regular comprehensive eye exams can detect glaucoma early before serious damage to the optic nerve occurs. Your age and the presence of symptoms determine the frequency of eye exams.
The following are recommended times for eye exams:
- Under 40 years old – every 5-10 years
- Ages 40–54—every 2–4 years
- Ages 55–64—every 1–3 years
- 65 years and older—every 1-2 years
Diagnosing glaucoma is not always easy, so your eye care professional will consider many factors before making a treatment decision. If your condition is difficult to diagnose or treat, you may be referred to a glaucoma specialist.
A typical comprehensive eye exam includes five tests to determine the health of your eyes by:
- Check the complete visual field, including lateral and central vision.
- The shape and color of the optic nerve is assessed by dilating the pupils.
- Measure the angle at which the iris of the eye meets the cornea.
- Measure intraocular pressure.
- Measure the thickness of the cornea.
Treat and prevent glaucoma
If you have glaucoma, the main treatments are prescription eye drops or laser treatments that can stop the condition from getting worse and protect your vision. If your doctor prescribes eye drops, be sure to take them even if you have no symptoms.
Although there is no cure for glaucoma, you can take steps to prevent the condition, including:
- Know your family history. Because glaucoma often runs in families, you may need more frequent eye exams.
- Schedule regular eye exams based on your age and symptoms.
- Wear safety goggles as glaucoma can occur from serious eye injuries, especially injuries from sports like baseball or boxing.
Consider participating in a glaucoma clinical trial, especially if you are African American, to help determine its cause and stimulate the development of new treatments and technologies.
Grant Heslep, MDis an ophthalmologist in Owatonna, Minnesota.