What is Glaucoma?
Glaucoma is the second leading cause of blindness in the United States.
Glaucoma is a disease that damages the optic nerve. Your optic nerve connects your eye to your brain, transporting light signals it receives from the retina to your brain. These signals are then interpreted as the images you see.
The optic nerve is made up of an average of 1.2 million nerve fibers (like an electric cable is made up of many wires). Glaucoma symptoms may not appear in its early stages, but when damage to the optic nerve fibers occurs, blind spots develop. These blind spots usually go undetected until the optic nerve is significantly damaged. Glaucoma can result in total blindness if the entire optic nerve is destroyed.
- The most common form of glaucoma is primary open-angle glaucoma. In this condition, the trabecular meshwork (the drainage channel) becomes less efficient at draining microscopic amounts of fluid from the eye; over time, this causes pressure within the eye to gradually increase. The increased pressure slowly and painlessly destroys the optic nerve fibers.
Compare this increased pressure to when you cross your legs for too long. The pressure on your legs cause them to “fall asleep” or go numb. The increased interocular pressure on your optic nerve does the same thing, causing your optic nerve fibers to go numb and eventually die.
Damage to the optic nerve can occur at different eye pressures among different patients. When a patient is at risk for future nerve damage, glaucoma treatment to achieve a target pressure is necessary to prevent further vision loss. Early detection and treatment are the keys to preventing blindness from glaucoma.
Regular complete eye examinations are critical to the detection of open-angle glaucoma because it often has no symptoms or obvious signs in its early stages. However, if left unchecked, it will cause the gradual and permanent loss of peripheral vision and finally central vision (permanent total blindness). Dr. Memmen will be able to detect any damage of your optic nerve during a complete exam before you may experience any symptoms due to severe optic nerve damage.
Open-angle glaucoma affects approximately 2.2 million Americans over the age of 40; another 2 million may have the disease and not know it.
Early stages of open-angle glaucoma can generally be treated with medication (eyedrops) or laser treatments. However, as the disease progresses, glaucoma surgery is often necessary. To learn more about glaucoma surgery, click here.
- Primary closed-angle glaucoma(or narrow-angle or angle-closure glaucoma) is a less common but much more aggressive form of glaucoma. Due to structural abnormalities in some patients’ eyes, the iris (the colored part of the eye) may come into contact with the cornea blocking the drainage angle of the eye, which then blocks the flow of aqueous humor. This can occur slowly (chronic) or suddenly (acute).
- Severe eye or brow pain
- Redness of the eye
- Blurred vision
- Appearance of colored rainbows or halos
- Nausea and vomiting
Untreated, closed-angle glaucoma can cause rapid and permanent vision loss in a matter of hours or a few days. This is why closed-angle glaucoma is considered a medical emergency and immediate treatment is necessary.
- Some patients can develop what is called normal-tension glaucoma. This occurs when glaucoma signs and symptoms (like optic nerve damage or blind spots in peripheral vision) are present in a patient where intraocular pressures are considered normal.
Normal-tension glaucoma is not well understood, but we do know that lowering eye pressure has been shown to slow progression of this form of glaucoma. The same treatment used for open-angle glaucoma is typically found successful in treating normal-tension glaucoma.
- Congenital and juvenille glaucoma are rare and start in infancy, childhood or adolescence. Like primary open-angle glaucoma, there are few, if any, symptoms in early stages because children’s eyes have the ability to stretch. Blindness can result if it is left untreated. Like most types of glaucoma, congenital and juvenille glaucoma run in families. So, if you have any family history of either forms of glaucoma, it’s best to have your child examined by Dr. Memmen to rule out any possible concerns.
- Secondary glaucoma results from other pre-existing diseases or eye conditions. Some causes of secondary glaucoma development are: tumors, long-term steroid therapy, eye injury or inflammation, or diabetes. Make an appointment with Dr. Memmen to discuss all of your questions.
- Family history of glaucoma
- Elevated eye pressures
- Past eye injury
- Certain optic nerve conditions
- Particular ethnic backgrounds, typically African, Hispanic, or Asian
- Health conditions that affect blood flow like: low blood pressure, migraines, or diabetes
Patients with a condition called Ocular Hypertension have higher than normal intraocular pressures, but no signs or symptoms of glaucoma like optic nerve damage or blind spots. They are, however, at a higher risk for developing glaucoma over time.
WARNING: Because glaucoma can have no symptoms in its early stages, having regular eye examinations by Dr. Memmen is critical to the diagnosis of glaucoma. Getting an annual eye exam from an optometrist is appropriate if you are young and have typically normal, healthy eyes.