Glaucoma – along with macular degeneration and cataracts – can steal your vision, especially as you age. Once your vision is gone, it cannot be restored.

Your best protection is regular, proactive monitoring of your eyesight by a vision care professional.

Some people are more at risk for development of glaucoma than others. According to the National Eye Institute, diabetics, those with a family history of glaucoma and African Americans over 50 should get a comprehensive dilated eye examination every year. Anyone over 60, especially Mexican Americans, should get this examination every other year. Medicare covers the cost for those at high risk.

What is glaucoma?

While macular degeneration indicates damage to a part of the retina and cataracts affect the lens, glaucoma results from damage to the optic nerve. This nerve transmits visual sensory data from the retina to the brain. Glaucoma can occur in one or both eyes.

A number of large studies indicate that eye pressure is the greatest risk factor for optic nerve damage. Excessive eye pressure results from impeded drainage of the fluid that naturally bathes the eye between the cornea and the iris (see diagram). In some people, the added pressure damages the optic nerve. This can lead to open-angle glaucoma, the most common form of the disease. Open-angle glaucoma develops slowly and has no pain. The only evident symptom is the slow narrowing of one’s field of vision. Peripheral (side) vision deteriorates first; eventually, straight ahead vision can close as well. Ultimately, all sight can be lost.

High blood pressure can also damage the optic nerve and cause glaucoma. People with high blood pressure must monitor their eye health.

Other forms of glaucoma are less common but equally dangerous.

Low- or normal-tension glaucoma refers to occurrences in individuals without high eye pressure. Sometimes, this is the result of low blood pressure.

In angle-closure glaucoma, an individual incurs a sudden increase in eye pressure due to fluid blockage and can suffer severe pain or nausea along with eye redness and blurred vision. Such symptoms constitute a medical emergency and require immediate attention. Otherwise, blindness can result.

Congenital glaucoma is seen in children born with a fluid blockage in the eye. The symptoms – cloudy eyes, sensitivity to light and excessive tearing – are usually obvious, and surgery usually corrects the problem.

Treatment

Among adults, immediate treatment in the early stages of glaucoma development can delay progression of the disease. One option is medication, and several are available. When properly administered and managed, they can lower eye pressure. Another option is laser trabeculoplasty, a kind of laser surgery that widens the openings in the mesh through which fluid drains from the eye. A third option is conventional surgery (trabeculectomy) which removes a small piece of tissue to create a channel for drainage.

The National Eye Institute provides a list of eye health organizations, many of which focus on glaucoma.

If you are a high risk individual or if you have noticed the narrowing of your vision, make an appointment to discuss the situation with your eye care provider as soon as possible.

[Steve Clark]