Glaucoma is a leading cause of blindness in the United States, especially for older people. Loss of vision is preventable if treatment begins early enough.
It is a disease of the optic nerve. High pressure in the eye causes loss of optic nerve tissue. The higher the pressure in the eye, the greater the likelihood that damage to the optic nerve will occur. High pressure can not be felt, but is measured with a special instrument called a tonometer which should be a part of every routine eye exam.
Glaucoma rarely has symptoms before it affects vision. This is the reason that routine eye exams are critical. Early detection is the key to preventing vision loss or blindness from glaucoma.
Types of Glaucoma:
Chronic open-angle glaucoma is the most common type of glaucoma. It occurs with aging and is a result of poor drainage of the clear liquid (aqueous humor) from the inside of the eye. This liquid is not part of the tears that we normally have in our eyes. Poor draining increases pressure which causes optic nerve damage. It is so gradual and painless that you are unaware there is a problem until the nerve is badly damaged. This damage is not reversible. Over 90% of adult glaucoma patients have this type of glaucoma.
Angle-closure glaucoma is when the drainage system is completely blocked. This occurs very quickly and has symptoms that include blurred vision, severe pain in the eye, headache, rainbows or haloes around lights and nausea and vomiting. Angle-closure glaucoma is an emergency. If it is not treated immediately, blindness may result.
The risk factors for glaucoma include elevated eye pressure, age, myopia (nearsightedness), family history of glaucoma, diabetes, African ancestry, past injury to the eyes, and a history of severe anemia or shock.
Glaucoma is usually treated with eye drops that are taken several times a day. Laser surgery may be used for glaucoma. Sometimes a surgery called trabeculectomy is performed if the eye drops and/or laser do not control the pressure. This surgery creates a filter or “trap door” for fluid drainage out of the eye.