What is Glaucoma?
Glaucoma is a group of eye disorders that lead to progressive damage to the optic nerve. It usually happens when fluid builds up in the front part of your eye. That extra fluid increases the pressure in your eye, damaging the optic nerve. This loss of nerve tissue results in vision loss, beginning in the peripheral field and progressing towards the center leading to blindness. Glaucoma is a leading cause of blindness for people over 60 years old, but blindness from glaucoma can often be prevented with early treatment.
In the most common form of glaucoma, primary open-angle glaucoma, the fluid inside the eye does not drain efficiently. This slow increase in pressure causes painless progressive damage to the optic nerve and loss of nerve fibers. Not everyone with high eye pressure will develop glaucoma, and some people with normal eye pressure can develop glaucoma. When the pressure inside a person's eye is too high for a particular optic nerve, whatever that pressure measurement may be, glaucoma will develop.
Angle-closure glaucoma (also called “closed-angle glaucoma” or “narrow-angle glaucoma”) occurs when the iris is very close to the cornea, blocking the drainage channel in the eye much like a piece of paper sliding over a sink drain. When completely blocked, eye pressure rises very quickly and is called an acute attack. Symptoms include sudden blurred vision, severe eye pain, nausea/vomitting, headache, and colored rings or haloes around lights. It is a true eye emergency requiring immediate attention.
Risk factors for glaucoma include age over 40, although an infant (congenital) form of glaucoma exists. Those of African, Hispanic or Asian heritage, or those with a family history of glaucoma are at greater risk. Other risk factors include thinner corneas, significant far-sightedness or nearsightedness, long use of steroids, or a history of eye injury, diabetes, migraines, poor circulation or hypertension.
As glaucoma is usually painless, the diagnosis is often made during a routine eye exam. Testing includes not only a measure of your eye pressure, but a measurement of your peripheral visual field, pachymetry measurements of the thickness of the cornea and computerized measurements of the optic nerve and surrounding nerve fiber layer.
Because glaucoma damage is permanent, treatments aim to prevent further progression. Treatment methods include medications (eyedrops), office-based laser surgery or operating room surgery. This is a team effort requiring a consistent use of the prescribed medications and regular follow-up in the office.