Glaucoma is a sneaky disease.
You might even call it insidious. It creeps up slowly, unnoticed, quietly
stealing your sight a little at a time.
Glaucoma isn’t one disease, but a group of diseases that have at least
one trait in common – increased pressure within the eye.
Inside your eye, fluid (aqueous humor) is continuously produced to nourish
your lens and cornea. The fluid circulates from behind the colored portion of
your eye (the iris) through the opening at the center of your eye (pupil) and
into the space between your iris and cornea.
The fluid must be constantly drained. It drains at the point where your
iris and cornea meet through a meshwork, which acts as a valve to help
regulate pressure within your eye. When drainage is blocked, fluid builds up,
creating pressure. This progressively damages your optic nerve, which
transmits electrical impulses from your eye to your brain.
Peripheral vision goes first. Tunnel vision follows, and eventual total
blindness is possible. Of the more than 3 million Americans who have glaucoma,
80,000 are blind due to the disease.
Two types
- Open-angle glaucoma (chronic glaucoma). For unknown reasons, the
meshwork becomes blocked. This slows fluid outflow and raises pressure in
your inner eye. The pressure builds undetected over years, causing gradual
permanent damage to vision. About 90 percent of glaucoma is open-angle
glaucoma.
- Closed-angle glaucoma (acute glaucoma).
This occurs primarily in
older adults and those who are farsighted. It can cause blindness in 24 to
48 hours and needs immediate treatment. Closed-angle glaucoma tends to be
hereditary and is caused by a sudden increase in eye pressure.
