Early detection is the best key to fight glaucoma
Dr. Sunil Thadani, seated, and technician Traci Carter consult during a patient's eye exam. They use a visual field machine that detects evidence of peripheral vision loss. (By Kevin G. Gilbert/Staff Photographer)
Fiction, nonfiction, magazines, newspapers. It doesn't matter.
She always has had a love of the written word, the Hagerstown woman said.
Now retired, Jackson, 68, has even more time to enjoy her favorite pastime.
But it makes her shudder to think something she took for granted could have been snatched away from her.
With no signs, no symptoms, Jackson was slowly losing her vision.
It was during a routine eye examination about three years ago that she discovered she had glaucoma — the same eye disease that caused her grandmother to go blind.
But unlike her grandmother, Jackson said she is lucky to have the benefit of the most current treatments, including eye drops, medications and laser procedures.
"My problem was caught before it became too serious," Jackson said. "But I still have to stay vigilant. I follow my doctor's directions religiously and I have very little field-of-vision loss."
More than three million Americans are affected by glaucoma — a group of eye diseases that gradually cause patients to lose their vision without warning.
But half of them don't yet know that they have a problem, according to the Glaucoma Research Foundation.
"In the most common form, there are virtually no symptoms," said Dr. Sunil Thadani, an ophthalmologist and cornea, cataract and refractive surgeon with Bergman Eye Center in Hagerstown. "Vision loss begins with peripheral or side vision, so if you have glaucoma, you may not notice anything until significant vision — as much as 40 percent — is lost."
Thadani said vision loss is caused by damage to the optic nerve that connects the light-gathering cells at the back of the eye to the brain.
The disease is the second leading cause of blindness in the world, he said, preceded by macular degeneration.
Thadani said there are two main types of glaucoma: primary open-angle glaucoma and angle-closure glaucoma.
Open-angle glaucoma is the most common form of the disease in the United States and usually develops very slowly as the eye's drainage canals gradually become clogged, raising the pressure in the eye. The resulting stress on the optic nerve can kill nerve fibers and destroy vision. Peripheral vision is usually affected first.
There are no early warning signs for open-angle glaucoma which is why it is often called "the sneak thief of sight."
Angle-closure glaucoma is caused by a sudden and severe rise in eye pressure. It occurs when the pupil enlarges too much or too quickly and the outer edge of the iris blocks the eye's drainage canals. It can be either acute or chronic.
Thadani said other types of glaucoma include secondary glaucoma, in which the eye pressure is elevated secondary to another disease process. Finally, there also is normal tension glaucoma, where there is optic nerve damage and visual field loss in the setting of a normal eye pressure.