Glaucoma - Eye, Ear, Nose, and Throat Disorders

Glaucoma

According to the May 1994 issue of The Johns Hopkins Medical Letter , more than three million Americans are visually impaired because of glaucoma. Several different types of glaucoma have been identified, including chronic open-angle glaucoma, congenital glaucoma, acute angle-closure glaucoma, and secondary glaucoma, which is caused by secondary conditions such as hemorrhages, tumors, and inflammations. People with glaucoma usually experience hazy vision, eye and head pains, nausea, and rapid loss of vision. Glaucoma can occur in people of all ages, but is more likely to develop in people over the age of 35 years who are very nearsighted or diabetic.

Glaucoma occurs when extra fluid builds up inside an eye and presses against the optic nerve at the back of the eye. The build up usually results either from genetic factors or as part of the aging process. Normally a clear, transparent liquid called aqueous humor flows continually through the structures of the inner eye. If this flow becomes blocked, liquid pressure can build up against the optic nerves, which impairs their ability to transmit visual images to the brain.

In chronic open-angle glaucoma, the drainage channels of the aqeuous humor become smaller with age and clogged with deposits, which gradually increase pressure against the optic nerves. This is the most common type of glaucoma in adults, and many do not realize they have the condition because they assume it is a natural part of aging. This type of glaucoma causes a loss of peripheral vision, and if it is detected early by an opthalmologist, it can be treated with eye drops that decrease fluid build-ups in the aqueous humor.

Congenital glaucoma is caused by genetic abnormalities in the drainage openings of the eye at birth. It is quite rare and can only be reversed through surgery. Acute angle-closure glaucoma is caused by the iris pressing against the drainage canals in the inner eye. Fluid backs up and increases eye pressure which results in blurred vision, severe pain, and nausea. Patients with these symptoms should see an eye physician immediately as blindness can result within several days. Secondary glaucoma is caused by hemorrhages, tumors, or inflammations in the inner eye which block the drainage channels.