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Although glaucoma remains the second leading cause of blindness in the United States, considerable progress has been made in its management.
The disease can be controlled effectively and sight preserved for those patients whose condition is diagnosed and treated early.
Knowledge of the most common risk factors can help physicians identify glaucoma "suspects" and refer for sight saving (not sight restoration) treatment. Medical assistance in referring is critical because the disease, in many instances, presents no symptoms to alarm the patient.
Most persons with glaucoma, of course, are adults aged 40 or more. That is the patient category addressed by this article. An estimated two out of three persons with glaucoma in this mature age group exhibit elevated intraocular pressure when tested.
Pressure remains the foremost of all risk factors, yet the patient may not know it's anything out of the ordinary.
So insidious is the disease that the patient may experience gradual loss of vision - central and/or peripheral - and not realize it.
A test for intraocular pressure may even prove inconclusive because approximately one out of three persons with glaucoma suffers from the low-pressure type of glaucoma. In these cases, the pressure may be in the normal range of 12 to 21 millimeters of mercury.
The Optic Nerve
A definitive diagnosis can be made only by means of a thorough examination of the optic nerve. If the disease is present, it will be manifest in damage to nerve fibers and blood vessels.
Any long term decrease or interruption of blood flow to the optic nerve can cause ocular damage leading to glaucoma.
This would establish as candidates for glaucoma individuals with high or low blood pressure, blockage in the carotid, coronary disease or with a history of migraine headaches.
Diabetics and heavy smokers are at high risk because of the negative effects of both the disease and the habit on blood circulation.
Blacks are more at risk than whites because, for reasons unknown, their intraocular pressure is more difficult to control and they seem to sustain more nerve damage. They seem to scar faster after surgery, causing premature post-op drainage problems.
Anyone with a family history of glaucoma is 25% at risk of inheriting the disease. It should be noted also that individuals with myopia are more inclined than others to contract glaucoma.
In the normal eye, aqueous humor circulates freely through the anterior and posterior chamber. The fluid, produced constantly by the ciliary body, drains through the trabecular meshwork, back into the bloodstream.
Glaucoma develops when production of fluid increases, or filtration is no longer adequate. Pressure rises in the eye, causing damage to the optic nerve.
Three different treatment modalities are prescribed, each depending on how far the disease has progressed. Drops (sometimes pills) are the first and most conservative treatment method.
If drops do not ameliorate the condition, laser treatment is applied. Should that approach prove unsuccessful, surgery may be necessary. All three are designed to reduce intraocular pressure.
Approximately 2% of the adult population over age 40 suffers from glaucoma, much of which is stealing sight without warning symptoms. Highly effective treatment methods are available to manage the disease.
The challenge to physicians is to help identify individuals who, based on various characteristics and conditions, are prime candidates to have or contract glaucoma.
Individuals aged 40 or older and people at risk should have a professional eye examination by an eye doctor once a year. The checkup must include a thorough evaluation of the optic nerve. Anyone on regular medication, or with glaucoma in the family history, should see an eye doctor more often.
For such individuals, the optic nerve examination is even more important. Early detection and treatment will enable the ophthalmologist to control the disease and preserve what vision remains. Lost sight cannot be restored, but blindness can be prevented.