Is a group of diseases of the optic nerve involving loss of retinal ganglion cells in a characteristic pattern of optic neuropathy. Although raised intraocular pressure is a significant risk factor for developing glaucoma, there is no set threshold for intraocular pressure that causes the disease. One person may develop nerve damage at a relatively low pressure, while another person may have high eye pressure for years and yet never develop damage. Untreated the disease leads to permanent damage of the optic nerve and resultant visual field loss, which can progress to blindness.

Glaucoma has been nicknamed "the silent sight thief". Worldwide, it is the second leading cause of blindness. It affects one in two hundred people aged fifty and younger and one in ten over the age of eighty.

People with a family history of glaucoma have about a six percent chance of developing the disease. Diabetics and African Americans are three times more likely than caucasians to develop primary open angle glaucoma. Asians are also susceptible and Inuit have a twenty to forty times higher risk than caucasians of developing the disease. Women are three times more likely than men to develop acute angle-closure glaucoma due to their shallower anterior chambers. Use of steroids can also cause hte disease.

There is increasing evidence of ocular blood flow to be involved in the pathogenesis of glaucoma. Current data indicate that fluctuations in blood flow are more harmful in glaucomatous optic neuropathy than steady reductions. Unstable blood pressure and dips are linked to optic nerve head damage and correlate with visual field deterioration.

A number of studies also suggest that there is a correlation, not necessarily causal, between the disease and systemic hypertension (i.e. high blood pressure). In normal tension glaucoma, nocturnal hypotension may play a significant role. On the other hand there is no clear evidence that vitamin deficiencies cause the disease in humans, nor that oral vitamin supplementation is useful in glaucoma treatment.

Those at risk of the disease are advised to have a dilated eye examination at least once a year.[


Diagnosis

Screening for glaucoma is usually performed as part of a comprehensive eye examination performed by ophthalmologists and optometrists. Assessment for the disease consists of two branches of tests: structural and functional. Structural analysis investigates glaucomatous changes in the eye's anatomical and physiological properties, whereas functional analysis involves psychometric testing to evaluate how glaucomatous disease has affected the eye's ability to function normally.


Treatment

Although intraocular pressure is only one major risk factors of glaucoma, lowering it via pharmaceuticals or surgery is currently the mainstay of treatment. In Europe, Japan, and Canada laser treatment is often the first line of therapy. In the U.S., adoption of early laser has lagged, even though prospective, multi-centered, peer-reviewed studies, since the early '90s, have shown laser to be at least as effective as topical medications in controlling intraocular pressure and preserving visual field. Some studies suggest that acupuncture can be very helpful in the treatment of the disease.


Drugs

Intraocular pressure can be lowered with medication, usually eye drops. There are several different classes of medications to treat glaucoma with several different medications in each class.

Each of these medicines may have local and systemic side effects. Adherence to medication protocol can be confusing and expensive; if side effects occur, the patient must be willing either to tolerate these, or to communicate with the treating physician to improve the drug regimen.

Poor compliance with medications and follow-up visits is a major reason for vision loss in glaucoma patients. Patient education and communication must be ongoing to sustain successful treatment plans for this lifelong disease with no early symptoms. Ophthalmologists have debated whether eye drops specifically for the disease should initially be started in both eyes or in just one eye (a binocular or monocular trial), but it appears either strategy is reasonable when properly interpreted.

The possible neuroprotective effects of various topical and systemic medications are also being investigated.


Surgery

Surgery is the primary therapy for those with congenital glaucoma. Both laser and conventional surgeries are performed. Generally, these operations are a temporary solution, as there is no cure for the disease as of yet.

For further help and information visit the International Glaucoma Association site via our Further information and Support Groups page.