Patients with glaucoma suffer permanent damage to the optic nerve of the affected eye. The illness is commonly, but not always, associated with increased pressure in the eye and can progress to a complete lack of vision if left untreated. Elevated pressure in the eye without damage to the optic nerve is referred to as ocular hypertension and is a strong warning sign that a patient is at risk for glaucoma.

Multiple subtypes of the illness are recognised. All types are considered to be an optic neuropathy, and all involve a characteristic pattern of retinal ganglion loss. These subtypes are distributed into two broad categories.

Open angle glaucoma is a chronic illness that progresses at a much slower rate than its angle-closure counterpart. Angle-closure glaucoma has a very sudden onset and is often accompanied by pain in the eye. Open angle glaucoma does not usually express with pain, and it progresses so gradually that, without undergoing an eye exam, patients frequently do not realize that they have suffered a loss of vision until the illness is in advanced stages.

Vision lost to advanced glaucoma cannot be recovered by current treatment options. Glaucoma is the second most common cause of blindness on a worldwide scale, and is the leading cause of blindness among African Americans. Medical intervention can halt the progression of the illness if it is detected in its early stages.

Researchers believe that diabetes and hypertension significantly increase the risk for developing open angle glaucoma. This form of the illness accounts for approximately 90% of all glaucoma cases in the US, and the only signs of the illness are a gradual loss of vision and changes in the cup-to-disc ratio of the optic nerve.

Ocular hypertension is the largest risk factor, but the illness often expresses without any increased pressure in the eye. A statistical analysis of two million patients enrolled in a managed care network indicates that patients with hypertension alone are 17% more likely to develop open angle glaucoma. Patients with diabetes alone appear to be 35% more likely to develop the illness. Patients with both conditions appear to be 48% more likely to develop open angle glaucoma.

The study was conducted by researchers at the University of Michigan Kellogg Eye Center. Records used in the study covered the period of 2001 to 2007 and included only patients 40 years of age or older. The results indicate the importance of diabetic and hypertension management as well as the need for regular eye examinations.

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