Glaucoma is one of the leading causes of blindness in the U.S. It most often occurs in people over age 40. People with a family history of glaucoma, African Americans, and those who are very nearsighted or diabetic are at a higher risk of developing the disease.

Glaucoma is a slowly progressing disease of the optic nerve. There is progressive damage to the nerve fibers responsible for vision. An increase in intraocular pressure (IOP) is thought to be the cause for progressive nerve damage in the majority of patients with glaucoma.

The eye constantly produces aqueous. This clear fluid fills the space between the cornea and the iris known as the anterior chamber. The aqueous filters out of the anterior chamber through a complex drainage system. The delicate balance between the production and drainage of aqueous determines the eye’s intraocular pressure

An increase in intraocular pressure (IOP) can result from either a malformation or malfunction of the eye’s drainage structures. Left untreated, an elevated IOP causes irreversible damage to the optic nerve and retinal fibers resulting in a progressive, permanent loss of vision. However, early detection and treatment can slow, or even halt the progression of the disease.

Common types of glaucoma

Open Angle
Open angle glaucoma is the most common type of glaucoma. Even though the anterior structures of the eye appear normal, aqueous fluid builds within the anterior chamber, causing the IOP to become elevated. Left untreated, this condition may result in permanent damage to the optic nerve and retina. Eye drops or laser treatments such as ALT or SLT are generally used to lower the eye pressure. In some cases, surgery is performed if the IOP cannot be adequately controlled with other forms of treatment.

Acute Angle Closure
Acute angle closure is caused by an abnormality of the structures in the front of the eye. In most cases, the angle of the eye is narrower than normal, limiting the outflow of aqueous from the eye. When the outflow of aqueous is completely blocked, there is a sharp rise in IOP called an acute angle closure attack.

Patients with acute angle closure may experience severe eye pain accompanied by nausea, blurred vision, rainbows around lights, and a red eye. This problem is an emergency and should be treated by an ophthalmologist immediately. If left untreated, severe and permanent loss of vision can occur in a matter of hours.

Secondary Glaucoma
This type of glaucoma occurs as a result of another problem within the eye or systemic disease such as inflammation, trauma, previous surgery, diabetes, tumor, or medication. In this condition, both the glaucoma and the underlying problem must be treated.

Glaucoma cannot be prevented, but if diagnosed and treated early, it can be controlled. Unfortunately, vision lost to glaucoma cannot be restored. That is why annual eye examinations are recommended for people at risk for glaucoma.

Depending on your condition, your doctor may recommend more frequent examinations. A comprehensive glaucoma examination will include intraocular pressure measurement, corneal pachymetry, gonioscopy (examination of the angle structures), ocular examination, optic nerve evaluation, nerve fiber layer analysis, and visual field test.