Glaucoma and Related Disorders

Overview

Glaucoma is a disease of the optic nerve. If untreated, glaucoma can lead to permanent loss of vision or even blindness. It is often diagnosed during a routine eye examination.

It is not fully understood why some individuals are more susceptible to glaucoma, but there are risk factors which increase a person’s risk of developing the disease. Age and race are important, but the single most important risk factor is higher intraocular pressure. Other risk factors include specific medical conditions, a family history of glaucoma, and other eye disorders which may predispose to glaucoma.

The Angle and Intraocular Pressure

The eye is a dynamic organ. It constantly produces clear fluid (aqueous) which keeps the eye in its proper shape and provides nutrients to intraocular structures such as the lens. This fluid is also constantly draining from the eye and into the vascular system through the trabecular meshwork in the angle.

Open Angles vs. Narrow Angles

There are different types of glaucoma. The most common type of glaucoma is open angle glaucoma. The angle appears open when examined, but the optic nerve has glaucoma damage and the pressure may or may not be higher than normal.

In some individuals the angle is narrow or closed. In these cases there is a risk that the intraocular pressure could increase if the trabecular meshwork (“drain”) were blocked. A sudden blockage of the angle is called an angle closure attack and this is a true emergency. The intraocular pressure can be extremely elevated and there is a risk of permanent loss of vision if treatment is not initiated.

Treatment

Treatment for glaucoma is dependent on the type of glaucoma. For open angle glaucoma, treatment usually entails lowering the intraocular pressure, typically with glaucoma drops or a laser procedure. Treatment is specific for each person, so a laser may be appropriate for one individual while drops may be used for another.

For patients with narrow angles, a laser can be used to help open up the angle and help to prevent an attack of angle closure. This procedure is called a laser iridotomy and is performed in an office or outpatient facility. A small hole is made in the peripheral iris, which is only able to be seen at a slit lamp exam.

Glaucoma Surgery

There are some patients in whom drops or laser procedures are not effective in controlling the intraocular pressure, or the glaucoma continues to worsen. In these cases glaucoma surgery may be recommended. Although there are different operations and devices, most glaucoma surgeries attempt to allow drainage of aqueous fluid from the eye to a space outside of the eye-wall and under the conjunctiva.

Follow up

Persons with glaucoma should be examined regularly and may require periodic glaucoma testing, such as visual fields or imagining of the optic nerve.