What is Glaucoma?
Glaucoma is a disease of the optic nerve, which is made up of a million nerve fibers that transmit information to the brain. Glaucoma is the result of damage of these nerve fibers. The disease usually carries no symptoms, giving it the nickname “silent thief of sight.” It can, however, be detected in a comprehensive eye exam by testing intraocular pressure (IOP). An elevated IOP is often indicative of glaucoma. Left untreated, glaucoma leads to vision loss and eventually blindness. In fact, glaucoma is the second leading cause of blindness in the US.
Who’s at Risk for Developing Glaucoma?
The eye disease usually attacks people age 40 and older. Others at increased risk include:
- People with a family history of glaucoma
- African Americans and Hispanics are at a higher risk than Caucasians
- People with medical conditions such as diabetes, high blood pressure, and heart disease
- Individuals with a history of severe trauma to the eye
Types & Causes of Glaucoma:
Glaucoma is the result of elevated IOP; however, there are several theories about what ultimately causes the pressure to change within the eye.
- Primary Open-Angle Glaucoma – In the USA about 90% of all glaucoma cases are open angle. There are two theories as to the cause of open angle glaucoma. One theory suggests that glaucoma is the result of the eye’s drainage system losing effectiveness, thus leading to a gradual build of up fluid and pressure inside the eye, ultimately damaging the optic nerve. Another theory suggests that open angle glaucoma is the result of poor blood flow to the optic nerve. In either case, the damage occurs slowly with no pain or symptoms. It isn’t until significant damage has occurred that it becomes apparent.
- Angle-Closure Glaucoma – Very uncommon, this form is a medical emergency that can cause vision loss within 24 hours of onset. It is believe to be caused when the drainage angle, which is formed by the cornea and iris, becomes completely blocked causing a rapid increase of fluid and pressure.
- Secondary Glaucoma – this type of glaucoma is the product of another eye disease or optical injury that causes the IOP to elevate.
- Normal-Tension Glaucoma – With this form, eye pressure remains within a ‘healthy’ range, but nonetheless damage to the optical nerve is incurred. The cause is unknown.
Detection and Treatment of Glaucoma
We diagnose glaucoma during a comprehensive eye exam with a set of special tests including threshold visual fields testing, laser imaging and optic nerve photography. As glaucoma is a progressive disease we look for changes in appearance to the optic nerve and the amount of nerve tissue. This is one reason it is critical to have an annual exam, otherwise such changes may go unnoticed and untreated.
The goal with glaucoma treatment is to reduce the amount of intraocular pressure. This can be done with prescription therapeutic eye drops that must be taken regularly. Currently there are no cures for glaucoma, however continued treatment can help slow the progression of the eye disease and preserve sight.
Click here to learn more about our diagnostic vision testing services.