Glaucoma is perhaps the most well known of the major eye diseases or conditions. In fact, it is estimated that nearly three million people are diagnosed with glaucoma every year. However, many of our patients are still surprised to learn that there are actually multiple types of glaucoma. In the early stages of glaucoma, most people will have no visible symptoms or pain, and symptoms often occur gradually. Symptoms may also vary depending on which of these types of glaucoma you have.
Types of Glaucoma
Glaucoma is a group of conditions which are most typically caused by abnormally high pressure inside your eye, known as intraocular pressure. The source of this rise in pressure distinguishes one type of glaucoma from another.
Within your eye, a flow of aqueous fluid supplies nutrients and is drained from the eyeball, providing both an inflow and outflow of fluids. When this outflow is blocked, pressure builds up, and this pressure may damage and potentially kill off the optic nerve.
- Open angle glaucoma occurs when drainage channels around the entire eyeball gradually become blocked. Open angle glaucoma, which is also known as wide angle glaucoma, is the most common type. Although fluid does not drain properly, the eye structures look normal.
- Closed angle glaucoma, also known as acute- chronic- or narrow- angle glaucoma, occurs when fluids cannot pass through the pupil. With closed angle glaucoma, fluid is unable to drain because of the narrowness of the angle between the cornea and the iris. This causes a rapid buildup of eye pressure. This type of glaucoma is more common in Asia than in the West. It is also usually considered an emergency, so prompt treatment is essential.
Glaucoma is one of the leading causes of blindness in the United States. Additionally, almost any glaucoma doctor will often say that prevention is the best treatment, as symptoms may be gradual or unnoticeable until the disease is already at a late stage.
With open angle glaucoma, the most common type of glaucoma, peripheral vision gradually decreases in both eyes. Tunnel vision may occur in advanced stages, as well as eventual blindness.
With closed or acute angle glaucoma, symptoms may include eye pain, nausea and vomiting accompanying that pain, blurred vision and halos around lights, eye reddening, and sudden onset of visual disturbances as opposed to a more gradual process.
Risk Factors for Glaucoma
Although pressure in the eye leads to the progression of glaucoma, there are certain risk factors that increase the chances of developing glaucoma. These include:
- Previous damage to the eye
- Ethnic background
- African Americans who are older than 40
- Steroid use
- High levels of myopia
Diagnosis of Glaucoma
Because glaucoma can either gradually or quickly lead to vision loss, and it is symptom-free in the early stages, early diagnosis is critical. Most diagnoses occur during a routine eye exam or during an exam for another reason, such as macular degeneration or cataract.
During the comprehensive exam, the eye doctor may perform numerous tests. These tests measure intraocular pressure and corneal thickness, inspect the drainage angle, check for vision loss and test for optic nerve damage.
Treatment for Glaucoma
Because the damage cannot be reversed, early glaucoma treatment is important. If diagnosed early, treatment methods can prevent or slow vision loss. The focus of treatment is to lower the pressure in the eye. This may be done with oral medication, prescription eye drops, surgery, laser treatment or a combination of methods.
For acute angle glaucoma, emergency surgery may be necessary. This may include a laser procedure that opens a small portion of the iris to allow for the release of fluid, relieving the pressure.