GLAUCOMA
What is Glaucoma?
Glaucoma is the leading cause of blindness in the United States, especially for aging adults. Loss of sight from glaucoma is preventable if you seek early treatment.
Glaucoma (the sneak thief of eye sight) refers to certain eye diseases that affect the optic nerve which ultimately causes vision loss. The optic nerve transfers images we view to the brain to be coded and recognized. When the nerve is damaged, these images no longer have the ability to be detected. Glaucoma typically produces elevated pressure inside the eye, called intraocular pressure (IOP). The higher the pressure inside the eye, the greater the chance of damage to the optic nerve.
The optic nerve is like an electric cable containing a huge number of wires. Glaucoma can damage nerve fibers, causing blind spots to develop as each "wire" is affected.
Often, people don't notice these blind areas until much optic nerve damage has taken place. If the entire nerve is destroyed, blindness results. Early detection and treatment is important and is the key to preventing full optic nerve damage and blindness
What causes glaucoma?
There are many types of glaucoma and different theories for which is the exact cause. Although the definite cause is unknown, glaucoma is usually associated with an increase in the pressure inside the eye due to excess fluid. Four types of glaucoma include:
Primary open-angle glaucoma—The most common form of glaucoma. With glaucoma, the eye's drainage system becomes insufficient (usually occurring with age), which leads to an increased amount of fluid and gradual build up of pressure within the eye. Poor perfusion (blood flow), to the optic nerve is also thought to be a cause of glaucoma. Damage to the optic nerve is slow and painless and a large portion of vision can be lost before vision problems are noticed.
Angle-closure glaucoma—The less common form of the disease. This type of glaucoma occurs when the drainage angle (formed by the cornea and the iris) in the eye becomes blocked. As aging progresses, the lens of the eye becomes larger which pushes the iris forward, resulting in a narrowed space (drainage angle) between the iris and the cornea. When the drain becomes blocked, the aqueous fluid is unable to exit, resulting in a build up of fluid and an increase in eye pressure.
This type of glaucoma can have a sudden onset; so it is important to quickly seek treatment for the following symptoms in order to avoid blindness:
- Blurred vision
- Severe eye pain
- Headaches
- Rainbow halos around lights
- Nausea and vomiting
Secondary glaucoma—This type of glaucoma occurs as a result of an injury or other eye disease. It may be caused by a variety of medical conditions, medications, physical injuries, and eye abnormalities. Infrequently, eye surgery can be associated with secondary glaucoma.
Normal-tension glaucoma—In this form of glaucoma, eye pressure remains within what is considered to be the “normal” range; however, the optic nerve is damaged.
Who is at risk for glaucoma?
These factors may affect your chances of developing glaucoma:
- Age
- Near-sightedness
- African ancestry
- A family history of glaucoma
- Past injuries to the eyes
- A history of severe anemia or shock
Glaucoma Treatment Options
The most important form of treatment and preventative measures for glaucoma is a regular eye exam screening. Typically, it is recommended to have an eye screening every few years. This will differ depending on your family history, age, and ethnicity which may reflect your chances of developing glaucoma. In the early stages, glaucoma usually will not produce any noticeable symptoms; this is the most imperative time period for preventative measures and regular eye exams because once the optic nerve has been damaged, it cannot be reversed. Patients with glaucoma should have regular scheduled visits to their eye doctor and maintain a proper medication regimen in order to preserve vision.
Although nerve damage and visual loss from glaucoma cannot be reversed, symptoms of the disease can be controlled with proper medications and treatment. Treatments such as eye drops, laser surgery (Selective Laser Trabeculoplasty), and general surgery (Trabeculectomy) can help to decrease the ocular pressure caused by glaucoma and can assist in the slowing down or stopping of further nerve damage and vision loss.
Eye drops are usually the first choice for many patients in treating glaucoma. Drops are helpful in decreasing the ocular pressure by facilitating the aqueous fluid to properly drain. The better the drainage, the lesser the ocular pressure due to the decreased fluid build-up. There are many different types of eye drops used to treat glaucoma. Schedule an appointment with Hawaii Eye Institute to discuss the best eye care drops for you.
Trabeculectomy Surgery (filtration surgery) -Trabeculectomy Surgery involves creating a new “filter system” for the drainage of the aqueous fluid behind the eye. During the surgery, a piece of tissue from the drainage angle of the eye is removed which creates an opening. A flap of tissue taken from the sclera (the white of the eye) and the conjunctiva (clear covering over the sclera) is then positioned to partially cover the opening. This new opening allows fluid to drain out of the eye which results in avoiding the clogged drainage channel. Once the fluid begins to drain into the new opening, a bubble is formed by the tissue rising. This bubble is then examined at every eye examination to ensure that the new drainage opening is working.
Selective Laser Trabeculoplasty (SLT) - SLT is a form a laser surgery intended to lower the ocular pressure that is symptomatic in glaucoma. During the surgery, a laser is directed to the drainage tissue of the eye which starts a chemical and biological change to the tissue. This change results in opening the drain to allow the fluid to be released, resulting in decreased ocular pressure. The selective laser emits minimal heat energy, leaving less scar tissue and creating minimal pain to the patient. SLT is typically selected as a necessary surgery when eye drop medications are no longer lowering the ocular eye pressure.
Dr. Schmidt can help you determine which treatment options will work best for your glaucoma.
