What is glaucoma?
Glaucoma is a series of diseases that result is damage to the optic nerves and eventual loss of vision. Glaucoma can affect anyone from newborn infants to the elderly. It is estimated that 3 million Americans have glaucoma. During this time, most people will NOT experience any symptoms. If left untreated, it can affect the vision and ultimately lead to permanent blindness. Glaucoma usually develops slowly over a period of years, but some rare forms can develop over hours.
Causes of glaucoma?
Inside the eye, a clear fluid, called the acqeous humor, is produced to nourish the structures within the eye. Normally, this fluid leaves the eye through a drainage system called the trabecular meshwork located in the angle of the eye. In glaucoma, this fluid fails to drain at a normal rate and the intraocular pressure (IOP) rises. When the pressure in the eye is too high (this varies from person to person) this damages the optic nerve, which is responsible for sending visual images from the eye to the brain. When the nerve cells die, permanent damage occurs.
Types of glaucoma?
Primary Open Angle Glaucoma
This is the most common type of glaucoma. In these cases, the drainage area inside the eye (the angle) changes for unknown reasons. This causes the fluid to drain too slowly out of the eye. As the fluid builds up, the pressure inside the eye gradually rises.
Acute Angle Closure Glaucoma
This is a rare form of glaucoma where the drainage angle suddenly becomes blocked. As the pressure inside the eye rises, blurred vision, severe pain, and occasionally nausea and vomiting can result. This is an ocular emergency. Prompt laser treatment may help resolve this problem.
Open Types of Glaucoma
Congenital glaucoma, narrow angle glaucoma, chronic angle closure glaucoma, and other types exist.
Glaucomais detected through a complete eye examination. While some patients may experience some symptoms, most patients do not learn they have the condition until they undergo a thorough eye exam. The only way to prevent vision loss is by early detection and treatment. Typically, the physician will check:
- Eye pressure
- Appearance of the optic nerve
- Visual field examination (periodically)
- Gonioscopy – looking at the drainage area of the eye (periodically)
- Examination of the nerve fiber layer (periodically)
- Three dimensional photographs of the optic nerve (periodically)
- Pachymetry – measurement of the corneal thickness
Many people think glaucoma and high eye pressure as being the same thing. In reality, the evaluation of the optic nerve and its function are more important. Patients can have glaucoma with seemingly normal eye pressure.
Symptoms of glaucoma
Early on, there are no symptoms. Vision stays normal and there is no pain. Over time and without treatment, people with glaucoma will experience a loss of peripheral vision, followed by a loss of central vision. Eventually without treatment, blindness can result.
Treatment for glaucoma
Once glaucoma has been diagnosed, treatment should begin as soon as possible to help minimize the risk of permanent vision loss. Glaucoma is not cured, but in most cases it can be controlled. Treatment focuses on relieving any symptoms that may be present and preventing further damage from occurring.
The vast majority of patients can be treated successfully with eye drops. Since glaucoma is a progressive disease, eye drops may need to be added or changed to maintain proper control of the pressure in the eyes. It is critical to use the drops daily as directed, and to have routine follow up eye examinations and testing with your eye doctor. Occasionally, if eye drops are not adequately controlling a patient’s glaucoma, other treatment options include:
- Selective Laser Trabeculoplasty (SLT) – this is done for patients with open angle glaucoma. The laser is focused on the trabecular meshwork and it stretches open the drainage area of the eye (the angle) to allow more fluid to drain from the eye and therefore lower the eye pressure. This is a highly effective procedure, but usually needs to be repeated every four or five years.
- Endocyclophotocoagulation (ECP) – uses a special laser and fiber optic system to treat areas inside the eye (ciliary processes). This procedure decreases the amount of fluid produced inside the eye and thereby lowers the pressure inside the eye. Typically, this surgery is done in combination with cataract surgery
- Laser Peripheral Iridotomy (LPI) – is used to equalize the pressure between the front and the back of the eye and to prevent this pressure imbalance from damaging the optic nerve. This treatment requires making a very small hole in the iris (the colored part of the eye), allowing the eye’s natural fluid to easily flow from the back to the front of the eye. This is done for patients with narrow or closed angles.
- Trabeculectomy (Filtering Microsurgery) – this is for patients who have not been helped by either eye drops or lasers. A new drainage passage is created by making a small hole and flap in the sclera (the white part of the eye) and creating a collection pouch for the ocular fluids.
- Tube Shunt Surgery – this is usually reserved for severe glaucoma cases. A thin, flexible tube (shunt) with a pouch is inserted into the eye to bypass the obstructed drainage system of the eye and lower the eye pressure.
- iStent Surgery – Today, there are many different treatment options available to help prevent vision loss caused by high eye pressure and glaucoma. If you have glaucoma and cataracts, iStent is a new, FDA-approved treatment that can significantly reduce eye pressure.
The iStent Trabecular Micro-Bypass stent is a new surgical therapy for mild to moderate glaucoma that is designed to improve fluid outflow in the eye to safely lower eye pressure. This may reduce or eliminate the need for glaucoma medications.
iStent is the smallest medical device ever approved by the FDA and is placed in your eye during cataract surgery. It is so small, you won’t be able to see or feel it after surgery but it will be continuously working to help reduce your eye pressure.
How can iStent help me?
Every day, you are probably taking one or more eye drops to control your eye pressure. By improving the outflow of fluid from your eyes, iStent works to constantly help control and lower your eye pressure. After implantation of the iStent, many patients are able to control their eye pressure with fewer or no medications. Controlling eye pressure is extremely important to reduce the risk for vision loss due to glaucoma. If you forget to take your eye drops or ‘skip a dose’, this can cause large changes in your eye pressure. Large changes in eye pressure can increases your risk for vision loss.
At Chico Eye Center, we were selected to be one of the first practices in the United States to perform the iStent procedure. Since then, we were the first practice in the world to combine the iStent surgery with ECP (a glaucoma laser procedure) to help treat patients with moderate to severe glaucoma.
For more information please visit the Glaukos website: www.glaukos.com