What are the common types of glaucoma?
What are the risk factors for glaucoma?
Although glaucoma is most common in adults over the age of 40, susceptibility is not determined by age alone. There is a genetic component, and those with a family history of the disease, as well as African-Americans, are at increased risk. Studies have shown people at greater risk for glaucoma may fit one or more of the following criteria:
Since early detection is critical to avoiding permanent loss of vision, people with any of these risk factors should have regular examinations by an ophthalmologist every one or two years.
People in the general population should have a glaucoma evaluation every two or three years after the age of 40, and every one or two years after the age of 60.
What is involved in a glaucoma evaluation?
We perform a comprehensive glaucoma screening that consists of three non-invasive, pain-free procedures:
What is the treatment for glaucoma?
Glaucoma treatment seeks to decrease intraocular pressure and prevent damage to the optic nerve. Different types of glaucoma require different therapies. At the beginning of treatment, the doctor will generally recommend medication or a combination of medications for the specific condition. Therapies may include:
Glaucoma operations have been shown to be safe and effective surgical treatments. The two main types of surgical procedures are tube shunt surgery and trabeculectomy. Both tube shunt surgery and trabeculectomy lower the intraocular pressure by creating a route for aqueous fluid to drain out of the eye.
Drainage implants --- A tube inserted into the eye shunts aqueous fluid to a silicone plate that is attached to the sclera (the white portion of the eye).
Trabeculectomy --- An opening, surgically created under a trap-door incision in the sclera, allows aqueous fluid to drain. Anti-scarring medications such as mitomycin or flurouracil are commonly applied at the operation site to reduce scarring that could close the trap door.
Frequently Asked Questions About Glaucoma
Is blindness due to glaucoma preventable?
Regular examinations are the key to preventing loss of vision due to glaucoma. Although there is no way to reverse damage, if glaucoma is diagnosed and treated early, blindness is almost always preventable.
What are the symptoms of glaucoma?
Although the blindness associated with this disease is preventable, more than one million people in the United States have some glaucoma-related vision loss. In most cases, glaucoma is asymptomatic (has no symptoms). By the time an individual experiences decreased vision, the disease is frequently in its latter stages. Since early warning signs of glaucoma are rare, it is important --- especially for those at risk --- to have medical eye examinations at appropriate intervals, as described in this section.
Symptoms depend on the type of glaucoma the individual has.
The eye has an internal pressure created by production of a clear fluid called aqueous humor. This fluid circulates through the eye and exits through the anterior chamber angle and ultimately drains into the blood stream. In glaucoma, the aqueous humor outflow is obstructed, resulting in increased eye pressure and, eventually, optic nerve damage.
What research is being conducted for glaucoma patients?
Medical and surgical treatments are being researched. Many national clinical trials are ongoing or have been completed, including the Ocular Hypertension Study (OHTS), the Advanced Glaucoma Intervention Study (AGIS), the Collaborative Normal Tension Glaucoma Study (CNTGS), and the Collaborative Initial Glaucoma Treatment Study (CIGTS).
New medical treatments for glaucoma that affect blood flow to the optic nerve, intraocular pressure, and survival of retinal ganglion cells are being investigated. Although decreasing intraocular pressure is the only treatment shown to slow progression of most forms of glaucoma, other treatments to help retinal ganglion cells survive are actively being tested. Combinations of different pre-existing glaucoma medications are in clinical trials as well.
Different technologies are being compared for the early detection of glaucoma including retinal nerve fiber and other structural analysis through techniques such as optical coherence tomography. Different functional tests of retinal ganglion cell function including short wavelength automated perimetry (SWAP) are also actively being studied for early detection of visual field loss.
Surgical techniques such as selective laser trabeculoplasty (SLT) and non-penetrating types of filtering surgeries are being compared to conventional treatments such as argon laser trabeculoplasty, trabeculectomy and drainage implants. New glaucoma drainage implants that are possibly easier to implant or provide better pressure control are in the design and clinical trial phases of development.
Probably one of the most exciting areas of glaucoma research is in the area of genetics. Studies of families with glaucoma have identified several genes involved in glaucoma and the function of these genes and the search for more genes are ongoing. These studies will hopefully provide scientists with new targets to treat glaucoma in addition to intraocular pressure and possibly allow for genetic screening for patients at risk of developing glaucoma.
Other Glaucoma Resources