Glaucoma affects about three million Americans, though many are unaware that they have it. Early on, there may not be any noticeable symptoms. The only way to detect glaucoma is with a comprehensive eye exam. Early detection and treatment may prevent irreversible loss of vision.
Worcester Ophthalmology Associates offers our patients ongoing comprehensive care for successful glaucoma management to prevent loss of vision. We offer medical exams, diagnostic testing, medical and laser treatments for glaucoma. More information regarding glaucoma, it's diagnosis and treatment follow below.
What is Glaucoma?
Glaucoma is a condition where fluid builds up inside the eye which increases pressure which can then damage the optic nerve. This can lead to a slow, progressive loss of vision. Usually there are no symptoms. There are several types of glaucoma, the most common being Open Angle Glaucoma. This occurs when the drainage canal (trabecular meshwork) becomes less efficient at draining fluid from the front eye. This fluid is called the aqueous humor. In open angle glaucoma the drain gets clogged and the eye pressure builds up. Increased eye pressure can lead to optic nerve damage. Optic nerve damage can occur at different pressures in different patients. There isn't a "right" eye pressure for everyone, even between your two eyes. Our doctors will establish a "target pressure" for you that he or she thinks will protect your optic nerve from further damage.
In its early stages, open angle glaucoma has no symptoms and your vision remains normal. As the optic nerve becomes damaged, blank spots may appear in the field of vision. These are usually not noticeable during everydayactivities until there is significant damage and the blank spots get larger.
Low Tension or Normal Pressure Glaucoma
In this condition, the optic nerve shows signs of glaucomatous damage but the eye pressure is in the "normal range". This diagnosis is usually made after there has been some optic nerve damage. These patients are usually treated the same way as those with open angle glaucoma.
Angle Closure Glaucoma
This type of glaucoma is an emergent condition and usually has symptoms. This occurs when the iris (colored part of your eye) is very close to the eye's drainage system and may block the outflow of aqueous from the front part of the eye. The eye pressure rises very quickly. People of Asian descent and those with farsightedness are more prone to this condition. The following symptoms suggest an acute attack and is a true emergency:
Sudden onset of blurred vision
Severe eye pain
You should contact your WOA physician immediately should these symptoms arise.
This type of glaucoma results from another eye condition or disease. Eye trauma, long-term steroid therapy or someone with an eye tumor may develop secondary glaucoma.
This is a very rare type of glaucoma that develops in infants and children and is often inherited. It can result in blindness if not diagnosed and treated early.
Who Is At Risk?
The following risk factors may be involved in the development of glaucoma:
Over age 40
Family history of glaucoma
African or Hispanic heritage
Asian heritage (at risk for angle closure glaucoma)
High eye pressure
Very farsighted or nearsighted
History of significant eye injury
History of diabetes, high blood pressure or poor circulation
Symptoms and Diagnosis
In open angle glaucoma there are no early symptoms. Only a comprehensive eye exam can let you know if you have glaucoma before irreversible loss of vision occurs. Angle closure glaucoma has severe symptoms and is a true medical emergency. You should call WOA immediately if you have sudden onset of eye pain associated with headache, nausea and vomiting and colored halos around lights.
During your comprehensive eye exam we will evaluate your eye pressure through tonometry. Most people have pressures between 10 and 21 millimeters of mercury but some people with pressures within this range can still develop glaucoma. On the other hand, those with elevated pressures may not be destined to get glaucoma. How much stress an optic nerve can endure varies from person to person.
If our doctors suspect that you might have glaucoma you can expect the following tests:
Your doctor inspects the optic nerve with an ophthalmoscope which magnifies the eye's interior. Your pupils may be dilated (enlarged) with eyedrops allowing for a better view of your optic nerve. A normal optic nerve has more than one million nerve fibers. As glaucoma progresses it causes the death of some of these fibers. A change in the nerve known as cupping occurs. As cupping increases blank spots appear in the field of vision.
This test allows your doctor to examine the eye's drainage system to determine if you have open angle glaucoma (where the drain is not working efficiently enough) or angle closure glaucoma (where the drain is at least partially blocked) or a dangerously narrow angle (where the drain may become blocked).
Perimetry (Visual Field Test)
This tests for blank spots in your vision.
This measures the thickness of the cornea, the clear window in front of the colored part of your eye (iris). This is a painless procedure where a probe is placed on the cornea to measure its thickness. A thin cornea may increase the risk of developing glaucoma.
Optic Nerve Photographs
Photos are usually obtained when initially diagnosed (baseline) and at periodic intervals thereafter to look for changes or progression of cupping.
Ocular Coherence Tomography (OCT)
A scan of the optic nerves looking for thinning (damage) in certain sectors or overall thinning with increased cupping. This is repeated at periodic intervals determined by your doctor.
Treatment of Glaucoma
Most glaucomas can be controlled but not cured. Damage caused by glaucoma cannot be reversed so the goal of treatment is to stop its progression. The most common treatments for glaucoma are eyedrops to reduce the eye's pressure either by decreasing fluid production or enhancing its outflow. This will prevent further loss of vision.
Depending on the severity of your condition and its response to medication, your doctor may recommend laser or incisional surgical procedures that will enhance fluid drainage and lower the eye pressure.
Preserving your vision requires teamwork between you and your doctor. We can prescribe treatment but it's up to you to follow through with your doctor's treatment plan. It's also important to keep your followup appointments to check for changes or progression. It is the only way to determine if your eye pressure is low enough to prevent progression.
- Laser Iridotomy
This is a surgical procedure in which a hole is placed in the peripheral iris (colored part of the eye) to relieve blockage of fluid access to the eye's drainage system. This procedure was first introduced in 1956. During this procedure the iris moves away from the eye's drain and proper drainage of the eye's fluid is enabled. This can be performed as a preventative measure before the drainage system becomes blocked (those patients with narrow angles). Laser iridotomy is usually performed in the fellow eye of patient who have had angle closure glaucoma as the probability of an angle closure in the second eye is about 50%. This is a painless procedure and only takes a few minutes to perform. Vision may be blurry for several hours after the procedure is done. Anti-inflammatory eyedrops are used for several days. A follow-up exam is done several weeks later.
- Selective Laser Trabeculoplasty (SLT)
This procedure is performed in our office. It is painless and only takes a few minutes. The eye is numbed with drops and the doctor holds a special lens on the eye to focus the laser on the eye's drainage system. It is used for the treatment of open angle glaucoma.
An SLT laser works at relatively low energy levels. It treats specific cells "selectively," leaving untreated portions of the drainage system intact. For this reason, SLT may be safely repeated. SLT offers an alternative to those who have been treated unsuccessfully with a different type of laser (argon) or with eyedrops. This laser opens the fluid channels in the eye's drain therebylowering the eye's pressure.
Long Terms Benefits of Glaucoma Laser Surgery
The length of time pressure remains lowered following laser surgery depends on the type of laser surgery, the type of glaucoma, age, race and many other factors. Some people may need the surgery repeated to better control the eye's pressure.
Medications Following Laser Surgery
Most people still need medication to control eye pressure following laser surgery. The laser surgery may lessen the amount of medication needed.
In general most patients can resume normal activities the next day after laser surgery. Your eye may be a bit irritated and your vision may be slightly blurry after the surgery. You probably should arrange for a ride home after your surgery.
Risks of Laser Surgery
As with any type of surgery, laser surgery can carry some risks. Some people experience a short-term increase in eye pressure soon after the surgery. Your eye pressure will be checked before you leave the office. Should it be elevated, anti-glaucoma medication will be prescribed for a few days.
We are now able to offer minimally invasive glaucoma surgery (MIGS) for patients with mild to moderate glaucoma in combination with cataract surgery. We have been pleased with the results of the iStent® procedure, which can be seen on the following video.
While we do not currently perform incisional surgery for more advanced glaucoma at Worcester Ophthalmology Associates, we can refer you to our trusted network of surgeons if you need this type of procedure.
This surgery creates a new drainage site to help filter internal fluid from the eye. Instead of going through the normal drainage site, the fluid is,drained into a new "space" that is created underneath the outer covering (conjunctiva) of the eye.
- Tube Shunt Surgery
This operation involves placement of a tube inside the eye to provide an alternative to bi-pass the eye's natural (and poorly functioning) drainage system.
- Surgery to Decrease the Amount of Fluid Made Inside the Eye
When other surgery fails to improve the flow of fluid from the eye, procedures to destroy the part of the eye that produces fluid can be done. These procedures are also used when scar tissue has formed after a previous surgery.