HURON OPHTHALMOLOGY, P.C.
Glaucoma
Glaucoma is one of the leading causes of blindness in the world. In the United States, approximately 1.4 million people are afflicted with the disease. If left untreated, glaucoma can cause progressive visual loss and blindness. This can usually be prevented if the glaucoma is detected and treated before significant damage occurs.
Glaucoma usually has no symptoms. In its early stages most people are unaware that they have the disease. Glaucoma, more than any other eye disease, requires early detection if treatment is to be successful.
The best way to prevent visual loss from glaucoma is through a medical eye examination every two to three years if you are over 40, and more frequently if you have risk factors for glaucoma (diabetes, family history of glaucoma, Afro-American heritage). At your examination, the eye pressure will be measured and the optic nerve examined. Other tests are ordered if there is a suspicion of glaucoma.
Once glaucoma is diagnosed, visual loss can usually be prevented or slowed with medical, laser or surgical treatment. Eye drops or pills are usually the first line of treatment, but if these are unsuccessful in halting glaucomatous damage, lasers or surgery may be recommended. Once vision is lost to glaucoma, it can never be regained.
WHAT IS GLAUCOMA?
Glaucoma is a disease where high pressure
inside the eye damages the optic nerve. The optic nerve is the major nerve to
the eye which delivers sight to the brain. Usually the higher the pressure, the
more damage to the optic nerve.
Early detection and treatment by your ophthalmologist is essential to prevent optic nerve damage and blindness from glaucoma.
WHAT ARE THE CAUSES OF GLAUCOMA?
The front of the eye is filled with a
clear liquid called aqueous humor. This liquid is produced behind the pupil of
the eye, and exits the eye through drainage channels called the trabecular
meshwork. If these drainage channels close or fail to function properly, the
fluid pressure within the eye may increase, and optic nerve damage and visual
loss may follow.
WHAT ARE THE DIFFERENT TYPES OF GLAUCOMA?
OPEN ANGLE GLAUCOMA:
This is the most common type of glaucoma in the United States. It is caused by
the drainage system of the eye failing to function properly creating a gradual
pressure build up within the eye. This increased eye pressure damages the optic
nerve, and is known as open angle glaucoma. Not all patients with elevated eye
pressure develop optic nerve damage. Some patients have what is known as ocular
hypertension, a condition where the patient's optic nerve can tolerate the
elevated eye pressure. Open angle glaucoma is painless, and causes damage so
gradually that patients are not aware of any visual loss until the optic nerve
is severely damaged.
ANGLE CLOSURE GLAUCOMA: Occasionally the
drainage area of the eye can suddenly become completely blocked. The eye
pressure builds up rapidly, and optic nerve damage and visual loss can occur
within a matter of hours. Whereas open angle glaucoma is usually asymptomatic,
angle closure glaucoma is not. The symptoms of angle closure glaucoma include:
Should you experience these symptoms, you must call your doctor immediately.
Unless treated, angle closure glaucoma can rapidly result in permanent
blindness. Angle closure glaucoma can occur in any individual, although it is
more common in people with Asian and Eskimo backgrounds.
LOW TENSION GLAUCOMA: Low or normal tension glaucoma is a rarer type of glaucoma
in which the pressure inside the eye is in the normal range, but the optic nerve
shows progressive damage.
CHRONIC ANGLE CLOSURE GLAUCOMA: This is a type of glaucoma where the drain of the eye gradually closes, and there are usually no symptoms.
HOW DO YOU KNOW IF YOU HAVE GLAUCOMA?
Routine eye examinations by your doctor are the best way to determine the
presence of glaucoma. During the eye examination, your doctor will perform
tonometry (measure your eye pressure) and ophthalmoscopy (evaluate for any optic
nerve damage). In addition, gonioscopy (looking at the drainage area of the eye)
and perimetry (testing the visual field, or peripheral vision of each eye) may
be performed if glaucoma is suspected.
If glaucoma is suspected or determined to be present, these tests will need to be repeated at periodic intervals.
WHAT ARE THE RISK FACTORS FOR GLAUCOMA?
High eye pressure is just one of the risk
factors for developing glaucoma. In addition to elevated eye pressure, other
important risk factors include:
Some patients are examined and found not have glaucoma, but are classified as glaucoma suspects. A glaucoma suspect means your risk of developing glaucoma is higher than the general population, and regular eye examinations are needed to detect any early signs of damage to the optic nerve.
WHAT IS THE TREATMENT OF GLAUCOMA?
There are several different ways to treat
glaucoma including medications, lasers and surgery. Your ophthalmologist will
determine which treatment is best to prevent further optic nerve damage and
visual loss.
MEDICINES
Glaucoma can often be controlled by
taking one or several eye drops. Pills can also be effective, although they are
not as commonly used as drops. Both the pills and eye drops decrease the
pressure in the eye by increasing drainage from the eye or by decreasing the
production of fluid within the eye.
For these medications to have a significant effect, it is imperative that they are taken regularly as prescribed.
Interestingly, eye medications can have side effects both in and around the eye, as well as in other parts of the body. If you experience any significant side effects that you think may be due to your eye medications, you should contact your ophthalmologist. In addition, you should let your other medical doctors know what eye medications you are taking.
Eye drops may have the following side effects:
Pills used to control glaucoma may sometimes cause:
LASER TREATMENT
Laser surgery to treat glaucoma is a safe and often very effective way to lower the eye pressure. The laser is usually used in one of two ways:
SURGERY
When medications and/or laser treatment
are ineffective in controlling glaucoma, surgery is needed. The most common type
of surgery performed, a surgical trabeculectomy, creates an alternate path for
the fluid to drain from the eye. This helps lower the eye pressure and prevents
further optic nerve damage and visual loss. Your doctor will discuss this
possibility with you when other options are not preventing progressive damage.
Serious complications from surgery can arise, but fortunately with modern micro-surgical techniques these are rare. Surgery is only recommended when the risk of visual loss from the glaucoma is greater than the surgical risks.
WHAT CAN YOU DO TO HELP?
Your ophthalmologist will suggest a
treatment plan for glaucoma, but only you can make sure that these treatment
recommendations are followed. Eye drops and pills need to be used precisely as
prescribed, and you should never stop or change glaucoma medications without
first consulting with your ophthalmologist.
HOW CAN VISUAL LOSS FROM GLAUCOMA BE
PREVENTED?
Regular eye examinations are essential to
detect glaucoma and help prevent permanent visual loss or blindness. You should
have an examination every 2 to 3 years if you are age 40 or older. A medical eye
examination should be performed at least every 1 to 2 years if you have risk
factors for glaucoma, which include: