GLAUCOMA

There are two types of glaucoma.  Open angle glaucoma and narrow angle glaucoma (also sometimes called closed angle glaucoma).  The following are descriptions of each along with information regarding symptoms, diagnosing and treating either with medication or surgical intervention.

Open-Angle Glaucoma

It is estimated that over two million Americans have some type of glaucoma and half of them do not know it. Ninety percent of glaucoma patients have open-angle glaucoma. Although it cannot be cured, it can usually be controlled. Vision loss may be minimized with early treatment. The eye receives its nourishment from a clear fluid that circulates inside the eye.

 
Fluid circulating inside eye

This fluid must be constantly returned to the blood stream through the eye's drainage canal, called the trabecular meshwork. In the case of open-angle glaucoma, something has gone wrong with the drainage canal. When the fluid cannot drain fast enough, pressure inside the eye begins to build.

Excess fluid builds pressure

This excess fluid pressure pushes against the delicate optic nerve that connects the eye to the brain. If the pressure remains too high for too long, irreversible vision loss can occur.

Excess fluid pressure pushes
against the optic nerve
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Symptoms of open-angle glaucoma:

• In the early stages, there are no symptoms. There is no pain or outward sign of trouble.
• Mild aching in the eyes
• Gradual loss of peripheral vision (the top, sides and bottom areas of vision)
• Seeing halos around lights
• Reduced visual acuity (especially at night, that is not correctable with glasses)

Who is at risk

Glaucoma can occur in people of all races at any age. However, the likelihood of developing glaucoma increases if you:

• are African American
• have a relative with glaucoma
• are diabetic
• are very nearsighted
• are over 35 years of age

Diagnosing open-angle glaucoma:

Everyone should be checked for glaucoma at around age 35 and again at age 40. Those considered to be at higher risk, including those over the age of 60 should have their pressure checked every year or two.

Your doctor will use tonometry to check your eye pressure. After applying numbing drops, the tonometer is gently pressed against the eye and its resistance is measured and recorded.	Tonometry is used to check your eye pressure
An ophthalmoscope can be used to examine the shape and color of your optic nerve. The ophthalmoscope magnifies and lights up the inside of the eye. If the optic nerve appears to be cupped or is not a healthy pink color, additional tests will be run.	An ophthalmoscope is used to examine your optic nerve
Perimetry is a test that maps the field of vision. Looking straight ahead into a white, bowl-shaped area, you'll indicate when you're able to detect lights as they are brought into your field of vision. This map allows your doctor to see any pattern of visual changes caused by the early stages of glaucoma. This test is done with a Humphrey Field Analyzer and is done in our clinic.     OCT or Optical Coherence Tomography uses light waves to create detailed images of the nerve fiber layer and optic nerve.  This helps your doctor diagnose and follow the progression of glaucoma.	Perimetry maps your field of vision OCT images the optic nerve
Gonioscopy is used to check whether the angle where the iris meets the cornea is open or closed. This helps your doctor determine if they are dealing with open-angle glaucoma or narrow-angle glaucoma.	Goniscopy is used to help to diagnose your glaucoma type

Treatments for open-angle glaucoma:

To control glaucoma, your doctor will use one of three basic types of treatment: medicines, laser surgery, or filtration surgery. The goal of treatment is to lower the pressure in the eye.

	Glaucoma medication comes in many forms

Medicines come in pill and eye drop form. They work by either slowing the production of fluid within the eye or by improving the flow through the drainage meshwork. To be effective, most glaucoma medications must be taken between one to four times every day, without fail. Some of these medications have some undesirable side effects, so your doctor will work with you to find a medication that controls your pressure with the least amount of side effects. Medicines should never be stopped without consulting your doctor, and you should notify all of your other doctors about the medications you are taking.

Argon Laser Trabeculoplasty  surgery treats the drainage canal. Requiring only numbing eye drops, the laser beam is applied to the trabecular meshwork resulting in an improved rate of drainage. When laser surgery is successful, it may reduce the need for daily medications.

Laser surgery can reduce
the need for daily medication

Filtration surgery is performed when medicines and/or laser surgery are unsuccessful in controlling eye pressure. During this microscopic procedure, a new drainage channel is created to allow fluid to drain from the eye.

Filtration surgery

Narrow-Angle Glaucoma (also called Closed-Angle Glaucoma)

Narrow-angle glaucoma is much more rare and is very different from open-angle glaucoma in that eye pressure usually goes up very fast. This happens when the drainage canals get blocked or covered over. The iris gets pushed against the lens of the eye, shutting off the drainage angle. Sometimes the lens and the iris stick to each other. This results in pressure increasing suddenly, usually in one eye. There may be a feeling of fullness in the eye along with reddening, swelling and blurred vision.

The drainage canals get blocked or covered over
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Symptoms of narrow-angle glaucoma:

The onset of acute narrow-angle glaucoma is typically rapid, constituting an emergency. If not treated promptly, this glaucoma produces blindness in the affected eye in three to five days. Symptoms may include:

• Inflammation and pain
• Pressure over the eye
• Moderate pupil dilation that's non-reactive to light
• Cloudy cornea
• Blurring and decreased visual acuity
• Extreme sensitivity to light
• Seeing halos around lights
• Nausea and/or vomiting

Causes of narrow-angle glaucoma:

• Defect in the eye structure
• Anything that causes the pupil to dilate -- dim lighting, dilation drops
• Certain oral or injected medications
• Blow to the eye
• Diabetes-related growth of abnormal blood vessels over the angle

Diagnosing narrow-angle glaucoma:

Everyone should be checked for glaucoma at around age 35 and again at age 40. Those considered to be at higher risk for narrow-angle glaucoma, including those who are Asian, farsighted or over the age of 60, should have their pressure checked every year or two.

Because of the rapid, potentially devastating results of narrow-angle glaucoma, you should seek medical treatment immediately if you experience any of the above symptoms.

During eye exams, your doctor will use tonometry to check your eye pressure. After applying numbing drops, the tonometer is gently pressed against the eye and its resistance is measured and recorded.	Tonometry is used to check your eye pressure
An ophthaolmoscope can be used to examine the shape and color of your optic nerve. The ophthalmoscope magnifies and lights up the inside of the eye. If the optic nerve appears to be cupped or is not a healthy pink color, additional tests will be run.	An ophthalmoscope is used to examine your optic nerve
Gonioscopy is used to determine whether the angle where the iris meets the cornea is open or closed, a key difference between open-angle glaucoma and narrow-angle glaucoma.	Goniscopy is used to help your glaucoma type

Treatment for narrow-angle glaucoma:

Laser iridotomy is a common treatment for narrow-angle glaucoma. During this procedure, a laser is used to create a small hole in the iris, restoring the flow of fluid to the front of the eye. In most patients, the iridotomy is placed in the upper portion of the iris, under the upper eyelid, where it cannot be seen.

Laser iridotomy

Filtration surgery is performed when medicines and/or laser surgery are unsuccessful in controlling eye pressure. During this microscopic procedure, a new drainage channel is created to allow fluid to drain from the eye.

Filtration surgery