When diagnosing glaucoma, a healthcare provider will typically do a comprehensive eye exam that includes a visual acuity test, visual field test, and dilated eye exam. Although many people are familiar with the common "air puff" test conducted at regular eye exams, most are not aware that this test alone cannot detect glaucoma.
An Introduction to a Glaucoma Diagnosis
Many people may know of the "air puff" test or other tests used to measure eye pressure during an eye examination. However, this test alone cannot detect glaucoma; while elevated eye pressure means that you are at risk for developing glaucoma, it does not necessarily mean that you have it (see Glaucoma and Eye Pressure). A person has glaucoma only if the optic nerve is damaged. If you have increased eye pressure but no damage to the optic nerve, you do not have glaucoma.
Most often, in order to diagnose glaucoma, your doctor will ask you a number of questions (medical history) and perform a comprehensive eye exam.
Eye Exam for Diagnosing Glaucoma
A glaucoma diagnosis is made through a comprehensive eye exam that includes:
•Visual acuity test. This eye chart test measures how well you see at various distances.
•Visual field test. A visual field test measures your side (peripheral) vision. It helps your eye care professional tell if you have lost side vision, a sign of glaucoma.
•Dilated eye exam. For this eye exam, drops are placed in your eyes to widen, or dilate, the pupils. Your eye care professional uses a special magnifying lens to examine your retina and optic nerve for signs of damage and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
•Tonometry. A tonometry is an instrument that measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
•Pachymetry. For a pachymetry, a numbing drop is applied to your eye. Your eye care professional uses an ultrasonic wave instrument to measure the thickness of your cornea.
Thursday, February 25, 2010
Glaucoma.
Glaucoma is a group of diseases characterized by high pressure within the eye, damage to the optic nerve, and loss of peripheral vision. It is a leading cause of blindness in the United States. Although there is no cure, there are several treatment options, including medication, laser surgery, and traditional surgery, that can control the condition.
An Introduction to Glaucoma
Glaucoma is a group of diseases sharing certain features, commonly including high pressure within the eye (intraocular pressure), damage to the optic nerve, loss of peripheral (side) vision, and possibly blindness.
Nearly 3 million people have glaucoma. Approximately 80,000 Americans become blind each year because of it. The condition causes another 900,000 people to lose partial vision.
However, with early treatment, you may be able to protect your eyes against serious vision loss.
Understanding the Eye
The cornea is the clear outer covering of the eye. Separating it from the iris (the colored part) is the anterior chamber, a space filled and inflated by aqueous humor. This clear fluid (unrelated to the tears which bathe the outside surface of the cornea) starts in the ciliary body just behind the iris. It circulates in the anterior chamber, nourishing the eye's delicate tissue and keeping it from collapsing. To maintain equilibrium, the aqueous humor drains through a porous tissue in the angle in front of the iris, where it meets the cornea, called the trabecular meshwork.
If the aqueous humor cannot drain properly, either because the drainage canals become clogged (as in open angle glaucoma) or because the iris is pushing against the cornea (as in angle closure glaucoma), it backs up, putting pressure on the gel in the vitreous cavity at the center of the eye. Eventually, the building pressure affects the delicate optic nerve at the rear of the eye. Since the optic nerve transmits visual images to the brain, any damage to it reduces vision.
The optic nerve is a bundle of more than one million nerve fibers. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.
An Introduction to Glaucoma
Glaucoma is a group of diseases sharing certain features, commonly including high pressure within the eye (intraocular pressure), damage to the optic nerve, loss of peripheral (side) vision, and possibly blindness.
Nearly 3 million people have glaucoma. Approximately 80,000 Americans become blind each year because of it. The condition causes another 900,000 people to lose partial vision.
However, with early treatment, you may be able to protect your eyes against serious vision loss.
Understanding the Eye
The cornea is the clear outer covering of the eye. Separating it from the iris (the colored part) is the anterior chamber, a space filled and inflated by aqueous humor. This clear fluid (unrelated to the tears which bathe the outside surface of the cornea) starts in the ciliary body just behind the iris. It circulates in the anterior chamber, nourishing the eye's delicate tissue and keeping it from collapsing. To maintain equilibrium, the aqueous humor drains through a porous tissue in the angle in front of the iris, where it meets the cornea, called the trabecular meshwork.
If the aqueous humor cannot drain properly, either because the drainage canals become clogged (as in open angle glaucoma) or because the iris is pushing against the cornea (as in angle closure glaucoma), it backs up, putting pressure on the gel in the vitreous cavity at the center of the eye. Eventually, the building pressure affects the delicate optic nerve at the rear of the eye. Since the optic nerve transmits visual images to the brain, any damage to it reduces vision.
The optic nerve is a bundle of more than one million nerve fibers. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.
Glaucoma Medications.
There are many types of medications that can be used for glaucoma, such as beta-blockers, miotics, and adrenergic agonists. These drugs work by either slowing the flow of fluid into the eye or by helping to improve fluid drainage. Medications can effectively stop the progress of the eye condition; however, as the eye develops tolerance to the medicine, it may be necessary to increase dosages as needed.
Medications for Glaucoma: An Overview
Glaucoma medicines are designed to either reduce pressure by slowing the flow of fluid into the eye or help to improve fluid drainage.
While these drugs can effectively stop the progress of glaucoma, increasing dosages may be needed as the eye develops tolerance to the medication.
Medications to treat glaucoma are serious medicine, not to be confused with over-the-counter eye drops for easing common eye irritations. In order to control the disease, glaucoma drugs are taken for life.
There are several different classes of medicine used for glaucoma (available in the form of pills or eye drops). Some of these classes of medications include:
•Beta-blockers
•Miotics
•Adrenergic agonists
•Carbonic anhydrase inhibitors.
Beta-Blockers
The most popular glaucoma medication, Timoptic® (timolol maleate) is a beta-blocker eye drop. Usually taken twice daily, beta-blockers decrease production of aqueous humor.
These medicines may have side effects on the nerves, digestion, vision, skin, respiration, and heart of some individuals. Side effects may include:
•Lowered pulse rate
•Lower blood pressure
•Worsening of asthma
•Fatigue
•Breathing problems.
Miotics
Timoptic has a century-old predecessor, pilocarpine, that requires more frequent use to do its job, increasing drainage of aqueous fluid in both open and closed angle glaucoma. Pilocarpine is a miotic, designed to increase aqueous fluid drainage. Because these glaucoma medications work by making the pupil smaller, they can result in dim vision and may increase the risk of cataracts.
Medications for Glaucoma: An Overview
Glaucoma medicines are designed to either reduce pressure by slowing the flow of fluid into the eye or help to improve fluid drainage.
While these drugs can effectively stop the progress of glaucoma, increasing dosages may be needed as the eye develops tolerance to the medication.
Medications to treat glaucoma are serious medicine, not to be confused with over-the-counter eye drops for easing common eye irritations. In order to control the disease, glaucoma drugs are taken for life.
There are several different classes of medicine used for glaucoma (available in the form of pills or eye drops). Some of these classes of medications include:
•Beta-blockers
•Miotics
•Adrenergic agonists
•Carbonic anhydrase inhibitors.
Beta-Blockers
The most popular glaucoma medication, Timoptic® (timolol maleate) is a beta-blocker eye drop. Usually taken twice daily, beta-blockers decrease production of aqueous humor.
These medicines may have side effects on the nerves, digestion, vision, skin, respiration, and heart of some individuals. Side effects may include:
•Lowered pulse rate
•Lower blood pressure
•Worsening of asthma
•Fatigue
•Breathing problems.
Miotics
Timoptic has a century-old predecessor, pilocarpine, that requires more frequent use to do its job, increasing drainage of aqueous fluid in both open and closed angle glaucoma. Pilocarpine is a miotic, designed to increase aqueous fluid drainage. Because these glaucoma medications work by making the pupil smaller, they can result in dim vision and may increase the risk of cataracts.
Acute Glaucoma.
Acute glaucoma is a less common (but very serious) form of glaucoma. It is characterized by increased eye pressure, intense pain, and rapid damage to the optic nerve. Without immediate treatment during an attack, this condition can quickly lead to vision loss. People who have farsightedness, diabetes, or a family history of glaucoma are at a higher risk of developing it.
What Is Acute Glaucoma?
Acute glaucoma is one of the many different glaucoma types (see Types of Glaucoma). It is much less common than chronic glaucoma (also known as open angle glaucoma). However, acute glaucoma is very serious because it can cause rapid damage and loss of vision; it can also erupt in violent attacks and intense pain, rather than emerging subtly.
This condition occurs in less than 10 percent of glaucoma cases.
Other names for acute glaucoma include:
•Closed angle glaucoma
•Angle closure glaucoma
•Narrow angle glaucoma.
How Acute Glaucoma Affects the Eye
The cornea is the clear outer covering of the eye. Separating it from the iris (the colored part) is the anterior chamber, a space filled and inflated by aqueous humor. This clear fluid (unrelated to the tears that bathe the outside surface of the cornea) starts in the ciliary body just behind the iris. It circulates in the anterior chamber, nourishing the eye's delicate tissue and keeping it from collapsing.
To maintain equilibrium, the aqueous humor drains through a porous tissue in the angle in front of the iris, where it meets the cornea, called the trabecular meshwork.
If the aqueous humor cannot drain properly because the iris is pushing against the cornea (as in acute glaucoma), it backs up, putting pressure on the gel in the vitreous cavity at the center of the eye. Eventually, the building pressure affects the delicate optic nerve at the rear of the eye. Since the optic nerve transmits visual images to the brain, any damage to it reduces vision.
The optic nerve is a bundle of more than one million nerve fibers. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.
What Is Acute Glaucoma?
Acute glaucoma is one of the many different glaucoma types (see Types of Glaucoma). It is much less common than chronic glaucoma (also known as open angle glaucoma). However, acute glaucoma is very serious because it can cause rapid damage and loss of vision; it can also erupt in violent attacks and intense pain, rather than emerging subtly.
This condition occurs in less than 10 percent of glaucoma cases.
Other names for acute glaucoma include:
•Closed angle glaucoma
•Angle closure glaucoma
•Narrow angle glaucoma.
How Acute Glaucoma Affects the Eye
The cornea is the clear outer covering of the eye. Separating it from the iris (the colored part) is the anterior chamber, a space filled and inflated by aqueous humor. This clear fluid (unrelated to the tears that bathe the outside surface of the cornea) starts in the ciliary body just behind the iris. It circulates in the anterior chamber, nourishing the eye's delicate tissue and keeping it from collapsing.
To maintain equilibrium, the aqueous humor drains through a porous tissue in the angle in front of the iris, where it meets the cornea, called the trabecular meshwork.
If the aqueous humor cannot drain properly because the iris is pushing against the cornea (as in acute glaucoma), it backs up, putting pressure on the gel in the vitreous cavity at the center of the eye. Eventually, the building pressure affects the delicate optic nerve at the rear of the eye. Since the optic nerve transmits visual images to the brain, any damage to it reduces vision.
The optic nerve is a bundle of more than one million nerve fibers. It connects the retina to the brain. The retina is the light-sensitive tissue at the back of the eye. A healthy optic nerve is necessary for good vision.
Glaucoma Research.
Doctors and scientists all over the country are conducting research on glaucoma. These studies are designed to answer important questions and to find out whether new approaches are safe and effective. This research has already led to many advances, and researchers continue to search for more effective methods for dealing with glaucoma.
Ongoing glaucoma research aims to simplify medication demands while reducing side effects. For instance, the nuisance of taking preventive medications several times a day discourages some people from protecting themselves fully. Work is under way to perfect a once-a-week eye preparation and once-a-day eyedrops to ease the use of topical glaucoma medicines. Already, dispenser tips that measure more consistent doses of eyedrops are improving their use.
In addition, a large amount of research is being done to learn what causes glaucoma and to improve diagnosis and treatment. For instance, a number of glaucoma research studies are designed to find out what causes fluid pressure to increase in the eye. By learning more about this process, doctors may be able to find the exact cause of glaucoma and better understand how to prevent and treat it.
Research is also being conducted to learn more about who is likely to get glaucoma, when to treat people with increased pressure, and which treatment method to use first.
In order for glaucoma research to be conducted, volunteers are needed. People who join research studies have the first chance to benefit from treatments that have shown promise in earlier research. They also make an important contribution to medical science by helping doctors learn more about glaucoma. Although research trials may pose some risks, researchers take careful steps to protect their patients
Ongoing glaucoma research aims to simplify medication demands while reducing side effects. For instance, the nuisance of taking preventive medications several times a day discourages some people from protecting themselves fully. Work is under way to perfect a once-a-week eye preparation and once-a-day eyedrops to ease the use of topical glaucoma medicines. Already, dispenser tips that measure more consistent doses of eyedrops are improving their use.
In addition, a large amount of research is being done to learn what causes glaucoma and to improve diagnosis and treatment. For instance, a number of glaucoma research studies are designed to find out what causes fluid pressure to increase in the eye. By learning more about this process, doctors may be able to find the exact cause of glaucoma and better understand how to prevent and treat it.
Research is also being conducted to learn more about who is likely to get glaucoma, when to treat people with increased pressure, and which treatment method to use first.
In order for glaucoma research to be conducted, volunteers are needed. People who join research studies have the first chance to benefit from treatments that have shown promise in earlier research. They also make an important contribution to medical science by helping doctors learn more about glaucoma. Although research trials may pose some risks, researchers take careful steps to protect their patients
Glaucoma SymptomsThe type of glaucoma.
Glaucoma SymptomsThe type of glaucoma a person has will affect the symptoms of glaucoma that person experiences. However, all symptoms inhibit vision in one way or another. Common signs and symptoms of the condition include cloudy eyes, sensitivity to light, and loss of side (peripheral) vision.
Open angle glaucoma typically affects people over the age of 50. At first, a person with open angle glaucoma has no symptoms; the condition causes no pain, and vision stays normal.
However, as the condition progresses, a person with open angle glaucoma may notice a gradual failure of side vision (objects in front may be clear, but objects to the side may be missed). This may seem similar to looking into a tunnel.
If left untreated, glaucoma can begin to cause a loss of straight-ahead vision and eventually lead to irreversible blindness.
Primary angle-closure glaucoma (also known as acute glaucoma) is another form of glaucoma (see Types of Glaucoma). Unlike symptoms seen with open angle glaucoma, symptoms with this type begin suddenly and violently.
In angle closure glaucoma, the fluid at the front of the eye cannot reach the angle and leave the eye. The angle gets blocked by part of the iris. People with this type of glaucoma have a sudden increase in eye pressure.
As a result, signs and symptoms of angle closure glaucoma include:
•Severe pain
•Nausea
•Redness of the eye
•Blurred vision.
If you have these symptoms, you need to seek treatment immediately. This is a medical emergency. If your doctor is unavailable, go to the nearest hospital or clinic.
Open angle glaucoma typically affects people over the age of 50. At first, a person with open angle glaucoma has no symptoms; the condition causes no pain, and vision stays normal.
However, as the condition progresses, a person with open angle glaucoma may notice a gradual failure of side vision (objects in front may be clear, but objects to the side may be missed). This may seem similar to looking into a tunnel.
If left untreated, glaucoma can begin to cause a loss of straight-ahead vision and eventually lead to irreversible blindness.
Primary angle-closure glaucoma (also known as acute glaucoma) is another form of glaucoma (see Types of Glaucoma). Unlike symptoms seen with open angle glaucoma, symptoms with this type begin suddenly and violently.
In angle closure glaucoma, the fluid at the front of the eye cannot reach the angle and leave the eye. The angle gets blocked by part of the iris. People with this type of glaucoma have a sudden increase in eye pressure.
As a result, signs and symptoms of angle closure glaucoma include:
•Severe pain
•Nausea
•Redness of the eye
•Blurred vision.
If you have these symptoms, you need to seek treatment immediately. This is a medical emergency. If your doctor is unavailable, go to the nearest hospital or clinic.
Everyone should be concerned about glaucoma?
Everyone should be concerned about glaucoma and its effects. It is important for each of us, from infants to senior citizens, to have our eyes checked regularly, because early detection and treatment of glaucoma are the only way to prevent vision impairment and blindness. There are a few factors related to this disease which tend to put some people at greater risk:
•People over the age of 40.
While glaucoma can develop in younger patients, it occurs more frequently as we get older. •People who have a family history of glaucoma.
Glaucoma appears to run in families. The tendency for developing glaucoma may be inherited. However, just because someone in your family has glaucoma does not mean that you will necessarily develop the disease. •People with abnormally high intraocular pressure (IOP).
High IOP is the most important risk factor for glaucomatous damage. •People of African-American, Hispanic, or Asian-American descent.
African-Americans and Hispanics have a greater tendency for developing primary open-angle glaucoma than do people of other races. Asian-Americans are more prone to develop angle-closure glaucoma and normal-tension glaucoma.
•People who have: ◦Diabetes ◦Myopia (nearsightedness) ◦Regular, long-term steroid/cortisone use ◦A previous eye injury ◦A family history of glaucoma
◦Extremely high or low blood pressure
Everyone under 40 should have a comprehensive eye examination every three to four years. Individuals under 40 with one of the above risk factors should get tested every one and a half to two years. Everyone 40 years or older should have a comprehensive eye examination every one and a half to two years. If you are 40 and have an additional risk factor listed above, get tested annually. Anyone with high risk factors should be tested every year or two after 35.
•People over the age of 40.
While glaucoma can develop in younger patients, it occurs more frequently as we get older. •People who have a family history of glaucoma.
Glaucoma appears to run in families. The tendency for developing glaucoma may be inherited. However, just because someone in your family has glaucoma does not mean that you will necessarily develop the disease. •People with abnormally high intraocular pressure (IOP).
High IOP is the most important risk factor for glaucomatous damage. •People of African-American, Hispanic, or Asian-American descent.
African-Americans and Hispanics have a greater tendency for developing primary open-angle glaucoma than do people of other races. Asian-Americans are more prone to develop angle-closure glaucoma and normal-tension glaucoma.
•People who have: ◦Diabetes ◦Myopia (nearsightedness) ◦Regular, long-term steroid/cortisone use ◦A previous eye injury ◦A family history of glaucoma
◦Extremely high or low blood pressure
Everyone under 40 should have a comprehensive eye examination every three to four years. Individuals under 40 with one of the above risk factors should get tested every one and a half to two years. Everyone 40 years or older should have a comprehensive eye examination every one and a half to two years. If you are 40 and have an additional risk factor listed above, get tested annually. Anyone with high risk factors should be tested every year or two after 35.
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