What Is Glaucoma

Glaucoma occurs when an excess of ocular (eye) fluid does not drain properly, causing damage to the optic nerve and resulting in blurred vision, a narrowed field of vision with some loss of peripheral vision, and eventually total blindness.

The three main types of glaucoma are:

  1. Open-angle glaucoma. This is the most common form, also called primary open-angle glaucoma. In open-angle glaucoma, the trabecular meshwork, a spongy tissue near the cornea and  iris that drains ocular fluid, slowly becomes less effective at doing its job. When this occurs, intraocular pressure (IOP), rises to dangerous levels. This condition is almost always asymptomatic in the early stages. Thus, the patient is often unaware of the developing condition.
  2. Normal-tension glaucoma. In normal-tension glaucoma, damage occurs to the optic nerve despite an IOP within the normal range, between 10-20 millimeters of mercury (mm Hg).
  3. Closed-angle glaucoma, also called narrow-angle glaucoma or angle-closure glaucoma. This less common form of glaucoma happens suddenly, when the iris (colored part of the eye) shifts positions and blocks the flow of fluid through a drainage channel called the drainage angle. This can cause IOP to raise rapidly, necessitating emergency response, which may include emergent surgery.

Glaucoma affects more than 60.5 million people worldwide, a number that is expected to grow as the global population ages. Glaucoma is a leading cause of blindness in the US, and costs the U.S. economy around $2.86 billion each year in health care expenditures and lost productivity.

What Causes Glaucoma

Glaucoma occurs when the eye in unable to balance fluid retention with fluid release, causing eye pressure to increase. However increased eye pressure is not the only cause of glaucoma. Glaucoma can also occur in individuals with normal eye pressure.

Risk Factors For Glaucoma

Open-angle glaucoma cases are often idiopathic, meaning they have no known cause. However, the following factors may increase the risk of developing the condition.

  • HereditySiblings of people with glaucoma are more likely to contract the condition.Sons and daughter of people with glaucoma are not a susceptible as siblings.
  • Injury to the eye
  • Inflammation of the eye
  • Diabetes
  • Steroid– containing medications, including pills, eye drops, and spray

The following are risk factors for closed-angle glaucoma:

  • A congenitally narrow drainage area in the eye. Certain individuals are born with a naturally narrow drainage area in the eye, putting them at a higher risk of blockage or malfunctioning.
  • Race. Closed angle glaucoma is known to be more prevalent among Asians  and possibly among east Indians as well.
  • Sex. Women are approximately 50% more likely to develop closed angle glaucoma than men.

Diagnosing Glaucoma

If you or your doctor notice changes in your vision that suggest an eye disease or condition, you may be referred to an ophthalmologist (medical doctor specializing in the eye) for diagnosis. Below are the leading methods of diagnosis for glaucoma:

  • Tonometer ExaminationIn this test, a tonometer is used measure intraocular pressure (IOP). In healthy individuals, IOP generally falls between 10 and 21 mm of mercury (mm Hg). Optic nerve damage is typically a result of IOPs above 21 mm Hg, though there are cases when optic damage occurs at IOPs lower than 21, and cases where no damage occurs at pressures higher than 21 mm Hg.
  • Gonioscopy. In a gonioscopy, the eye is dilated and numbed with anesthetic drops in order for a specialized contact lens to be place on the lens of the eye. The mirrors within this specialized lens allow the doctor to view the drainage angle to check for potential blockage.  
  • Ophthalmoscope examination. In an ophthalmoscope examination, a doctor uses an ophthalmoscope to magnify the interior and rear portions of your eye. This can detect changes in the optic nerve and damage to the retina.
  • Visual Field TestDuring a visual field test, patients are asked to look though an optical device called a perimeter at a yellow field on which blue spots will randomly appear. When a blue spot is seen, patients are asked to click a handset that they are holding, which feeds back to a central computer. Doctors are then able to see in what areas patients are able to see and in what areas they have blind spots, even those that may not be detectable in day to day life
  • Pachymeter examinationDuring a pachymeter examination, doctors anesthetize the eyes and then place a probe on the cornea called a pachymeter, which measures the thickness of your central cornea. Your central corneal thickness, or CCT, can influence the interpretation of your IOP as measured by tonometers. A thin CCT means that the IOP is most likely higher than was measured with the tonometer, while a thick CCT is most likely indicative of a lower IOP

Symptoms of Glaucoma

For open-angle glaucoma, there are almost never any symptoms at the beginning. If the disease progresses, you’ll have blind spots in your peripheral (side) vision.

For closed-angle glaucoma, an attack may bring on the following symptoms quite suddenly.

If you experience any of the following, you should contact a doctor immediately.

  • Severe eye or brow pain
  • Redness of the eye
  • Decreased or blurred vision
  • Seeing colored rainbows or halos
  • Headache
  • Nausea
  • Vomiting


Unfortunately, glaucoma often goes untreated and results in severe vision loss or blindness. According the National Foundation of the Blind, about one in every one in every seven or eight cases of blindness in the US is caused by uncontrolled glaucoma. However, with early detection and continued treatment open-angle glaucoma can be controlled, and blindness can be prevented. As for acute-angle glaucoma, prompt treatment at the start of an attack can help control the attack and may allow vision to return to normal. Failure to treat an attack can result in blindness less than two days after the attack began. If you experience any of the symptoms of an acute-angle glaucoma attack, see a doctor immediately

Living With Glaucoma

In many cases, depending on the eye disease or condition you have and your response to treatment, your vision may not be not noticeably impaired and you won’t experience any pain or only mild discomfort.

However, you may need to compensate for partial loss of vision if you have a condition such as wet AMD that can’t be treated. Ask your eye care specialist about low-vision rehabilitation devices and services that will help you learn coping strategies so that you can to continue to live independently.

Many people with some vision loss have to stop driving. If that happens to you, visit to get information about affordable and convenient ways to maintain your mobility.

Here are some top tips for living well with vision impairment:

  • To wake up, a person may use a talking watch or talking alarm clock.
  • To get dressed someone may have their own system of identifying clothes and colors. They might use safety pins to match the same color outfits together, or use Braille clothing tags.
  • Instruction is available for visually impaired people to learn independent meal preparation skills. Special dots or Braille can be put on conventional and microwave ovens to aid in instruction and use.
  • Someone with low vision might use a dark tablecloth with light colored dishes and a light tablecloth for dark dishes. Contrasting colors help individuals who have some remaining vision better see where things are.
  • Similarly, someone with low vision might use dark mugs or glasses to pour light colored liquid such as milk and light colored mugs or cups to pour coffee or other dark liquids such as tea or hot chocolate.
  • To locate keys, wallet or purse, they might make an effort to put them in the same place all the time so they can be found more easily.
  • For leisure activities a person can watch audio described movies, listen to recorded books called Talking Books, play cards or other adapted games with friends.


Serious eye diseases and conditions often have no symptoms until irreversible damage to vision has been done. If you wear prescription glasses and/or contacts, you probably go to an optometrist for an annual check-up to make sure your prescription hasn’t changed and to order a new batch of contacts if you’re running out of them. Optometrists conduct vision tests to check for basic vision impairment, and can prescribe glasses and contact lenses. They can also spot early warning signs and give you a referral to an ophthalmologist, an eye doctor with a medical doctor degree, for a more thorough examination. If you do not wear contact lenses or glasses, chances are you miss out this periodic optometric screening. Many times, family doctors with conduct a visual acuity test, which is a series of letters decreasing in size on a chart that patients are asked to read to the best of their ability. This gives doctors the opportunity to do as the optometrists would.

The standard recommendation for all adults over the age of 40 is to have an eye exam at least every two years, and for adults over 65, to have an eye exam every year.  According to the National Federation of the Blind, prompt detection and treatment can preserve your vision for a lifetime even if you do contract a serious eye condition or disorder. Schedule an eye exam with an optometrist. If he or she spots any problems that may be of concern, you will most likely be referred to an ophthalmologist, a medical doctor specializing in eyes, for further testing. Be sure to make an appointment with the ophthalmologist and follow recommendations regarding the frequency of follow-ups should any diseases or conditions be detected.

People with diabetes or at risk of developing gestational diabetes are recommended to get additional ophthalmic screening.

The American Academy of Ophthalmology recommends the eye screening schedule:
Type 1 Diabetes: Within five years of being diagnosed and yearly thereafter.
Type 2 Diabetes: At the time of diagnosis and yearly thereafter.
During pregnancy: During the first trimester and follow-ups if indicated.


Our best defense against glaucoma is to have regular checkups, because eye diseases do not always have symptoms. Early detection and treatment are the keys to preventing vision loss.

Beyond that, a healthy diet that has sufficient vitamin and other nutrients will help keep your eyes lubricated and free of infections.

Also, avoid second hand smoke and if you smoke, kick the habit.

Protect your eyes from injury by wearing plastic eye guards if you’re involved in any activity that poses a risk of flying objects or particles.

Finally, remember that overexposure to the sun is just as bad for your eyes as it is for your skin. Wear sunglasses and stay away from tanning beds as UV rays can harm and exacerbate eye conditions.

Medication And Treatment

The following treatments are available for glaucoma patients:

Medicated eye drops, such as prostaglandin analogs, beta blockers, alpha antagonists, and carbonic anhydrase inhibitors, can help to lower intraocular pressure pressure. Typically, one drop of solution is put in each eye every night at bedtime.

Glaucoma surgery For some patients, glaucoma surgery is recommended to improve the flow of fluid out of the eye in order to lower pressure.  Surgical procedures include:

  •  Laser trabeculoplastyis often used to treat open-angle glaucoma. There are two types of trabeculoplasty surgery: argon laser trabeculoplasty (ALT) and selective laser trabeculoplasty (SLT).
  • Laser iridotomyis recommended for people with closed-angle glaucoma and others with narrow drainage angles.
  • Peripheral iridectomyThis is used is to stop an acute closed-angle glaucoma attack. A small piece of the iris is removed. If more conservative treatments are successful, this surgery is not necessary.
  • TrabeculectomyA small flap is made in the outer coating of the eye and a filtration reservoir is made under the membrane that covers the white of the eye.
  • Aqueous shunt surgeryA shunt is a small plastic tube or valve that acts as an artificial an artificial drainage system. That is implanted in the eye through a small incision.

Complementary and Alternative Treatment

Research that has been done on the use of Ginkgo biloba, coenzyme Q10, melatonin, and antioxidants with limited or no evidence of effectiveness. The American Academy of Ophthalmology refutes the widely held belief that marijuana helps treat glaucoma, though this viewpoint is in flux.

When To Contact A Doctor

In addition to your regularly scheduled visits to your eye care professionals, get immediate medical attention if you notice any sudden change in your vision or experience unusual symptoms such as extreme eye pain, burning, itching, redness, or fluid coming out of your eye. Also, get help if you have an eye injury.

Questions For A Doctor

Before you visit your doctor, write down a list of questions and concerns. Consider bringing a friend or family member along who can help you make sure you get all the information you need. In addition, writing down the doctor’s answers and recommendation for later reference is a good idea. Also come prepared with your medical history, information about any allergies you have, your family medical history, and a complete list of all medications you take including over-the-counter herbs and supplements.

Here are some questions you might pose when you visit your optometrist:

  • I started having trouble reading up close not long after I turned 40, so I bought a pair of readers at the drugstore. Is that OK? And did I pick the right strength?
  • I’ve always been nearsighted. Do I now need bifocals or progressive lenses?
  • I’ve heard about progressive contact lenses and monovision lenses. Would one of those options be right for me?
  • My eyes feel dry even when I blink. Is that a sign of a condition I’ve heard about called dry eye?
  • My eyes tear in cold weather, especially when it’s windy out. Is that a bad sign?
  • I work at a computer all day. Is that a risk for eyestrain?
  • Has my prescription changed in the last year? If so, is that a bad sign?

Here are some questions you might pose if you are referred to an ophthalmologist:

  • Which eye diseases or conditions are you screening me for?
  • If you diagnose an eye disease or condition, how much will medication and/or surgery cost?
  • Will the treatments control my problems so that I retain my vision?
  • How often will I need to come back to you for check-ups?
  • Should my adult children be checked if my condition is hereditary?

Are there any lifestyle changes I can make that will help prevent other eye diseases or the progression of the ones I already have?

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