Glaucoma Basics & FAQs

Glaucoma is an eye problem that can cause vision loss or blindness. It happens because a part of the eye called the optic nerve gets damaged.  But Glaucoma can be prevented with timely care.

Sometimes, glaucoma does not show any signs until it is in the advanced stages. Glaucoma cannot be cured, but it can be managed with a doctor’s help. You may need to take medicine and see your eye doctor regularly.

There are three important parts of the eye: the optic nerve, the ciliary body, and the angle of the front part of the eye. 

  1. The optic nerve is like a cable that sends pictures from your eye to your brain. 
  2. The ciliary body is where the eye makes a watery liquid that helps the front part of your eye stay healthy. 
  3. The angle of the front part of your eye is like a tiny space between the clear part of your eye and the colored part. When too much liquid builds up, it can make the pressure in your eye go up, and that can damage your eye.

High eye pressure alone doesn't mean you have glaucoma. Many people with high eye pressure don't have glaucoma and might not develop it. But, if you do have glaucoma, high eye pressure gives a higher risk of vision loss over time compared to people with lower eye pressure. So, treating high eye pressure is important in glaucoma care to prevent or slow down vision loss.

Yes, there are different types of glaucoma: 

  1. It is the main problem (primary) or caused by something else (secondary). 
  2. How the front part of the eye is shaped: either open or closed. 
  3. Whether it lasts a long time (chronic) or happens suddenly (acute). 

Most people have the slow kind where the angle is open.

The majority of glaucoma cases in North America and Europe are associated with elevation of the intraocular pressure. Elevated intraocular pressure could result from either an excessive production of aqueous humor from the ciliary body or an obstruction of aqueous humor outflow through the chamber angle (trabecular meshwork). In fact, virtually all elevation of intraocular pressure arises from some form of blockade of aqueous humor outflow through the trabecular meshwork. Some patients exhibit the progressive optic nerve damage of glaucoma but seldom or never manifest increased intraocular pressure. Controversy exists about whether these individuals have exquisitely pressure-sensitive optic nerves or whether other damaging factors, such as compromised circulation, cause the optic neuropathy. Glaucomatous optic nerve damage without elevated intraocular pressure is sometimes referred to as "low tension glaucoma" or "normal pressure glaucoma."

The optic nerve is like a cable connecting the eye to the brain. When the optic nerve gets damaged, it can lead to permanent vision loss. The good news is that doctors can use a tool to look at the optic nerve and spot the early signs of glaucoma.

Glaucoma can also cause parts of the optic nerve to get thinner. This can lead to vision problems, too.

Early vision loss happens in the side part of your vision. It is slow, so you might not notice it at first.

Doctors can spot changes in your optic nerve early, even before you lose a lot of vision. They use special tests to check your side vision, called the "visual field."

Glaucoma damage starts from the blind spot in your eye, curves around the center, and stops suddenly on the inner side. So, doctors watch these changes closely to manage glaucoma and protect your vision.

The eye is like a basketball, and it needs to have the right amount of pressure inside to work properly. Doctors will measure your eye pressure with special tools. If your eye pressure is too high, it could mean you have glaucoma.

Your vision and eye pressure will be checked, and your doctor will check your eyes using a special microscope and lenses. You might get eye drops to dilate your eyes and check your eye pressure. Dilation will make the black part of your eyes (pupils) big for a few hours and make things brighter than usual. Sunglasses may help while you are waiting for your pupils to go back to their normal size. Your doctor may get some pictures of your optic nerve to look at how healthy it is, and a visual field test, to check your side and central vision. You look straight ahead at a point while your chin and head rest in a large bowl-like machine. You press a button every time you see a light flash, but do not move your eyes. Your doctor will review these tests from one visit to the next. Your eye exam could take a few hours depending on how much testing you need, and how busy the office is.

Pigmentary glaucoma is a type of open-angle glaucoma where there is more than average pigment in the front of the eye because of pigment loss from the back surface of the colored part of your eye (iris). People with this condition have pigment clogging the natural drain of the eye (trabecular meshwork), pigment on the inner lining of the cornea  (“Krukenberg spindle”), and gaps in the iris. Patients with these findings who have optic nerve damage and/or visual field loss are diagnosed with pigmentary glaucoma. Treatment options are the same as other open-angle glaucomas including medical therapy, lasers, and surgeries.

This kind of glaucoma is linked to diabetes and happens when new blood vessels grow and block the eye's fluid from draining, making the pressure go up. It is a complex condition that needs careful attention.

Some babies are born with glaucoma.

Babies with this type of glaucoma might be sensitive to light, have watery eyes, and blink a lot. Their eyes might look big and cloudy. It is important to get treatment from an eye doctor quickly to prevent permanent blindness.

The doctor’s goal is to bring down the pressure inside the eye. That can help slow down or stop the disease in most cases.

There are three main ways to lower eye pressure in glaucoma: using special eye drops, using laser therapy, or having surgery. The goal is to keep your vision stable and protect the optic nerve from further damage.

Angle-closure glaucoma is usually treated with eyedrops and laser therapy. Eyedrops are used to lower your eye pressure. Laser treatments include laser peripheral iridotomy (LPI) to create a hole in the iris to improve drainage. These treatments are used to prevent sudden angle closure and keep vision. Surgery may be needed as well. Regular check-ups with your eye doctor are important to manage glaucoma.

During the early 1970's, attempts were made with a variety of lasers to enhance aqueous humor outflow through the trabecular meshwork in open angle glaucoma by puncturing the trabecular meshwork with the laser energy. Despite the failure of these procedures to create holes in the trabecular meshwork, a subsequent decrease in the intraocular pressure, several days to weeks following some of the procedures, was often observed. In 1979, Wise and Witter published a pilot study describing an argon laser procedure for the control of intraocular pressure. This technique, known as argon laser trabeculoplasty, has changed little since its original description. Many theories attempting to explain the effect of the trabeculoplasty laser burns have emerged. It is now thought that a cascade of biological events that involves renewal of trabecular meshwork cells and accelerated turnover of the extracellular matrix, or tissues between the trabecular cells, enhances outflow through the trabecular meshwork following laser treatment. Argon laser trabeculoplasty is a relatively uncomplicated office procedure and has gained wide acceptance in the treatment of open angle glaucoma. In approximately 80% of eyes treated with argon laser trabeculoplasty, a significant lowering of the intraocular pressure will be achieved. However, the intraocular pressure lowering effect will diminish over time and approximately 10% of initially successful treatments will fail with each year. In patients in whom the initial laser trabeculoplasty was successful, additional laser therapy may be warranted. A modification of this therapy, Selective Laser Trabeculoplasty, is also available to treat open angle glaucoma.

Trabeculectomy or Filtering Surgery

Trabeculectomy is the most common operation for the control of elevated intraocular pressure in adult glaucoma. Various filtering procedures have been developed to shunt the aqueous humor from the anterior chamber to a reservoir under the conjunctiva on the surface of the eye. These procedures provide an alternative low-resistance pathway for aqueous humor egress from the eye. It is believed that the aqueous humor either filters through the conjunctiva from the reservoir, mixing with the tears, or it is absorbed by the blood vessels on the surface of the eye. Postoperative management includes topical dilating drops and antibiotics for the first one to two weeks following surgery. Topical corticosteroids are also used to suppress inflammation. The corticosteroid therapy is thought to reduce scar formation and failure of the filtering bleb. Youth, skin pigmentation, previous surgery, and secondary glaucoma greatly increase the risk of failure. The majority of surgical patients receive some form of additional chemical antimetabolite therapy, either during surgery by sponge application or post operatively as subconjunctival injections. 5-Fluorouracil or Mitomycin-C are the most commonly used antimetabolite adjuncts to trabeculectomy surgery. In addition, a variety of artificial drainage devices are available that employ a plastic shunt tube to divert the aqueous humor from the anterior chamber into the space behind the eye, where it is resorbed. These glaucoma tube shunts are generally reserved for eyes in which trabeculectomy surgery has failed or in which failure is likely due to extensive scar tissue formation, such as neovascular glaucoma.

If you have glaucoma, you need to see your doctor regularly to check your eyes and make sure treatment is working.

Glaucoma may develop after ocular trauma. Penetrating injuries to the globe disrupt, or even destroy, intraocular contents and may lead to sustained elevation of intraocular pressure and glaucoma. (see Ocular Trauma) A more subtle, insidious glaucoma may arise from blunt ocular injury or ocular contusion, as occurs when the globe is struck with a fist, ball or other object. Blunt injury temporarily deforms the globe, causing shearing between its internal tissue layers. These shearing forces may tear the insertion of the iris (iridodialysis) or ciliary body (cyclodialysis) from its attachment to the sclera. Most commonly, the fibers of the ciliary muscle that both controls accommodation and modulates aqueous humor outflow become detached, leading to collapse of the trabecular meshwork (known as angle recession) and subsequent secondary glaucoma.

Acutely, the contused eye typically presents with intraocular bleeding (hyphema), and the intraocular pressure may be low, normal, or elevated. Angle recession glaucoma may not manifest for months or even years after the original injury. Treatment of glaucoma from blunt ocular trauma follows a similar protocol to more common open angle glaucomas, except that these eyes do not respond well to pupil-constricting drops such as pilocarpine because of the damage of the ciliary muscle. Because of the damage to the trabecular meshwork, laser trabeculoplasty is similarly ineffective. Thus, when regular glaucoma drops are ineffective, filtration surgery usually becomes necessary.

Not only can trauma cause glaucoma, but glaucoma can cause trauma.  This is because glaucoma effects your side vision, which we use to see the floor as we walk, the walls to our sides, and other cars when we drive.  Glaucoma has been shown to increase the risk of falls and bumping into objects.  It is important to get checked for glaucoma, and to treat the disease early and prevent future vision loss.

Trauma to the eye or face is a rare but serious cause of glaucoma.  Trauma damages the drainage system of the eye, so the natural fluid in the eye cannot drain out.  When the fluid cannot drain out properly, the pressure in the eye builds up and can cause glaucoma.  Sometimes this damage can be seen during an eye exam.  Glaucoma from trauma can appear quickly or years later, so it is important to continue to get your eyes checked after any trauma to the eye.

Glaucoma at a Glance

Early Symptoms:
Often none

Later Symptoms:
Loss of side (peripheral) vision, blind spots, blindness

Dilated eye exam with eye pressure and visual field testing to test your side vision

Medicine (usually eye drops), laser, or surgery

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