- Primary Open-Angle Glaucoma
This is the most common type of glaucoma, and accounts for at least 90% of all glaucoma cases. It happens gradually, where the eye does not drain fluid as well as it should (like a clogged drain). As a result, eye pressure builds and starts to damage the optic nerve. This type of glaucoma is painless and causes no vision changes at first.
Some people can have optic nerves that are sensitive to normal eye pressure. This means their risk of getting glaucoma is higher than normal. Regular eye exams are important to find early signs of damage to their optic nerve.
- Normal Tension Glaucoma (NTG)
Also called low-tension or normal-pressure glaucoma. In normal-tension glaucoma the optic nerve is damaged even though the eye pressure is not very high. We still don’t know why some people’s optic nerves are damaged even though they have almost normal pressure levels.
NTG is diagnosed by observing the optic nerve for signs of damage. This is done by dilated examination by an Ophthalmologist on a regular basis, along with visiual field testing.
- Angle Closure Glaucoma (also called “closed-angle glaucoma” or “narrow-angle glaucoma”)
This type happens when someone’s iris is very close to the drainage angle in their eye. The iris can end up blocking the drainage angle. You can think of it like a piece of paper sliding over a sink drain. When the drainage angle gets completely blocked, eye pressure rises very quickly. This is called an acute attack. It is a true eye emergency, and you should call your ophthalmologist right away or you might go blind.
- Congenital Glaucoma
This type of glaucoma occurs in babies when there is incorrect or incomplete development of the eye’s drainage canals during the prenatal period. This is a rare condition that may be inherited. When uncomplicated, microsurgery can often correct the structural defects. Other cases are treated with medication and surgery.
Other Variants of Open and Narrow Angle Glaucoma include:
- Secondary Glaucoma
- Pigmentary Glaucoma
- Pseudoexfoliative Glaucoma
- Traumatic Glaucoma
- Neovascular Glaucoma
- Irido Corneal Endothelial Syndrome (ICE)
- Uveitic Glaucoma
Fortunately, for most patients the answer is no. Blindness does occur from glaucoma, but it is a relatively rare occurrence in about 5% of glaucoma patients. However, sight impairment is more common and occurs in about 10% of patients. Correct treatment and follow-up will stabilize the vast majority of patients with glaucoma.
As a newly diagnosed person with glaucoma, you may need to have your eye pressure checked every week or month until it is under control. Even when your eye pressure is at a safe level, you may need to see your doctor several times a year for checkups. How often you get checked by your eye doctor is part of the treatment plan you and your doctor will decide together.
People who have a family history of glaucoma may be at higher risk for developing the condition, so you should encourage your family members to go to an eye doctor to have their eye pressure and optic nerves checked regularly. Many people are unaware of the importance of eye checkups and do not know that individuals with glaucoma may have no symptoms.
Glaucoma is not curable, and vision lost cannot be restored. With medication, laser treatment and surgery, it is possible to slow or stop further loss of vision. Since Open-Angle Glaucoma cannot be cured, it must be monitored for life. Diagnosis is the first step to preserving your vision.
Some forms of glaucoma are inherited, and many scientists worldwide are studying genes and their influence on glaucoma. But in many cases, glaucoma is not inherited, and the factors leading to disease onset are not well understood.
In the retina, neurons (nerve cells) and the optic nerve are not regenerated once they are lost. However, many research centers are working to develop ways for replacing lost retinal neurons. If successful, this research could one day be applied to glaucoma and other neuro degenerative diseases.