Causes and Risk Factors of Glaucoma

Glaucoma can refer to any of several types and conditions, and they may vary in causes and risk factors. There are a variety of forms of glaucoma that can lead to damage of the optic nerve and potentially result in blindness.

Those who have high pressure in the eye tend to find themselves more at risk for glaucoma, but others without any eye pressure issues can get the condition as well. Unfortunately, not all the causes of glaucoma are currently known.

Diagrams of how glaucoma occurs in the eye

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Common Causes

There are a variety of types of this disease that someone may have, each with unique causes to consider.

Open-Angle Glaucoma

This hands down is the most common form, with up to 90% of those in America with glaucoma identified as having open-angle disease. With this type of glaucoma, fluid builds up in the eye when the drainage canals here become sluggish over time. This puts the optic nerve under pressure and causes severe damage in some cases.

Exfoliation syndrome is a type of open-angle glaucoma. With this, there's a buildup of whitish material on the lens, as well clogging the angle. The result is an increase in eye pressure that may damage the optic nerve.

Likewise, pigmentary glaucoma can be another subtype. With this, the colored portion of the eye (the iris) bows back and may rub against other structures. Pigment particles then may clog the eye's drainage system. This usually affects young White males who are nearsighted.

Normal-Tension Glaucoma

Even when eye pressure is normal or close to it, it's possible to have vision damage from glaucoma. Such optic nerve issues occur in as many as 1 in 3 people diagnosed with what's known as low-pressure or normal-tension glaucoma. Asians and Asian-Americans are more likely to be affected by this.

Experts unfortunately aren't sure what the cause is here. It's possible that some peoples' optic nerves are just more sensitive than others.

Angle-Closure Glaucoma

This type of glaucoma, also known as narrow angle, is often much more sudden, occurring when the drainage area between the colored part of the eye and the clear dome becomes blocked. With the aqueous fluid dammed up, this can cause a dangerous immediate rise in eye pressure.

Symptoms here may include:

  • Intense eye pain
  • Blurry vision
  • Headache
  • Rainbow auras around lights
  • Nausea
  • Vomiting

Unless this is treated rapidly, blindness may occur. Those of Asian or African ancestry are more likely to be affected by this form of glaucoma.

Congenital Glaucoma

This affects babies who are born with an eye drainage system that clears fluid more slowly than usual. On the upside, when treated early, children usually develop good vision.

Secondary Glaucoma

Sometimes glaucoma develops as a result of another health condition that affects the eye. Some things that can lead to secondary glaucoma include:

  • Cataract
  • Diabetes, high-blood pressure, or other disease-related complications
  • Eye tumors
  • Eye injury
  • Steroid use
  • Serious eye inflammation

Genetics

While genetics is not always a factor, in some families there may indeed be a connection. Here are some of associations with genes found so far, as reported by the Glaucoma Research Foundation.

With primary open-angle glaucoma, there are currently three genes that are highly predictive of developing the condition. However, altogether these account for less than 10% of such glaucoma cases.

In primary congenital glaucoma cases, which is the most common type among children, mutations in the CYP1B1 gene have been identified as the cause worldwide. But in the United States, this mutation only accounts for 15% of childhood cases.

For primary closed-angle glaucoma, some genes near PLEKHA7, PCMTD1/ST18, and COL11A1 have all been associated with this form of glaucoma. But the role these genes may play in causing this has not yet been identified.

Also, when it comes to exfoliation glaucoma, where white protein is deposited in the drainage system and elsewhere, two genes have been found. Scientists are still working to determine just how these contribute to developing protein deposits.

Cardiovascular

If you have other health issues, such as high blood pressure or heart disease, you may be at higher risk for glaucoma. There's some thinking that in glaucoma insufficient blood flow may be linked to optic nerve damage.

Similar mechanisms may be at play with the two conditions. This may mean someone with glaucoma may have some risk for heart disease. A 2016 study found that those with open-angle glaucoma had a 40% higher possibility of developing ischemic heart disease than those without this condition.

Patients with open-angle glaucoma may also have:

So, if you have glaucoma, it may be helpful to be checked for some of these other conditions as well.

Lifestyle Risk Factors

The lifestyle choices you make may also have an impact on the development of glaucoma and how you fare. These can in many cases influence eye pressure.

Some lifestyle factors that can lower eye pressure include:

  • Aerobic exercise: This is known to bring down eye pressure at least in those without glaucoma. However, studies have not been done specifically in those with the disease.
  • Marijuana use: This can bring eye pressure down for a short 3-to-4 hour period. However, there is no evidence that this can forestall glaucoma advancement and is not recommended as a treatment.
  • Alcohol use: While this lowers eye pressure for a short time, in the long run, daily consumption is associated with a rise in pressure. This has not been found to reduce the chance of developing glaucoma.

Meanwhile, some practices that bring with them the danger of increased eye pressure include:

  • Weightlifting: The strain of this, particularly if combined with holding your breath, can increase eye pressure and is not recommended.
  • Head-down yoga positions: Head-down positions such as Downward-Facing Dog, Standing Forward Fold, Plow pose, and Legs-up-the-Wall pose have all been found to increase eye pressure.
  • Blowing into wind instruments: Eye pressure can increase when playing high-resistance wind instruments such as the trumpet or the oboe.
  • Drinking coffee: This is known to cause a rise in eye pressure for a short time. So, while one cup of caffeinated coffee in moderation is fine, five or more have been known to make glaucoma risk greater.

A Word From Verywell

The more you know about your glaucoma diagnosis the better. A better understanding can hopefully make for a better outcome here.

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Article Sources
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  2. Cleveland Clinic. Glaucoma.

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  6. Glaucoma Research Foundation, Do lifestyle choices affect glaucoma, October 29, 2017

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