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The Different Types of Glaucoma [Open Angle, Closed Angle, & More]

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The Different Types of Glaucoma [Open Angle, Closed Angle, & More]

Close up of older gentleman's eye with signs of glaucoma

You may have heard of glaucoma before, but did you know there are multiple varieties of the condition? Glaucoma symptoms can be minimal, but your optometrist can diagnose any early signs through an eye exam

Knowing the symptoms and causes of the different types of glaucoma helps to protect your ocular health. Learn more about the various forms of glaucoma below. 

What is Glaucoma?

Glaucoma is an eye disorder that causes damage to the optic nerve. Damage to the nerve tissue can eventually lead to vision loss, making glaucoma one of the leading causes of blindness in adults over 60

Vision loss is irreparable, but medications and other treatments can effectively manage eye pressure. Your visual health is vital, so it’s important to understand the different forms of glaucoma and their causes. 

Types of Glaucoma

Open-Angle Glaucoma

Open-angle glaucoma affects approximately 3 million Americans. This type of glaucoma occurs when fluid cannot drain out of the eye. The drainage canals of the eye become clogged, similarly to your kitchen sink. Eye pressure slowly increases and damages the optic nerve. 

Glaucoma affects many people, but you may not notice any problems until it’s too late. Open-angle glaucoma has no early or painful symptoms, and you may not notice anything is wrong until your vision is affected. Some potential symptoms are: 

  • Blind spots in your peripheral or central vision
  • Tunnel vision 

An annual eye exam is the best way to identify any signs of glaucoma. 

Angle-Closure Glaucoma

Angle-closure glaucoma is less common, but a serious medical condition. This variant occurs when the iris is not wide or open enough. The iris blocks the drainage canals and traps fluid which can cause a pressure build-up in the eye.

Angle-closure glaucoma occurs gradually or rapidly, and symptoms can include: 

  • Severe head or eye pain
  • Nausea or vomiting 
  • Hazy, blurred vision
  • Sudden vision loss
  • Seeing rainbow-coloured circles near bright lights

If you experience any of these symptoms, visit your optometrist as soon as possible. 

Normal-Tension Glaucoma 

Normal-tension glaucoma differs from other forms of this disease. Glaucoma usually causes increased pressure in your eye, but pressure stays low or consistent with normal-tension glaucoma. 

Doctors are generally unsure why this happens, but this condition can be diagnosed by examining the optic nerve. If the optic nerve is damaged, your optometrist can provide several forms of treatment.

Congenital Glaucoma

Congenital glaucoma (also known as childhood glaucoma) is a rare condition usually caused by drainage blockage or an underlying medical condition. This condition can be present from birth or develop in early adolescence. Signs of congenital glaucoma include: 

  • Cloudy eyes
  • Light sensitivity 
  • Abnormally large eyes
  • Uncontrollable tearing 

Although lost vision cannot be restored, long-term management of congenital glaucoma allows people to live full lives. Common treatment methods are eye drops and oral medication. 

Secondary Glaucoma 

Secondary glaucoma is any form of glaucoma with a diagnosable source. This condition can be caused by injuries, medical conditions, or medications. There are several types of secondary glaucoma, including: 

Each form of glaucoma has various potential causes and treatments, and an optometrist can help you diagnose and treat any eye conditions. 

older woman having her eyes examined


Glaucoma treatment works to reduce pressure in the eyes. There are a variety of treatment options depending on the type and severity of glaucoma you’re experiencing. Your optometrist will determine which treatment is most effective, such as: 

  • Prescription eye drops
  • Medication 
  • Laser surgery
  • Conventional surgery
  • Drainage implants

Prescriptive eye drops and medication are common remedies and are usually attempted before surgery is recommended. If you need surgical care, a referral to a specialist will be made. 

Risk Factors 

Glaucoma can affect anyone, but several factors increase the risk of glaucoma development: 


Adults over 60 have an increased risk of developing glaucoma. This risk slightly increases each year. Annual eye exams can help to ensure visual health. 


Your ethnic background can affect the likelihood of developing glaucoma. People of African descent are more likely to develop glaucoma, while angle-closure glaucoma is more prominent in people of Asian descent and Native Alaskans. Furthermore, people of Japanese descent have an increased likelihood of developing low-tension glaucoma. 

Family History

If there is a history of glaucoma in your family, there is an increased risk. At an eye exam, your optometrist will ask you about your family medical history. 

Eye Injuries

Eye trauma can result in rapid or future increases in eye pressure. Any injuries can dislocate the lens and potentially block drainage in the eye. 

Eye-Related Factors 

Eye-related factors such as a thin cornea or optic nerve sensitivity increase the risk of glaucoma development. Retinal detachment, eye tumours and inflammation can contribute to a risk of glaucoma. 

Help is Available 

Knowing the causes and symptoms of glaucoma can help you preserve your vision health. Visit your optometrist for a regular eye exam and book an appointment if you experience any symptoms of glaucoma. 

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